Petitioners:
Concerned Individuals and Belize Organizations
|
Bibliography
of Published Peer-Reviewed Scientific
Documents
Presented To Belize
Pesticide Control Board Registration
Review Committee 30 August 2016 10 a.m. Pesticide Control Board, Central Farm, Cayo, Belize Bibliography
of Peer-Reviewed Documents Supporting Petition to
Ban Glyphosate 1. Glyphosate
Information, Testing, and Use Impact on Plant
Physiology 1.
Noctor,
G.; Foyer, C.H.
Perturbations of amino acid metabolism associated
with glyphosate-dependentinhibition of shikimic acid
metabolism affect cellular redox homeostasis and
alter the abundanceof proteins involved in
photosynthesis and photorespiration. Plant Physiol. 2011, 157,
256268. Abstract: The herbicide glyphosate
inhibits the shikimate pathway of the synthesis of
amino acids such as phenylalanine, tyrosine, and
tryptophan. However, much uncertainty remains
concerning precisely how glyphosate kills plants or
affects cellular redox homeostasis and related
processes in glyphosate-sensitive and
glyphosate-resistant crop plants. To address this
issue, we performed an integrated study of
photosynthesis, leaf proteomes, amino acid profiles,
and redox profiles in the glyphosate-sensitive
soybean (Glycine max) genotype PAN809 and
glyphosate-resistant Roundup Ready Soybean (RRS).
RRS leaves accumulated much more glyphosate than the
sensitive line but showed relatively few changes in
amino acid metabolism. Photosynthesis was unaffected
by glyphosate in RRS leaves, but decreased abundance
of photosynthesis/photorespiratory pathway proteins
was observed together with oxidation of major redox
pools. While treatment of a sensitive genotype with
glyphosate rapidly inhibited photosynthesis and
triggered the appearance of a nitrogen-rich amino
acid profile, there was no evidence of oxidation of
the redox pools. There was, however, an increase in
starvation-associated and defense proteins. We
conclude that glyphosate-dependent inhibition of
soybean leaf metabolism leads to the induction of
defense proteins without sustained oxidation.
Conversely, the accumulation of high levels of
glyphosate in RRS enhances cellular oxidation,
possibly through mechanisms involving stimulation of
the photorespiratory pathway. 2.
de
Mara, N.; Becerril J.M.; Garca-Plazaola,
J.I.;Ndez, A.H.; de Felipe, M.R.;
Fernndez-Pascual, M.New insights on glyphosate mode
of action in nodular metabolism: Role of shikimate
Accumulation. J. Agric. Food Chem. 2006, 54,
26212628. Abstract: The short-term effects of
the herbicide glyphosate (1.25-10 mM) on the growth,
nitrogen fixation, carbohydrate metabolism, and
shikimate pathway were investigated in leaves and
nodules of nodulated lupine plants. All glyphosate
treatments decreased nitrogenase activity rapidly
(24 h) after application, even at the lowest and
sublethal dose used (1.25 mM). This early effect on
nitrogenase could not be related to either damage to
nitrogenase components (I and II) or limitation of
carbohydrates supplied by the host plant. In fact,
further exposure to increasing glyphosate
concentrations (5 mM) and greater time after
exposure (5 days) decreased nodule starch content
and sucrose synthase (SS; EC 2.4.1.13) activity but
increased sucrose content within the nodule. These
effects were accompanied by a great inhibition of
the activity of phosphoenolpyruvate carboxylase
(PEPC; EC 4.1.1.31). There were remarkable and rapid
effects on the increase of shikimic and
protocatechuic (PCA) acids in nodules and leaves
after herbicide application. On the basis of the
role of shikimic acid and PCA in the regulation of
PEPC, as potent competitive inhibitors, this
additional effect provoked by glyphosate on
5-enolpyruvylshikimic-3-phosphate synthase enzyme
(EPSPS; EC 2.5.1.19) inhibition would divert most
PEP into the shikimate pathway, depriving energy
substrates to bacteroids to maintain nitrogen
fixation. These findings provide a new explanation
for the effectiveness of glyphosate as a herbicide in other plant
tissues, for the observed differences in tolerance
among species or cultivars, and for the transitory
effects on glyphosate-resistant transgenic crops
under several environmental conditions. Ingredients:
Active and Inert 3.
Mesnage, Robin, et al., Major
Pesticides Are More Toxic to Human Cells than Their
Declared Active Principles, BioMed
Research International (December 2013).
Abstract: Pesticides are used
throughout the world as mixtures called
formulations. They contain adjuvants, which are
often kept confidential and are called inerts by the
manufacturing companies, plus a declared active
principle, which is usually tested alone. We tested
the toxicity of 9 pesticides, comparing active
principles and their formulations, on three human
cell lines (HepG2, HEK293, and JEG3). Glyphosate,
isoproturon, fluroxypyr, pirimicarb, imidacloprid,
acetamiprid, tebuconazole, epoxiconazole, and
prochloraz constitute, respectively, the active
principles of 3 major herbicides, 3 insecticides,
and 3 fungicides. We measured mitochondrial
activities, membrane degradations, and caspases 3/7
activities. Fungicides were the most toxic from
concentrations 300600 times lower than agricultural
dilutions, followed by herbicides and then
insecticides, with very similar profiles in all cell
types. Despite its relatively benign reputation,
Roundup was among the most toxic herbicides and
insecticides tested. Most importantly, 8
formulations out of 9 were up to one thousand times
more toxic than their active principles. Our results
challenge the relevance of the acceptable daily
intake for pesticides because this norm is
calculated from the toxicity of the active principle
alone. Chronic tests on pesticides may not reflect
relevant environmental exposures if only one
ingredient of these mixtures is tested alone. Adjuvants 4.
Mesnage,
Robin, Bernay, Benoit, and Seralini, Gilles-Eric,
Ethoxylated Adjuvants of Glyphosate-Based
Herbicides are Active Principals of Human Cell
Toxicity, Toxicology
313, nos. 2 3 (November 2013). Published
online September21, 2012 Abstract: Pesticides are always used
in formulations as mixtures of an active principle
with adjuvants. Glyphosate, the active ingredient of
the major pesticide in the world, is an herbicide
supposed to be specific on plant metabolism. Its
adjuvants are generally considered as inert
diluents. Since side effects for all these compounds
have been claimed, we studied potential active
principles for toxicity on human cells for 9
glyphosate-based formulations. For this we detailed
their compositions and toxicities, and as controls
we used a major adjuvant (the
polyethoxylatedtallowamine POE-15), glyphosate
alone, and a total formulation without glyphosate.
This was performed after 24h exposures on hepatic
(HepG2), embryonic (HEK293) and placental (JEG3)
cell lines. We measured mitochondrial activities,
membrane degradations, and caspases 3/7 activities.
The compositions in adjuvants were analyzed by mass
spectrometry. Here we demonstrate that all
formulations are more toxic than glyphosate, and we
separated experimentally three groups of
formulations differentially toxic according to their
concentrations in ethoxylated adjuvants. Among them,
POE-15 clearly appears to be the most toxic
principle against human cells, even if others are
not excluded. It begins to be active with negative
dose-dependent effects on cellular respiration and
membrane integrity between 1 and 3ppm, at
environmental/occupational doses. We demonstrate in
addition that POE-15 induces necrosis when its first
micellization process occurs, by contrast to
glyphosate which is known to promote endocrine
disrupting effects after entering cells. Altogether,
these results challenge the establishment of
guidance values such as the acceptable daily intake
of glyphosate, when these are mostly based on a long
term in vivo test of glyphosate alone. Since
pesticides are always used with adjuvants that could
change their toxicity, the necessity to assess their
whole formulations as mixtures becomes obvious. This
challenges the concept of active principle of
pesticides for non-target species. Metabolites 5.
Bonnet, J.L., F.
Bonnemoy, M. Dusser, and J. Bohatier(2007). Assessment of the
potential toxicity of herbicides and their
degradation products to nontarget cells using two
microorganisms, the bacteria Vibrio fischeri and the
ciliate Tetrahymena pyriformis. Abstract: The potential toxicity of
several herbicides-alachlor, diuron and its photo
and biotransformation products, glyphosate and its
metabolite aminomethyl phosphonic acid (AMPA)-to
nontarget cells was assessed using two
microorganisms frequently used in ecotoxicology,
Vibrio fischeri and Tetrahymena pyriformis. Toxicity
assays involved the Microtox test, the T. pyriformis
population growth impairment test employing three
different processes (flasks, tubes, microplates),
and the T. pyriformis nonspecific esterase
activities test. Several IC(50)
or EC(50) values are reported for each molecule.
Alachlor exerted a toxic effect on the two nontarget
cells used. The results for diuron and its photo and
biotransformation products indicated that most of
the metabolites presented nontarget toxicity higher
than that of diuron. Glyphosate and AMPA had a less
negative effect on T. pyriformis than on V.
fischeri. Nevertheless, in all cases, glyphosate was
found to be more toxic than AMPA. Comparison
analysis of the sensitivity of the different tests
showed that, in general, tests using the eukaryotic
cell (T. pyriformis) were more sensitive than test
using the prokaryotic cell (V. fischeri), and that a
population growth criterion is more sensitive than
an enzymatic criterion. The three different
processes that could be used to evaluate effects on
population growth rate were equally sensitive for
the herbicides tested. A significant correlation
between toxicity data and the hydrophobicity of the
chemicals could only be established with the growth
population test. This study demonstrates that it is
essential to assess the toxicity of the metabolites
formed to complete a more comprehensive study of the
environmental impact of a polluting agent. Environmental Toxicology, 22(1): 7891. Dosage 6.
Vandenberg, Laura N. et al., Hormones
and Endocrine-Disrupting Chemicals: Low-Dose Effects
and Nonmonotonic Dose Responses, Endocrine
Reviews 33, no. 3 (June 2012):378-455. Abstract: For decades, studies of
endocrine-disrupting chemicals (EDCs) have
challenged traditional concepts in toxicology, in
particular the dogma of "the dose makes the poison,"
because EDCs can have effects at low doses that are
not predicted by effects at higher doses. Here, we
review two major concepts in EDC studies: low dose
and nonmonotonicity. Low-dose effects were defined
by the National Toxicology Program as those that
occur in the range of human exposures or effects
observed at doses below those used for traditional
toxicological studies. We review the mechanistic
data for low-dose effects and use a
weight-of-evidence approach to analyze five examples
from the EDC literature. Additionally, we explore
nonmonotonic dose-response curves, defined as a
nonlinear relationship between dose and effect where
the slope of the curve changes sign somewhere within
the range of doses examined. We provide a detailed
discussion of the mechanisms responsible for
generating these phenomena, plus hundreds of
examples from the cell culture, animal, and
epidemiology literature. We illustrate that
nonmonotonic responses and low-dose effects are
remarkably common in studies of natural hormones and
EDCs. Whether low doses of EDCs influence certain
human disorders is no longer conjecture, because
epidemiological studies show that environmental
exposures to EDCs are associated with human diseases
and disabilities. We conclude that when nonmonotonic
dose-response curves occur, the effects of low doses
cannot be predicted by the effects observed at high
doses. Thus, fundamental changes in chemical testing
and safety determination are needed to protect human
health. Testing
Practices 7.
Bergman,Ake,Heinde,
Jerrold J., Jobling , Susan, Kidd, Karen A.,
Zoeller, R. Thomas, State of the Science of
Endocrine Disrupting Chemicals, Inter-Organisation
Programme for the Sound Management of Chemicals
(IOMC), with The
Participating Organisations FAO, ILO, UNDP, UNEP,
UNIDO, UNITAR, WHO, World Bank and OECD, 2012, Excerpt: Since there are data from
epidemiological studies showing associations between
human disease end-points and EDC exposures, it is
likely that endocrine diseases and disorders are
occurring at current exposure levels. Put another
way, this means that there are situations in which
individually safe exposures of EDCs have reached a
collectively harmful level or in which levels
thought to be safe are not so. When chemicals are
tested for endocrine disrupting activity under
specific validated Guideline studies, it is
customary to examine three doses to determine a
level not apparently associated with observable
effects. This level, termed the
no-observed-adverse-effect level, is then divided by
a so-called safety or uncertainty factor (of 100,
for example) to extrapolate to levels expected to be
safe for humans or wildlife. The doses declared safe
are not actually tested, nor are the mixtures. These
studies also assume that there is a threshold for
EDC effects, that there will be no effects at low
doses and that the doseresponse curve rises with
increasing dose. As noted above, there is no
threshold for EDC effects due to the presence of
active hormone pathways, and EDCs are likely to have
effects at low doses. Consequently, their
doseresponse curves will not necessarily rise in
proportion to dose. Regulatory guideline studies
also focus on histopathology and organ and body
weights as the end-points. As noted above, EDCs can
cause many diseases and affect many disease
end-points that are not currently assessed in
regulatory studies. Also, risk assessment approaches
do not always assess toxicity during development,
which is the most sensitive window for EDC action,
and also do not follow the animals for their
lifetime, which is needed to assess resulting
diseases. 2. Toxicity
Impact on Animal/Human Health Oxidative
Stress / Cell Damage 8.
Cattani, Daiane et al.,
Mechanisms Underlying the Neurotoxicity Induced by
Glyphosate-Based Herbicide in Immature Rat
Hippocampus: Involvement of Glutamate
Excitotoxicity, Toxicology 320
(March 2014): 34-45. Abstract: Previous studies
demonstrate that glyphosate exposure is associated
with oxidative damage and neurotoxicity. Therefore,
the mechanism of glyphosate-induced neurotoxic
effects needs to be determined. The aim of this
study was to investigate whether Roundup() (a
glyphosate-based herbicide) leads to neurotoxicity
in hippocampus of immature rats following acute
(30min) and chronic (pregnancy and lactation)
pesticide exposure. Maternal exposure to pesticide
was undertaken by treating dams orally with 1% Roundup() (0.38% glyphosate)
during pregnancy and lactation (till 15-day-old).
Hippocampal slices from 15 day old rats were acutely
exposed to Roundup()
(0.00005 to 0.1%) during 30min and experiments were
carried out to determine whether glyphosate affects
(45)Ca(2+) influx and cell viability. Moreover, we
investigated the pesticide effects on oxidative
stress parameters, (14)C-α-methyl-amino-isobutyric
acid
((14)C-MeAIB) accumulation, as well as glutamate
uptake, release and metabolism. Results showed that
acute exposure to Roundup()
(30min) increases (45)Ca(2+) influx by activating
NMDA receptors and voltage-dependent Ca(2+)
channels, leading to oxidative stress and neural
cell death. The mechanisms underlying Roundup()-induced
neurotoxicity also involve the activation of CaMKII
and ERK. Moreover, acute exposure to Roundup() increased
(3)H-glutamate released into the synaptic cleft,
decreased GSH content and increased the
lipoperoxidation, characterizing excitotoxicity and
oxidative damage. We also observed that both acute
and chronic exposure to Roundup()
decreased (3)H-glutamate uptake and metabolism,
while induced (45)Ca(2+) uptake and (14)C-MeAIB
accumulation in immature rat hippocampus. Taken
together, these results demonstrated that Roundup() might lead to
excessive extracellular glutamate levels and
consequently to glutamate excitotoxicity and
oxidative stress in rat hippocampus. 9.
Lushchak, Oleh V. et al., Low
Toxic Herbicide Roundup Induces Mild Oxidative
Stress in Goldfish Tissues Chemosphere 76
no.7 (2009): 932-37 Abstract: The formulation of Roundup
consists of the herbicide glyphosate as the active
ingredient with polyethoxylene amine added as a
surfactant. The acute toxicity of Roundup
(particularly of glyphosate) to animals is
considered to be low according to the World Health
Organization, but the extensive use of Roundup may
still cause environmental problems with negative
impact on wildlife, particularly in an aquatic
environment where chemicals may persist for a long
time. Therefore, we studied the effects of Roundup
on markers of oxidative stress and antioxidant
defense in goldfish, Carassiusauratus. 10. El-Shenawy,
Nahia
S.,
Oxidative Stress Responses of Rats Exposed to
Roundup and Its Active Ingredient Glyphosate, Environmental
Toxicology and Pharmacology 28, no.3 (November 2009):
379-85 Abstract: Glyphosate is the active
ingredient and polyoxyethyleneamine, the major
component, is the surfactant present in the
herbicide Roundup formulation. The objective of this
study was to analyze potential cytotoxicity of the
Roundup and its fundamental substance (glyphosate).
Albino male rats were intraperitoneally treated with
sub-lethal concentration of Roundup (269.9mg/kg) or
glyphosate (134.95mg/kg) each 2 days, during 2
weeks. Hepatotoxicity was monitored by quantitative
analysis of the serum alanine aminotransferase
(ALT), aspartate aminotransferase (AST), alkaline
phosphatase (ALP) activities, total protein,
albumin, triglyceride and cholesterol. Creatinine
and urea were used as the biochemical markers of
kidney damages. The second aim of this study to
investigate how glyphosate alone or included in
herbicide Roundup affected hepatic reduced
glutathione (GSH) and lipid peroxidation (LPO)
levels of animals as an index of antioxidant status
and oxidative stress, respectively, as well as the
serum nitric oxide (NO) and alpha tumour necrosis
factor (TNF-α) were measured. Treatment of animals
with Roundup induced the leakage of hepatic
intracellular enzymes, ALT, AST and ALP suggesting
irreversible damage in hepatocytes starting from the
first week. It was found that the effects were
different on the enzymes in Roundup and
glyphosate-treated groups. Significant
time-dependent depletion of GSH levels and induction
of oxidative stress in liver by the elevated levels
of LPO, further confirmed the potential of Roundup
to induce oxidative stress in hepatic tissue.
However, glyphosate caused significant increases in
NO levels more than Roundup after 2 weeks of
treatment. Both treatments increased the level of
TNF-α by the same manner. The results suggest that
excessive antioxidant disruptor and oxidative stress
is induced with Roundup than glyphosate. 11. Richard,
S., Moslemi, S. et al. 2005.
Differential effects of glyphosate and roundup on
human placental cells and aromatase. Environ Health
Perspect 113(6): 716720. Abstract: Roundup is a
glyphosate-based herbicide used worldwide, including
on most genetically modified plants that have been
designed to tolerate it. Its residues may thus enter
the food chain, and glyphosate is found as a
contaminant in rivers. Some agricultural workers
using glyphosate have pregnancy problems, but its
mechanism of action in mammals is questioned. Here
we show that glyphosate is toxic to human placental
JEG3 cells within 18 hr with concentrations lower
than those found with agricultural use, and this
effect increases with concentration and time or in
the presence of Roundup adjuvants. Surprisingly,
Roundup is always more toxic than its active
ingredient. We tested the effects of glyphosate and
Roundup at lower nontoxic concentrations on
aromatase, the enzyme responsible for estrogen
synthesis. The glyphosate-based herbicide disrupts
aromatase activity and mRNA levels and interacts
with the active site of the purified enzyme, but the
effects of glyphosate are facilitated by the Roundup
formulation in microsomes or in cell culture. We
conclude that endocrine and toxic effects of
Roundup, not just glyphosate, can be observed in
mammals. We suggest that the presence of Roundup
adjuvants enhances glyphosate bioavailability and/or
bioaccumulation. 12. Mesnage, Robin, Bernay,
Benoit, and Seralini, Gilles-Eric, Ethoxylated
Adjuvants of Glyphosate-Based Herbicides are Active
Principals of Human Cell Toxicity, Toxicology 313,
nos. 2 3 (November 2013). Published
online September21, 2012 Abstract: Pesticides are always used
in formulations as mixtures of an active principle
with adjuvants. Glyphosate, the active ingredient of
the major pesticide in the world, is an herbicide
supposed to be specific on plant metabolism. Its
adjuvants are generally considered as inert
diluents. Since side effects for all these compounds
have been claimed, we studied potential active
principles for toxicity on human cells for 9
glyphosate-based formulations. For this we detailed
their compositions and toxicities, and as controls
we used a major adjuvant (the
polyethoxylatedtallowamine POE-15), glyphosate
alone, and a total formulation without glyphosate.
This was performed after 24h exposures on hepatic
(HepG2), embryonic (HEK293) and placental (JEG3)
cell lines. We measured mitochondrial activities,
membrane degradations, and caspases 3/7 activities.
The compositions in adjuvants were analyzed by mass
spectrometry. Here we demonstrate that all
formulations are more toxic than glyphosate, and we
separated experimentally three groups of
formulations differentially toxic according to their
concentrations in ethoxylated adjuvants. Among them,
POE-15 clearly appears to be the most toxic
principle against human cells, even if others are
not excluded. It begins to be active with negative
dose-dependent effects on cellular respiration and
membrane integrity between 1 and 3ppm, at
environmental/occupational doses. We demonstrate in
addition that POE-15 induces necrosis when its first
micellization process occurs, by contrast to
glyphosate which is known to promote endocrine
disrupting effects after entering cells. Altogether,
these results challenge the establishment of
guidance values such as the acceptable daily intake
of glyphosate, when these are mostly based on a long
term in vivo test of glyphosate alone. Since
pesticides are always used with adjuvants that could
change their toxicity, the necessity to assess their
whole formulations as mixtures becomes obvious. This
challenges the concept of active principle of
pesticides for non-target species. 13. Marc, Julie.,Mulner-Lorillon, O.,
Bell, R. 2004. Glyphosate-based pesticides affect
cell cycle regulation. Biology of the
Cell 96: 245249. Abstract: Cell-cycle dysregulation is
a hallmark of tumor cells and human cancers. Failure
in the cell-cycle checkpoints leads to genomic
instability and subsequent development of cancers
from the initial affected cell. A worldwide used
product Roundup 3plus, based on glyphosate as the
active herbicide, was suggested to be of human
health concern since it induced cell cycle
dysfunction as judged from analysis of the first
cell division of sea urchin embryos, a recognized
model for cell cycle studies. Several
glyphosate-based pesticides from different
manufacturers were assayed in comparison with
Roundup 3plus for their ability to interfere with
the cell cycle regulation. All the tested products,
Amega, Cargly, Cosmic, and Roundup Biovert induced
cell cycle dysfunction. The threshold concentration
for induction of cell cycle dysfunction was
evaluated for each product and suggests high risk by
inhalation for people in the vicinity of the
pesticide handling sprayed at 500 to 4000 times
higher dose than the cell-cycle adverse
concentration. 14. Chaufan,
G. et al
2014, Glyphosate commercial formulation causes
cytotoxicty, oxidative effects, and apoptosis on
human cells: differences with its active
ingredient,
Int. J. Toxicol 33(1) 29-38. Abstract: In the present study, the
effects on oxidative balance and cellular end points
of glyphosate, aminomethylphosphonic acid (AMPA),
and a glyphosate formulation (G formulation) were
examined in HepG2 cell line, at dilution levels far
below agricultural recommendations. Our results show
that G formulation had toxic effects while no
effects were found with acid glyphosate and AMPA
treatments. Glyphosate formulation exposure produced
an increase in reactive oxygen species,
nitrotyrosine formation, superoxide dismutase
activity, and glutathione (GSH) levels, while no
effects were observed for catalase and
GSH-S-transferase activities. Also, G formulation
triggered caspase 3/7 activation and hence induced
apoptosis pathway in this cell line.
Aminomethylphosphonic acid exposure produced an
increase in GSH levels while no differences were
observed in other antioxidant parameters. No effects
were observed when the cells were exposed to acid
glyphosate. These results confirm that G
formulations have adjuvants working together with
the active ingredient and causing toxic effects that
are not seen with acid glyphosate. 15. Vivancos,
P.D.; Driscoll, S.P.; Bulman, C.A.; Ying, L.;
Emami, K.; Treumann, A.; Mauve, C.; Noctor, G.;
Foyer, C.H.
Perturbations of amino acid metabolism associated
with glyphosate-dependent inhibition of shikimic acid
metabolism affect cellular redox homeostasis
and alter the abundance of proteins involved in
photosynthesis and photorespiration. Plant
Physiol. 2011, 157, 256268. Abstract: The herbicide glyphosate
inhibits the shikimate pathway of the synthesis of
amino acids such as phenylalanine, tyrosine, and
tryptophan. However, much uncertainty remains
concerning precisely how glyphosate kills plants or
affects cellular redox homeostasis and related
processes in glyphosate-sensitive and
glyphosate-resistant crop plants. To address this
issue, we performed an integrated study of
photosynthesis, leaf proteomes, amino acid profiles,
and redox profiles in the glyphosate-sensitive
soybean (Glycine max) genotype PAN809 and
glyphosate-resistant Roundup Ready Soybean (RRS).
RRS leaves accumulated much more glyphosate than the
sensitive line but showed relatively few changes in
amino acid metabolism. Photosynthesis was unaffected
by glyphosate in RRS leaves, but decreased abundance
of photosynthesis/photorespiratory pathway proteins
was observed together with oxidation of major redox
pools. While treatment of a sensitive genotype with
glyphosate rapidly inhibited photosynthesis and
triggered the appearance of a nitrogen-rich amino
acid profile, there was no evidence of oxidation of
the redox pools. There was, however, an increase in
starvation-associated and defense proteins. We
conclude that glyphosate-dependent inhibition of
soybean leaf metabolism leads to the induction of
defense proteins without sustained oxidation.
Conversely, the accumulation of high levels of
glyphosate in RRS enhances cellular oxidation,
possibly through mechanisms involving stimulation of
the photorespiratory pathway. 16. Belle, R, Le
Bouffant R, Morales J, Cosson B, Cormier P, Mulner-Lorillon
O.,
Sea urchin embryo, DNA-damaged cell cycle
checkpoint and the mechanisms initiating cancer
development J.
Soc. Biology 2007;201(3):317-27. Abstract: Cell division
is an essential process for heredity, maintenance
and evolution of the whole living kingdom. Sea
urchin early development represents an excellent
experimental model for the analysis of cell cycle
checkpoint mechanisms since embryonic cells contain
a functional DNA-damage checkpoint and since the
whole sea urchin genome is sequenced. The
DNA-damaged checkpoint is responsible for an arrest
in the cell cycle when DNA is damaged or incorrectly
replicated, for activation of the DNA repair
mechanism, and for commitment to cell death by
apoptosis in the case of failure to repair. New
insights in cancer biology lead to two fundamental
concepts about the very first origin of
cancerogenesis. Cancers result from dysfunction of
DNA-damaged checkpoints and cancers appear as a
result of normal stem cell (NCS) transformation into
a cancer stem cell (CSC). The second aspect suggests
a new definition of "cancer", since CSC can be
detected well before any clinical evidence. Since
early development starts from the zygote, which is a
primary stem cell, sea urchin early development
allows analysis of the early steps of the
cancerization process. Although sea urchins do not
develop cancers, the model is alternative and
complementary to stem cells which are not easy to
isolate, do not divide in a short time and do not
divide synchronously. In the field of toxicology and
incidence on human health, the sea urchin
experimental model allows assessment of cancer risk
from single or combined molecules long before any
epidemiologic evidence is available. Sea urchin
embryos were used to test the worldwide used
pesticide Roundup that contains glyphosate as the
active herbicide agent; it was shown to activate the
DNA-damage checkpoint of the first cell cycle of
development. The model therefore allows considerable
increase in risk evaluation of new products in the
field of cancer and offers a tool for the discovery
of molecular markers for early diagnostic in cancer
biology. Prevention and early diagnosis are two
decisive elements of human cancer therapy. 17. Hedberg, D.,
and M. Wallin(2010).
Effects of Roundup and glyphosate formulations on
intracellular transport, microtubules and actin
filaments in Xenopus laevis melanophores. Abstract: Glyphosate containing
herbicides, such as Roundup, are commonly used and
generally considered to be safe. However, some toxic
effects are found on amphibians in vivo and human
and mouse cells in vitro. In this study the effects
of Roundup, glyphosate, glyphosateisopropylamine and
isopropylamine were studied on intracellular
transport by measuring aggregation capacity in
Xenopus laevis melanophores. The chemicals inhibited
retrograde transport of melanosomes in the range of
0.5-5mM. Cellular morphology and localization of
microtubules and actin filaments were affected as
determined by immunocytochemistry. Both glyphosate
and Roundup decreased pH in the media. Acidic pH
inhibited melanosome transport and altered
microtubule and actin morphology in the absence of
chemicals, while transport inhibiting concentrations
of glyphosate, Roundup and glyphosateisopropylamine
disassembled both microtubules and actin filaments.
At physiological pH the effects of Roundup decreased
whereas glyphosate failed to inhibit transport.
Physiological pH decreases glyphosate lipophilicity
and its diffusion into the cytoplasm. The Roundup
formulation contains surfactants, such as POEA
(polyetylated tallow amine) that increases membrane
permeability allowing cellular uptake at
physiological pH. Our results show that the effects
of glyphosate containing compounds are pH-dependent
and that they inhibit intracellular transport
through disassembly of the cytoskeleton possibly by
interfering with intracellular Ca(2+)-balance. Toxicology.in
Vitro
24: 795802. Breaks in DNA
Strands 18. Gasnier,
C.;
Dumont, C.; Benachour, N.; Clair, E.; Chagnon,
M.C.; Sralini, G.E.
Glyphosate-based herbicides are toxic and endocrine
disruptors in human cell lines. Toxicology 2009,
262, 184191. Abstract: Glyphosate-based herbicides
are the most widely used across the world; they are
commercialized in different formulations. Their
residues are frequent pollutants in the environment.
In addition, these herbicides are spread on most
eaten transgenic plants, modified to tolerate high
levels of these compounds in their cells. Up to 400
ppm of their residues are accepted in some feed. We
exposed human liver HepG2 cells, a well-known model
to study xenobiotic toxicity, to four different
formulations and to glyphosate, which is usually
tested alone in chronic in vivo regulatory studies.
We measured cytotoxicity with three assays (Alamar
Blue, MTT, ToxiLight), plus genotoxicity (comet
assay), anti-estrogenic (on ERalpha, ERbeta) and
anti-androgenic effects (on AR) using gene reporter
tests. We also checked androgen to estrogen
conversion by aromatase activity and mRNA. All
parameters were disrupted at sub-agricultural doses
with all formulations within 24h. These effects were
more dependent on the formulation than on the
glyphosate concentration. First, we observed a human
cell endocrine disruption from 0.5 ppm on the
androgen receptor in MDA-MB453-kb2 cells for the
most active formulation (R400), then from 2 ppm the
transcriptional activities on both estrogen
receptors were also inhibited on HepG2. Aromatase
transcription and activity were disrupted from 10
ppm. Cytotoxic effects started at 10 ppm with Alamar
Blue assay (the most sensitive), and DNA damages at
5 ppm. A real cell impact of glyphosate-based
herbicides residues in food, feed or in the
environment has thus to be considered, and their
classifications as carcinogens/mutagens/reprotoxics
is discussed. 19. Bagchi D, M.
Bagchi, E.A. Hassoun, and S.J. Stohs(1995). In
vitro and in vivo generation of reactive oxygen
species, DNA damage and lactate dehydrogenase
leakage by selected pesticides. Abstract: Reactive oxygen species may
be involved in the toxicity of various pesticides
and we have, therefore, examined the in vivo effects
of structurally dissimilar polyhalogenated cyclic
hydrocarbons (PCH), such as endrin and chlordane,
chlorinated acetamide herbicides (CAH), such as
alachlor, and organophosphate pesticides (OPS), such
as chlorpyrifos and fenthion, on the production of
hepatic and brain lipid peroxidation and DNA-single
strand breaks (SSB), two indices of oxidative stress
and oxidative tissue damage. The selected pesticides
were administered p.o. to female Sprague-Dawley rats
in two 0.25 LD50 doses at 0 h and 21 h and killed at
24 h. In a parallel set of experiments, we have
determined the in vitro effects of these pesticides
on the DNA-SSB and enhanced lactate dehydrogenase
leakage (LDH) from neuroactive PC-12 cells in
culture. In vitro production of reactive oxygen
species by these pesticides was also assessed by
determining the enhanced chemiluminescence responses
of hepatic and brain homogenates. Following
treatment of rats with endrin, chlordane, alachlor,
chlorpyrifos and fenthion, increases of 2.8-, 3.0-,
4.2-, 4.3- and 4.8-fold were observed in hepatic
lipid peroxidation, respectively, while at these
same doses, increases in lipid peroxidation of 2.4-,
2.1-, 3.6-, 4.6- and 5.3-fold, respectively, were
observed in brain homogenates. Increases of 4.4-,
3.9-, 1.6-, 3.0- and 3.5-fold were observed in
hepatic DNA-SSB following treatment of the rats with
endrin, chlordane, alachlor, chlorpyrifos and
fenthion, respectively, while at these same doses,
increases of 1.9-, 1.7-, 2.2-, 1.4-, 1.4-fold,
respectively, were observed in brain nuclear
DNA-SSB. Following in vitro incubation of hepatic
and brain tissues with 1 nmol/ml of each of the five
pesticides, maximum increases in chemiluminescence
occurred within 4-7 min of incubation and persisted
for over 10 min. Increases of 3.0-, 2.7-, 3.6-, 4.9-
and 4.4-fold were observed in chemiluminescence
following in vitro incubation of the liver
homogenates with endrin, chlordane, alachlor,
chlorpyrifos and fenthion, respectively, while
increases of 1.7-, 1.8-, 2.0-, 3.4- and 3.7-fold,
respectively, were observed in the brain
homogenates. Increases of 2.2-, 2.3-, 2.9-, 2.9- and
3.4-fold were observed in the chemiluminescence
responses in the liver homogenates of the animals
treated with endrin, chlordane, alachlor,
chlorpyrifos and fenthion, respectively, while
increases of 1.8-, 2.0-, 3.2-, 2.9- and 2.4-fold,
respectively, were observed in the brain
homogenates. Cultured neuroactive PC-12 cells were
incubated with the pesticides and the release of the
enzyme lactate dehydrogenase (LDH) into the media as
an indicator of cellular damage and cytotoxicity was
examined. Maximal release of LDH from cultured PC-12
cells was observed at 100 nM concentrations of the
pesticides. Increases of 2.3-, 2.5-, 2.8-, 3.1 and
3.4-fold were observed in LDH leakage following
incubation of the PC-12 cells with endrin,
chlordane, alachlor, chlorpyrifos and fenthion,
respectively. Following incubation of the cultured
PC-12 cells with 100 nM concentrations of these same
pesticides, increases in DNA-SSB of 2.5-, 2.2-,
2.1-, 2.4- and 2.5-fold, respectively, were
observed. The results clearly demonstrate that these
different classes of pesticides induce production of
reactive oxygen species and oxidative tissue damage
which may contribute to the toxic manifestations of
these xenobiotics. Reactive oxygen species may serve
as common mediators of programmed cell death
(apoptosis) in response to many toxicants and
pathological conditions. Toxicology,
104(1-3):129140. Microbiome 20. Anthony Samsel and Stephanie
Seneff,
Glyphosate, Pathways to Modern Diseases II: Celiac
Sprue and Gluten Intolerance, Interdisciplinary
Toxicology 6, no.4 (2013): 159 84. Abstract: Celiac disease, and, more
generally, gluten intolerance, is a growing problem
worldwide, but especially in North America and
Europe, where an estimated 5% of the population now
suffers from it. Symptoms include nausea, diarrhea,
skin rashes, macrocytic anemia and depression. It is
a multifactorial disease associated with numerous
nutritional deficiencies as well as reproductive
issues and increased risk to thyroid disease, kidney
failure and cancer. Here, we propose that
glyphosate, the active ingredient in the herbicide,
Roundup(), is the most
important causal factor in this epidemic. Fish
exposed to glyphosate develop digestive problems
that are reminiscent of celiac disease. Celiac
disease is associated with imbalances in gut
bacteria that can be fully explained by the known
effects of glyphosate on gut bacteria.
Characteristics of celiac disease point to
impairment in many cytochrome P450 enzymes, which
are involved with detoxifying environmental toxins,
activating vitamin D3, catabolizing vitamin A, and
maintaining bile acid production and sulfate
supplies to the gut. Glyphosate is known to inhibit
cytochrome P450 enzymes. Deficiencies in iron,
cobalt, molybdenum, copper and other rare metals
associated with celiac disease can be attributed to
glyphosate's strong ability to chelate these
elements. Deficiencies in tryptophan, tyrosine,
methionine and selenomethionine associated with
celiac disease match glyphosate's known depletion of
these amino acids. Celiac disease patients have an
increased risk to non-Hodgkin's lymphoma, which has
also been implicated in glyphosate exposure.
Reproductive issues associated with celiac disease,
such as infertility, miscarriages, and birth
defects, can also be explained by glyphosate.
Glyphosate residues in wheat and other crops are
likely increasing recently due to the growing
practice of crop desiccation just prior to the
harvest. We argue that the practice of "ripening"
sugar cane with glyphosate may explain the recent
surge in kidney failure among agricultural workers
in Central America. We conclude with a plea to
governments to reconsider policies regarding the
safety of glyphosate residues in foods. 21. Shehata, Awad Ali, Schrodl,
Wieland, Aldin, Alaa A. Hafex, Hafex M. and
Kruger, Monika, The Effect of
Glyphosate on Potential Pathogens and Beneficial
Members of Poultry Microbiota in Vitro, Current
Microbiology 66, no 4 (2013): 350-58. Abstract: The use of glyphosate
modifies the environment which stresses the living
microorganisms. The aim of the present study was to
determine the real impact of glyphosate on potential
pathogens and beneficial members of poultry
microbiota in vitro. The presented results evidence
that the highly pathogenic bacteria as Salmonella
Entritidis, Salmonella Gallinarum, Salmonella
Typhimurium, Clostridium perfringens and Clostridium
botulinum are highly resistant to glyphosate.
However, most of beneficial bacteria as Enterococcus
faecalis, Enterococcus faecium, Bacillus badius,
Bifidobacteriumadolescentis and Lactobacillus spp.
were found to be moderate to highly susceptible.
Also Campylobacter spp. were
found to be susceptible to glyphosate. A reduction
of beneficial bacteria in the gastrointestinal tract
microbiota by ingestion of glyphosate could disturb
the normal gut bacterial community. Also, the
toxicity of glyphosate to the most prevalent
Enterococcus spp. could be a significant
predisposing factor that is associated with the
increase in C. botulinum-mediated diseases by
suppressing the antagonistic effect of these
bacteria on clostridia. 22. Samsel,
Anthony and Seneff, Stepanie, Glyphosates Suppression of Cytochrome
P450 Enzymes and Amino Acid Biosynthesis by the Gut
Microbiome: Pathways to Modern Diseases, Entropy 15, no.
4 (2013): 1416-63. Abstract:
Glyphosate,
the active ingredient in Roundup, is the most
popular herbicide used worldwide. The industry
asserts it is minimally toxic to humans, but here we
argue otherwise. Residues are found in the main
foods of the Western diet, comprised primarily of
sugar, corn, soy and wheat. Glyphosate's inhibition
of cytochrome P450 (CYP) enzymes is an overlooked
component of its toxicity to mammals. CYP enzymes
play crucial roles in biology, one of which is to
detoxify xenobiotics. Thus, glyphosate enhances the
damaging effects of other food borne chemical
residues and environmental toxins. Negative impact
on the body is insidious and manifests slowly over
time as inflammation damages cellular systems
throughout the body. Here, we show how interference
with CYP enzymes acts synergistically with
disruption of the biosynthesis of aromatic amino
acids by gut bacteria, as well as impairment in
serum sulfate transport. Consequences are most of
the diseases and conditions associated with a
Western diet, which include gastrointestinal
disorders, obesity, diabetes, heart disease,
depression, autism, infertility, cancer and
Alzheimers disease. We explain the documented
effects of glyphosate and its ability to induce
disease, and we show that glyphosate is the
textbook example of exogenous semiotic entropy:
the disruption of homeostasis by environmental
toxins. 23. Seneff, S., Swanson, N. and
Li, C.
(2015) Aluminum and Glyphosate Can Synergistically
Induce Pineal Gland Pathology: Connection to Gut
Dysbiosis and Neurological Disease. Agricultural
Sciences, 6, 42-70. Abstract:
Many
neurological diseases, including autism, depression,
dementia, anxiety disorder and Parkinsons disease,
are associated with abnormal sleep patterns, which
are directly linked to pineal gland dysfunction. The
pineal gland is highly susceptible to environmental
toxicants. Two pervasive substances in modern
industrialized nations are aluminum and glyphosate,
the active ingredient in the herbicide, Roundup?. In this paper, we show how
these two toxicants work synergistically to induce
neurological damage. Glyphosate disrupts gut
bacteria, leading to an overgrowth of Clostridium
difficile. Its toxic product, p-cresol, is linked to
autism in both human and mouse models. p-Cresol enhances uptake of
aluminum via transferrin. Anemia, a result of both
aluminum disruption of heme and impaired heme
synthesis by glyphosate, leads to hypoxia, which
induces increased pineal gland transferrin
synthesis. Premature birth is associated with
hypoxic stress and with substantial increased risk
to the subsequent development of autism, linking
hypoxia to autism. Glyphosate chelates aluminum,
allowing ingested aluminum to bypass the gut
barrier. This leads to anemia-induced hypoxia,
promoting neurotoxicity and damaging the pineal
gland. Both glyphosate and aluminum disrupt
cytochrome P450 enzymes, which are involved in
melatonin metabolism. Furthermore, melatonin is
derived from tryptophan, whose synthesis in plants
and microbes is blocked by glyphosate. We also
demonstrate a plausible role for vitamin D3
dysbiosis in impaired gut function and impaired
serotonin synthesis. This paper proposes that
impaired sulfate supply to the brain mediates the
damage induced by the synergistic action of aluminum
and glyphosate on the pineal gland and related
midbrain nuclei. Metabolic
Pathway-Endocrine Disruption 24. Vandenberg, Laura N. et al., Hormones and
Endocrine-Disrupting Chemicals: Low-Dose Effects and
Nonmonotonic Dose Responses, Endocrine
Reviews 33, no. 3 (June 2012):378-455. Abstract: For decades, studies of
endocrine-disrupting chemicals (EDCs) have
challenged traditional concepts in toxicology, in
particular the dogma of "the dose makes the poison,"
because EDCs can have effects at low doses that are
not predicted by effects at higher doses. Here, we
review two major concepts in EDC studies: low dose
and nonmonotonicity. Low-dose effects were defined
by the National Toxicology Program as those that
occur in the range of human exposures or effects
observed at doses below those used for traditional
toxicological studies. We review the mechanistic
data for low-dose effects and use a
weight-of-evidence approach to analyze five examples
from the EDC literature. Additionally, we explore
nonmonotonic dose-response curves, defined as a
nonlinear relationship between dose and effect where
the slope of the curve changes sign somewhere within
the range of doses examined. We provide a detailed
discussion of the mechanisms responsible for
generating these phenomena, plus hundreds of
examples from the cell culture, animal, and
epidemiology literature. We illustrate that
nonmonotonic responses and low-dose effects are
remarkably common in studies of natural hormones and
EDCs. Whether low doses of EDCs influence certain
human disorders is no longer conjecture, because
epidemiological studies show that environmental
exposures to EDCs are associated with human diseases
and disabilities. We conclude that when nonmonotonic
dose-response curves occur, the effects of low doses
cannot be predicted by the effects observed at high
doses. Thus, fundamental changes in chemical testing
and safety determination are needed to protect human
health. 25. Peraldi,
P.;
Hotamisligil, G.S.; Buurman, W.A.; White, M.F.;
Spiegelman, B.M.Tumor
necrosis factor (TNF)-alpha inhibits insulin
signaling through stimulation of the p55 TNF
receptor and activation of sphingomyelinase. J.
Biol. Chem. 1996, 271,
1301813022. Abstract: Tumor necrosis factor
(TNF)-alpha plays a central role in the state of
insulin resistance associated with obesity. It has
previously been shown that one important mechanism
by which TNF-alpha interferes with insulin signaling
is through the serine phosphorylation of insulin
receptor substrate-1 (IRS-1), which can then
function as an inhibitor of the tyrosine kinase
activity of the insulin receptor (IR). However, the
receptors and the signaling pathway used by
TNF-alpha that mediate
the inhibition of IR activity are unknown. We show
here that human TNF-alpha, which binds only to the
murine p55 TNF receptor (TNFR), is as effective at
inhibiting insulin-dependent tyrosine
phosphorylation of IR and IRS-1 in adipocytes and
myeloid 32D cells as murine TNF-alpha, which binds
to both p55 TNFR and p75 TNFR. Likewise, antibodies
that are specific agonists for p55 TNFR or p75 TNFR
demonstrate that stimulation of p55 TNFR is
sufficient to inhibit insulin signaling, though a
small effect can also be seen with antibodies to p75
TNFR. Exogenous sphingomyelinase and ceramides,
known to be formed by activation of p55 TNFR,
inhibit IR and IRS-1 tyrosine phosphorylation and
convert IRS-1 into an inhibitor of IR tyrosine
kinase in vitro. Myeloid 32D cells expressing IR and
IRS-1 are sensitive to this inhibition, but cells
expressing IR and IRS-2 are resistant, pointing to
an important difference in the biological function
between IRS-1 and IRS-2. These data strongly suggest
that TNF-alpha inhibits insulin signaling via
stimulation of p55 TNFR and sphingomyelinase
activity, which results in the production of an
inhibitory form of IRS-1. Declining Sperm
Count - Testicular Issues (DNA) 26. Romano,
R. M., Romano, M. A. et al. 2010.
Prepubertal exposure to commercial formulation of
the herbicide Glyphosate alters testosterone levels
and testicular morphology. Archives of
Toxicology 84(4): 309317. Abstract: Glyphosate is a herbicide widely used to
kill weeds both in agricultural and non-agricultural
landscapes. Its reproductive toxicity is related to
the inhibition of a StAR protein and an aromatase
enzyme, which causes an in vitro reduction in
testosterone and estradiol synthesis. Studies in
vivo about this herbicide effects in
prepubertalWistar rats reproductive development were
not performed at this moment. Evaluations included
the progression of puberty, body development, the
hormonal production of testosterone, estradiol and
corticosterone, and the morphology of the testis.
Results showed that the herbicide (1) significantly
changed the progression of puberty in a
dose-dependent manner; (2) reduced the testosterone
production, in semineferous tubules' morphology,
decreased significantly the epithelium height (P
< 0.001; control = 85.8 +/- 2.8 microm; 5 mg/kg =
71.9 +/- 5.3 microm; 50 mg/kg = 69.1 +/- 1.7 microm;
250 mg/kg = 65.2 +/- 1.3 microm) and increased the
luminal diameter (P < 0.01; control = 94.0 +/-
5.7 microm; 5 mg/kg = 116.6 +/- 6.6 microm; 50 mg/kg
= 114.3 +/- 3.1 microm; 250 mg/kg = 130.3 +/- 4.8
microm); (4) no difference in tubular diameter was
observed; and (5) relative to the controls, no
differences in serum corticosterone or estradiol
levels were detected, but the concentrations of
testosterone serum were lower in all treated groups
(P < 0.001; control = 154.5 +/- 12.9 ng/dL; 5
mg/kg = 108.6 +/- 19.6 ng/dL; 50 mg/dL = 84.5 +/-
12.2 ng/dL; 250 mg/kg = 76.9 +/- 14.2 ng/dL). These
results suggest that commercial formulation of
glyphosate is a potent endocrine disruptor in vivo,
causing disturbances in the reproductive development
of rats when the exposure was performed during the
puberty period. 27. Clair,
E.; Mesnage, R.; Travert, C.; Sralini, G.E. A
glyphosate-based herbicide induces necrosis and
apoptosis in mature rat testicular cells in
vitro, and testosterone decrease at lower
levels. Toxicol.In Vitro 2012, 26,
269279. Abstract: The major herbicide used
worldwide, Roundup, is a glyphosate-based pesticide
with adjuvants. Glyphosate, its active ingredient in
plants and its main metabolite (AMPA) are among the
first contaminants of surface waters. Roundup is
being used increasingly in particular on genetically
modified plants grown for food and feed that contain
its residues. Here we tested glyphosate and its
formulation on mature rat fresh testicular cells
from 1 to 10000ppm, thus from the range in some
human urine and in environment to agricultural
levels. We show that from 1 to 48h of Roundup
exposure Leydig cells are damaged. Within 24-48h
this formulation is also toxic on the other cells,
mainly by necrosis, by contrast to glyphosate alone
which is essentially toxic on Sertoli cells. Later,
it also induces apoptosis at higher doses in germ
cells and in Sertoli/germ cells co-cultures. At
lower non toxic concentrations of Roundup and
glyphosate (1ppm), the main endocrine disruption is
a testosterone decrease by 35%. The pesticide has
thus an endocrine impact at very low environmental
doses, but only a high contamination appears to
provoke an acute rat testicular toxicity. This does
not anticipate the chronic toxicity
which is insufficiently tested, and only
with glyphosate in regulatory tests. 28. Walsh,
L.P.; McCormick, C.; Martin, C.; Stocco, D.M.
Roundup inhibits steroidogenesis by disrupting
steroidogenic acute regulatory (StAR) protein
expression. Environ. Health Persp. 2000,
108, 769776. Abstract: Recent reports demonstrate
that many currently used pesticides have the
capacity to disrupt reproductive function in
animals. Although this reproductive dysfunction is
typically characterized by alterations in serum
steroid hormone levels, disruptions in
spermatogenesis, and loss of fertility, the
mechanisms involved in pesticide-induced infertility
remain unclear. Because testicular Leydig cells play
a crucial role in male reproductive function by
producing testosterone, we used the mouse MA-10
Leydig tumor cell line to study the molecular events
involved in pesticide-induced alterations in steroid
hormone biosynthesis. We previously showed that the
organochlorine insecticide lindane and the
organophosphate insecticide Dimethoate directly
inhibit steroidogenesis in Leydig cells by
disrupting expression of the steroidogenic acute
regulatory (StAR) protein. StAR protein mediates the
rate-limiting and acutely regulated step in
steroidogenesis, the transfer of cholesterol from
the outer to the inner mitochondrial membrane where
the cytochrome P450 side chain cleavage (P450scc)
enzyme initiates the synthesis of all steroid
hormones. In the present study, we screened eight
currently used pesticide formulations for their
ability to inhibit steroidogenesis, concentrating on
their effects on StAR expression in MA-10 cells. In
addition, we determined the effects of these
compounds on the levels and activities of the
P450scc enzyme (which converts cholesterol to
pregnenolone) and the 3beta-hydroxysteroid
dehydrogenase (3beta-HSD) enzyme (which converts
pregnenolone to progesterone). Of the pesticides
screened, only the pesticide Roundup inhibited
dibutyryl [(Bu)(2)]cAMP-stimulated
progesterone production in MA-10 cells without
causing cellular toxicity. Roundup inhibited
steroidogenesis by disrupting StAR protein
expression, further demonstrating the susceptibility
of StAR to environmental pollutants. 29. Cavalli, V.L., et
al.
Roundup disrupts male reproductive functions by
triggering calcium-mediated cell death in rat testis
and Sertoli cells. Free Radical
Biology and Medicine 65 (2013)335346. Abstract:
Glyphosate
is the primary active constituent of the commercial
pesticide Roundup. The present results show that
acute Roundup exposure at low doses (36 ppm, 0.036
g/L) for 30 min induces oxidative stress and
activates multiple stress-response pathways leading
to Sertoli cell death in prepubertal rat testis. The
pesticide increased intracellular Ca(2+)
concentration by opening L-type voltage-dependent
Ca(2+) channels as well as endoplasmic reticulum IP3
and ryanodine receptors, leading to Ca(2+) overload
within the cells, which set off oxidative stress and
necrotic cell death. Similarly, 30 min incubation of
testis with glyphosate alone (36 ppm) also increased
(45)Ca(2+) uptake. These
events were prevented by the antioxidants Trolox and
ascorbic acid. Activated protein kinase C,
phosphatidylinositol 3-kinase, and the
mitogen-activated protein kinases such as ERK1/2 and
p38MAPK play a role in eliciting Ca(2+) influx and cell death.
Roundup decreased the levels of reduced glutathione
(GSH) and increased the amounts of thiobarbituric
acid-reactive species (TBARS) and protein carbonyls.
Also, exposure to glyphosate-Roundup stimulated the
activity of glutathione peroxidase, glutathione
reductase, glutathione S-transferase,
γ-glutamyltransferase, catalase, superoxide
dismutase, and glucose-6-phosphate dehydrogenase,
supporting downregulated GSH levels. Glyphosate has
been described as an endocrine disruptor affecting
the male reproductive system; however, the molecular
basis of its toxicity remains to be clarified. We
propose that Roundup toxicity, implicated in Ca(2+) overload, cell
signaling misregulation, stress response of the
endoplasmic reticulum, and/or depleted antioxidant
defenses, could contribute to Sertoli cell
disruption in spermatogenesis that could have an
impact on male fertility. Breast Cancer 30. Marc,
Julie,Mulner-Lorillon,
Odile, and Belle, Robert Glyphosate-Based
Pesticides Affect Cell Cycle Regulation, Biology of the
Cell 96, no. 3 (April 2004): 245-49. Abstract: Cell-cycle dysregulation is
a hallmark of tumor cells and human cancers. Failure
in the cell-cycle checkpoints leads to genomic
instability and subsequent development of cancers
from the initial affected cell. A worldwide used
product Roundup 3plus, based on glyphosate as the
active herbicide, was suggested to be of human
health concern since it induced cell cycle
dysfunction as judged from analysis of the first
cell division of sea urchin embryos, a recognized
model for cell cycle studies. Several
glyphosate-based pesticides from different
manufacturers were assayed in comparison with
Roundup 3plus for their ability to interfere with
the cell cycle regulation. All the tested products,
Amega, Cargly, Cosmic, and Roundup Biovert induced
cell cycle dysfunction. The threshold concentration
for induction of cell cycle dysfunction was
evaluated for each product and suggests high risk by
inhalation for people in the vicinity of the
pesticide handling sprayed at 500 to 4000 times
higher dose than the cell-cycle adverse
concentration. 31. Hokanson,
R., Fudge, R. et al. 2007.
Alteration of estrogen-regulated gene expression in
human cells induced by the agricultural and
horticultural herbicide glyphosate. Hum ExpToxicol
26(9): 747752. Abstract: Gene expression is altered
in mammalian cells (MCF-7 cells), by exposure to a
variety of chemicals that mimic steroid hormones or
interact with endocrine receptors or their
co-factors. Among those populations chronically
exposed to these endocrine disruptive chemicals are
persons, and their families, who are employed in
agriculture or horticulture, or who use
agricultural/horticultural chemicals. Among the
chemicals most commonly used, both commercially and
in the home, is the herbicide glyphosate. Although
glyphosate is commonly considered to be relatively
non-toxic, we utilized in vitro DNA microarray
analysis of this chemical to evaluate its capacity
to alter the expression of a variety of genes in
human cells. We selected a group of genes,
determined by DNA microarray analysis to be
dysregulated, and used quantitative real-time PCR to
corroborate their altered states of expression. We
discussed the reported function of those genes, with
emphasis on altered physiological states that are
capable of initiating adverse health effects that
might be anticipated if gene expression were
significantly altered in either adults or embryos
exposed in utero. 32. Thongprakaisang,
Siriporn, et al.,
Glyphosate Induces Human Breast Cancer Cells Growth
via Estrogen Receptors, Food and
Chemical Toxicology 59 (September 2013):
129-36. Abstract: Glyphosate is an active
ingredient of the most widely used herbicide and it
is believed to be less toxic than other pesticides.
However, several recent studies showed its potential
adverse health effects to humans as it may be an
endocrine disruptor. This study focuses on the
effects of pure glyphosate on estrogen receptors
(ERs) mediated transcriptional activity and their
expressions. Glyphosate exerted proliferative
effects only in human hormone-dependent breast
cancer, T47D cells, but not in hormone-independent
breast cancer, MDA-MB231 cells, at 10⁻¹² to 10⁻⁶M in
estrogen withdrawal condition. The proliferative
concentrations of glyphosate that induced the
activation of estrogen response element (ERE)
transcription activity were 5-13 fold of control in
T47D-KBluc cells and this activation was inhibited
by an estrogen antagonist, ICI 182780, indicating
that the estrogenic activity of glyphosate was
mediated via ERs. Furthermore, glyphosate also
altered both ERα and β expression. These results
indicated that low and environmentally relevant
concentrations of glyphosate possessed estrogenic
activity. Glyphosate-based herbicides are widely
used for soybean cultivation, and our results also
found that there was an additive estrogenic effect
between glyphosate and genistein, a phytoestrogen in
soybeans. However, these additive effects of
glyphosate contamination in soybeans need further
animal study. 33. Hong, C.-C.;
Tang, B.-K.; Hammond, G.L.; Tritchler, D.; Yaffe,
M.; Boyd, N.F. Cytochrome P450 1A2 (CYP1A2)
activity and risk factors for breast cancer: A
cross-sectional study. Breast Cancer Res. 2004, 6,
R352-R365. Abstract:
In both
menopausal groups CYP1A2 activity was positively
related to smoking and levels of sex hormone binding
globulin. In premenopausal women, CYP1A2 activity
was also positively related to insulin levels,
caffeine intake, age, and plasma triglyceride
levels, and negatively related with total
cholesterol levels and body mass index. In
postmenopausal women CYP1A2 activity was positively
associated with insulin-like growth factor-1, and
negatively associated with plasma triglyceride,
high-density lipoprotein cholesterol, and age at
menarche.These results suggest that CYP1A2 activity
is correlated with hormones, blood lipids, and
lifestyle factors associated with breast cancer
risk, although some of the observed associations
were contrary to hypothesized directions and suggest
that increased CYP1A2 function may be associated
with increased risk for breast cancer. 34. Samsel
A,
Seneff S.Glyphosate,
pathways to modern diseases IV: Cancer and related.
Journal
of
Biological Physics and Chemistry 15(2015) 121159 Abstract: Glyphosate is the active
ingredient in the pervasive herbicide, Roundup, and
its usage, particularly in the United States, has
increased dramatically in the last two decades, in
step with the widespread adoption of Roundup-Ready
core crops. The World Health Organization recently
labeled glyphosate as probably carcinogenic. In
this paper, we review the research literature, with
the goal of evaluating the carcinogenic potential of
glyphosate. Glyphosate has alarge number of
tumorigenic effects on biological systems, including
direct damage to DNA insensitive cells, disruption
of glycine homeostasis, succinate dehydrogenase
inhibition, chelation of manganese, modification to
more carcinogenic molecules such as
N-nitrosoglyphosate and glyoxylate, disruption of
fructose metabolism, etc. Epidemiological evidence
supports strong temporal correlations between
glyphosate usage on crops and a multitude of cancers
that are reaching epidemic proportions, including
breast cancer, pancreatic cancer, kidney cancer,
thyroid cancer, liver cancer, bladder cancer and
myeloid leukaemia. Here, we support these
correlations through an examination of Monsantos
early studies on glyphosate, and explain how the
biological effects of glyphosate could induce each
of these cancers. We believe that the available
evidence warrants a reconsideration of the
risk/benefit trade-off with respect to glyphosate
usage to control weeds, and we advocate much
stricter regulation of glyphosate. Non-Hodgkins
Lymphoma
(NHL) 35. Eriksson, M., Hardell, L.,
Carlberg, M., Akerman, M.
2008. Pesticide exposure as risk factor for
non-Hodgkin lymphoma including histopathological
subgroup analysis Int J Cancer.
Oct 1 2008;123(7):
16571663. Abstract: We report a population based
case-control study of exposure to pesticides as risk
factor for non-Hodgkin lymphoma (NHL). Male and
female subjects aged 18-74 years living in Sweden
were included during December 1, 1999, to April 30,
2002. Controls were selected from the national
population registry. Exposure to different agents
was assessed by questionnaire. In total 910 (91 %)
cases and 1016 (92%) con 51. Regarding phenoxyacetic
acids highest risk was calculated for MCPA; OR 2.81,
95% CI 1.27-6.22, all these cases had a latency
period >10 years. Exposure to glyphosate gave OR
2.02, 95% CI 1.10-3.71 and with >10 years latency
period OR 2.26, 95% CI 1.16-4.40. Insecticides
overall gave OR 1.28, 95% CI 0.96-1.72 and
impregnating agents OR 1.57, 95% CI 1.07-2.30.
Results are also presented for different entities of
NHL. In conclusion our study confirmed an
association between exposure to phenoxyacetic acids
and NHL and the association with glyphosate was
considerably strengthened. Tetragenic
(Birth Defects) 36. Lajmanovich, Raafael C.,
Sandoval, M.T., Peltzer, Paola M.
,
Induction of Mortality and Malformation in
Scinaxnasicus Tadpoles Exposed to Glyphosate
Formulations. Bulletin of
Environmental Contamination Toxicology 70 no.3
(March 2003): 612-18. Abstract: Larval maldevelopment
(craniofacial and mouth deformities, eye
abnormalities and bent curved tails) occurred in all
tests and increased with time and GLY-F
concentration. ... Malformation were minimal at 3.07
mg/L exposed for one day, whereas greater that 90%
were malformed at a GLY-F level of 7.5 mg/L. The
current test confirmed the malformation effects of
GLY-F on tadpoles. 37. Paganelli,
Alejandra et al.,
Glyphosate-Based Herbicides Produce Teratogenic
Effects on Vertebrates by Impairing Retinoic Acid
Signaling, Chemical
Research in Toxicology 23, no. 10 (August
2010): 1586-95. Abstract: The broad spectrum herbicide
glyphosate is widely used in agriculture worldwide.
There has been ongoing controversy regarding the
possible adverse effects of glyphosate on the
environment and on human health. Reports of neural
defects and craniofacial malformations from regions
where glyphosate-based herbicides (GBH) are used led
us to undertake an embryological approach to explore
the effects of low doses of glyphosate in
development. Xenopuslaevis embryos were
incubated with 1/5000 dilutions of a commercial GBH.
The treated embryos were highly abnormal with marked
alterations in cephalic and neural crest development
and shortening of the anterior−posterior (A-P) axis.
Alterations on neural crest markers were later
correlated with deformities in the cranial
cartilages at tadpole stages. Embryos injected with
pure glyphosate showed very similar phenotypes.
Moreover, GBH produced similar effects in chicken
embryos, showing a gradual loss of rhombomere
domains, reduction of the optic vesicles, and
microcephaly. This suggests that glyphosate itself
was responsible for the phenotypes observed, rather
than a surfactant or other component of the
commercial formulation. A reporter gene assay
revealed that GBH treatment increased endogenous
retinoic acid (RA) activity in Xenopus
embryos and cotreatment with a RA antagonist rescued
the teratogenic effects of the GBH. Therefore, we
conclude that the phenotypes produced by GBH are
mainly a consequence of the increase of endogenous
retinoid activity. This is consistent with the
decrease of Sonic hedgehog (Shh) signaling from the
embryonic dorsal midline, with the inhibition of otx2
expression and with the disruption of cephalic
neural crest development. The direct effect of
glyphosate on early mechanisms of morphogenesis in
vertebrate embryos opens concerns about the clinical
findings from human offspring in populations exposed
to GBH in agricultural fields. 38. Marc,
Julie.;
Mulner-Lorillon, O.; Boulben, S.; Hureau, D.;
Durand, G.; Bell, R.
Pesticide roundup provokes cell division
dysfunction at the level of CDK1/cyclin B
activation. Chem. Res. Toxicol. 2002, 15,
326331. Abstract:
To assess
human health risk from environmental chemicals, we
have studied the effect on cell cycle regulation of
the widely used glyphosate-containing pesticide
Roundup. As a model system we have used sea urchin
embryonic first divisions following fertilization,
which are appropriate for the study of universal
cell cycle regulation without interference with
transcription. We show that 0.8% Roundup (containing
8 mM glyphosate) induces a delay in the kinetic of
the first cell cleavage of sea urchin embryos. The
delay is dependent on the concentration of Roundup.
The delay in the cell cycle could be induced using
increasing glyphosate concentrations (1-10 mM) in
the presence of a subthreshold concentration of
Roundup 0.2%, while glyphosate alone was
ineffective, thus indicating synergy between
glyphosate and Roundup formulation products. The
effect of Roundup was not lethal and involved a
delay in entry into M-phase of the cell cycle, as
judged cytologically. Since CDK1/cyclin B regulates
universally the M-phase of the cell cycle, we
analyzed CDK1/cyclin B activation during the first
division of early development. Roundup delayed the
activation of CDK1/cyclin B in vivo. Roundup
inhibited also the global protein synthetic rate
without preventing the accumulation of cyclin B. In
summary, Roundup affects cell cycle regulation by
delaying activation of the CDK1/cyclin B complex, by
synergic effect of glyphosate and formulation
products. Considering the universality among species
of the CDK1/cyclin B regulator, our results question
the safety of glyphosate and Roundup on human
health. 39. Marc,
Julie,Bell, R.; Morales, J.; Cormier, P.;
Mulner-Lorillon, O. Formulated
glyphosate activates the DNA-response checkpoint of
the cell cycle leading to the prevention of G2/M
transition. Toxicoogicall. Sciences. 2004, 82,
436442. Abstract: A glyphosate containing
pesticide impedes at 10 mM glyphosate the G2/M
transition as judged from analysis of the first cell
cycle of sea urchin development. We show that
formulated glyphosate prevented dephosphorylation of
Tyr 15 of the cell cycle regulator CDK1/cyclin B in
vivo, the end point target of the G2/M cell
cycle checkpoint. Formulated glyphosate had no
direct effect on the dual specific cdc25 phosphatase
activity responsible for Tyr 15 dephosphorylation.
At a concentration that efficiently impeded the cell
cycle, formulated glyphosate inhibited the synthesis
of DNA occurring in S phase of the cell cycle. The
extent of the inhibition of DNA synthesis by
formulated glyphosate was correlated with the effect
on the cell cycle. We conclude that formulated
glyphosate's effect on the cell cycle is exerted at
the level of the DNA-response checkpoint of S phase.
The resulting inhibition of CDK1/cyclin B Tyr 15
dephosphorylation leads to prevention of the G2/M
transition and cell cycle progression. 40. Antoniou, Michael et al., Teratogenic
Effects of Glyphosate-Based Herbicides: Divergence
of Regulatory Decisions from Scientific Evidence. Journal of
Environmental and Analytical Toxicology (2012):S4:006.
Abstract: The publication of a study
in 2010 showing that a glyphosate herbicide
formulation and glyphosate alone caused
malformations in the embryos of Xenopuslaevis and
chickens caused a scientific and political
controversy. Debate centered on the effects of the
production and consumption of genetically modified
Roundup Ready soy, which is engineered to tolerate
applications of glyphosate herbicide. This study,
along with others indicating teratogenic and
reproductive effects from glyphosate herbicide
exposure, was rebutted by the German Federal Office
for Consumer Protection and Food Safety, BVL, as
well as in industry-sponsored papers. These
rebuttals relied partly on unpublished
industry-sponsored studies commissioned for
regulatory purposes, which, it was claimed, showed
that glyphosate is not teratogenic or a reproductive
toxin. However, examination of the German
authorities draft assessment report (DAR) on the
industry studies, which underlies glyphosates EU
authorisation, revealed further evidence of
glyphosates teratogenicity. Nevertheless, the
German and EU authorities minimized these findings
in their assessment and set a potentially unsafe
acceptable daily intake (ADI) level for glyphosate.
This paper reviews the evidence on the
teratogenicity and reproductive toxicity of
glyphosate herbicides and concludes that a new and
transparent risk assessment needs to be conducted by
scientists who are independent of industry and of
the regulatory bodies that were involved in the
existing authorisation of glyphosate. 41. Arbuckle,
T.E.;
Lin, Z.; Mery, L.S.
An exploratory analysis of the effect of pesticide
exposure on the risk of spontaneous abortion in an
Ontario farm population. Environ. Health Persp.2001, 109,
851857. Abstract:The toxicity of pesticides
on human reproduction is largely
unknown--particularly how mixtures of pesticide
products might affect fetal toxicity. The Ontario
Farm Family Health Study collected data by
questionnaire on the identity and timing of
pesticide use on the farm, lifestyle factors, and a
complete reproductive history from the farm operator
and eligible couples living on the farm. A total of
2,110 women provided information on 3,936
pregnancies, including 395 spontaneous abortions. To
explore critical windows of exposure and target
sites for toxicity, we examined exposures separately
for preconception (3 months before and up to month
of conception) and post conception (first trimester)
windows and for early (< 12 weeks) and late
(12-19 weeks) spontaneous abortions. We observed
moderate increases in risk of early abortions for
preconception exposures to phenoxy acetic acid
herbicides [odds ratio (OR) = 1.5; 95% confidence
interval (CI), 1.1-2.1], triazines (OR = 1.4; 95%
CI, 1.0-2.0), and any herbicide (OR = 1.4; 95% CI,
1.1-1.9). For late abortions, preconception exposure
to glyphosate (OR = 1.7; 95% CI, 1.0-2.9),
thiocarbamates (OR = 1.8; 95% CI, 1.1-3.0), and the
miscellaneous class of pesticides (OR = 1.5; 95% CI,
1.0-2.4) was associated with elevated risks. Post
conception exposures were generally associated with
late spontaneous abortions. Older maternal age (>
34 years of age) was the strongest risk factor for
spontaneous abortions, and we observed several
interactions between pesticides in the older age
group using Classification and Regression Tree
analysis. This study shows that timing of exposure
and restricting analyses to more homogeneous
endpoints are important in characterizing the
reproductive toxicity of pesticides. 42. Rauh,
Virginia et al., Rain Anomalies in Children
Exposed Prenatally to a Common Organophosphate
Pesticide, Proceedings
of the National Academy of Sciences of the United
State of America 109, no. 20
(May 2012). Abstract:
Prenatal
exposure to chlorpyrifos (CPF), an organophosphate
insecticide, is associated with neurobehavioral
deficits in humans and animal models. We
investigated associations between CPF exposure and
brain morphology using magnetic resonance imaging in
40 children, 5.911.2 y, selected from a
nonclinical, representative community-based cohort.
Twenty high-exposure children (upper tertile of CPF
concentrations in umbilical cord blood) were
compared with 20 low-exposure children on cortical
surface features; all participants had minimal
prenatal exposure to environmental tobacco smoke and
polycyclic aromatic hydrocarbons. High CPF exposure
was associated with enlargement of superior
temporal, posterior middle temporal, and inferior
postcentralgyri bilaterally, and enlarged superior
frontal gyrus, gyrus rectus, cuneus, and precuneus
along the mesial wall of the right hemisphere. Group
differences were derived from exposure effects on
underlying white matter. A significant exposure × IQ
interaction was derived from CPF disruption of
normal IQ associations with surface measures in
low-exposure children. In preliminary analyses,
high-exposure children did not show expected sex
differences in the right inferior parietal lobule
and superior marginal gyrus, and displayed reversal
of sex differences in the right mesial superior
frontal gyrus, consistent with disruption by CPF of
normal behavioral sexual dimorphisms reported in
animal models. High-exposure children also showed
frontal and parietal cortical thinning, and an
inverse doseresponse relationship between CPF and
cortical thickness. This study reports significant
associations of prenatal exposure to a widely used
environmental neurotoxicant, at standard use levels,
with structural changes in the developing human
brain. 43. Benachour,
N., Sralini, G. E. 2009.
Glyphosate formulations induce apoptosis and
necrosis in human umbilical, embryonic, and
placental cells. Chem Res
Toxicol 22: 97105. Abstract: We have evaluated the
toxicity of four glyphosate (G)-based herbicides in
Roundup formulations, from 10(5) times dilutions, on
three different human cell types. This dilution
level is far below agricultural recommendations and
corresponds to low levels of residues in food or
feed. The formulations have been compared to G alone
and with its main metabolite AMPA or with one known
adjuvant of R formulations, POEA. HUVEC primary
neonate umbilical cord vein cells have been tested
with 293 embryonic kidney and JEG3 placental cell
lines. All R formulations cause total cell death
within 24 h, through an inhibition of the
mitochondrial succinate dehydrogenase activity, and
necrosis, by release of cytosolic adenylate kinase
measuring membrane damage. They also induce
apoptosis via activation of enzymatic caspases 3/7
activity. This is confirmed by characteristic DNA
fragmentation, nuclear shrinkage (pyknosis), and
nuclear fragmentation (karyorrhexis), which is
demonstrated by DAPI in apoptotic round cells. G
provokes only apoptosis, and HUVEC are 100 times
more sensitive overall at this level. The
deleterious effects are not proportional to G
concentrations but rather depend on the nature of
the adjuvants. AMPA and POEA separately and
synergistically damage cell membranes like R but at
different concentrations. Their mixtures are
generally even more harmful with G. In conclusion,
the R adjuvants like POEA change human cell
permeability and amplify toxicity induced already by
G, through apoptosis and necrosis. The real
threshold of G toxicity must take into account the
presence of adjuvants but also G metabolism and
time-amplified effects or bioaccumulation. This
should be discussed when analyzing the in vivo toxic
actions of R. This work clearly confirms that the
adjuvants in Roundup formulations are not inert.
Moreover, the proprietary mixtures available on the
market could cause cell damage and even death around
residual levels to be expected, especially in food
and feed derived from R formulation-treated crops. Chronic Kidney
Disease 44. Jayasumana,
Channa, Gunatilake, Sarath, and Senanyake,
Priyantha, Glyphosate, Hard Water and
Nephrotixic Metals: Are they the Culprits Behind the
Epidemic of Chronic Kidney Disease of Unknown
Etiology in Sri Lanka? International
Journal of Environmental Research and Public
Health 11, no. 2 (February 2014): 2125-47. Abstract: The current chronic kidney
disease epidemic, the major health issue in the rice
paddy farming areas in Sri Lanka has been the
subject of many scientific and political debates
over the last decade. Although there is no agreement
among scientists about the etiology of the disease,
a majority of them has concluded that this is a
toxic nephropathy. None of the hypotheses put
forward so far could explain coherently the totality
of clinical, biochemical, histopathological
findings, and the unique geographical distribution
of the disease and its appearance in the mid-1990s.
A strong association between the consumption of hard
water and the occurrence of this special kidney
disease has been observed, but the relationship has
not been explained consistently. Here, we have
hypothesized the association of using glyphosate,
the most widely used herbicide in the disease
endemic area and its unique metal chelating
properties. The possible role played by
glyphosate-metal complexes in this epidemic has not
been given any serious consideration by
investigators for the last two decades. Furthermore,
it may explain similar kidney disease epidemics
observed in Andra Pradesh (India) and Central
America. Although glyphosate alone does not cause an
epidemic of chronic kidney disease, it seems to have
acquired the ability to destroy the renal tissues of
thousands of farmers when it forms complexes with a
localized geo environmental factor (hardness) and
nephrotoxic metals. Skin
and Oral Effects 45. Mariager,
T.P.; Madsen, P.V.; Ebbehj, N.E.; Schmidt, B.;
Juhl, A. Severe adverse effects related to
dermal exposure to a glyphosate-surfactant
herbicide. Clin.Toxicol.(Phila.).2013, 51,
111113. Abstract:
This is a
case of severe chemical burns following prolonged
accidental exposure to a glyphosate-surfactant
herbicide. The patient developed local swelling,
bullae and exuding wounds. Neurological impairment
followed affecting finger flexion and sensation with
reduced nerve conduction. Imaging revealed oedema of
the soft tissue and juxta-articular osteopenia, and
a causal relationship to exposure is suggested. 46. Deo, S.P., Shetty, P., Accidental
Burns of Oral Mucosa by Herbicide, JNMA J.
Nepal Med. Assoc. 2012, 52, 40-42. Abstract: Glyphosate (GlySH) is a
broad spectrum, nonselective herbicide, widely used
in agriculture. This case report describes a
25-year-old man presenting with extensive chemical
burns and ulceration of the oral cavity as a result
of accidental exposure to GlySH. This paper aims to
illustrate the typical appearance of GlySH related
chemical mucosal burn and to demonstrate the
severity of the corrosive effect of GlySH which need
team approach to prevent unfavorable sequelae such
as microstomia. 47. Kruger, Monika, et al
2014, Detection of glyphosate residues in animals
and humans, Environmental
and Analytical Toxicology, 4(2). Abstract: In the
present study glyphosate residues were tested in
urine and different organs of dairy cows as well as
in urine of hares, rabbits and humans using ELISA
and Gas Chromatography-Mass Spectroscopy (GC-MS).
The correlation coefficients between ELISA and GC-MS
were 0.96, 0.87, 0.97and 0.96 for cattle, human, and
rabbit urine and organs, respectively. The recovery
rate of glyphosate in spiked meat using ELISA was
91%. Glyphosate excretion in German dairy cows was
significantly lower than Danish cows. Cows kept in
genetically modified free area had significantly
lower glyphosate concentrations in urine than
conventional husbandry cows. Also glyphosate was
detected in different organs of slaughtered cows as
intestine, liver, muscles, spleen and kidney.
Fattening rabbits showed significantly higher
glyphosate residues in urine than hares. Moreover,
glyphosate was significantly higher in urine of
humans with conventional feeding. Furthermore,
chronically ill humans showed significantly higher
glyphosate residues in urine than healthy
population. The presence of glyphosate residues in
both humans and animals could haul the entire
population towards numerous health hazards, studying
the impact of glyphosate residues on health is
warranted and the global regulations for the use of
glyphosate may have to be re-evaluated. 48. Defarge N, Takcs E, Lozano VL, Mesnage R, Spiroux
de Vendmois J,
Sralini
GE, Szkcs A., Herbicides Disrupt
Aromatase Activity in Human Cells below Toxic Level
Co-Formulants in Glyphosate-Based ls. Int J
Environ Res Public Health.
2016 Feb 26;13(3). Abstract: Pesticide formulations contain
declared active ingredients and co-formulants
presented as inert and confidential compounds. We
tested the endocrine disruption of co-formulants in
six glyphosate-based herbicides (GBH), the most used
pesticides worldwide. All co-formulants and
formulations were comparably cytotoxic well below
the agricultural dilution of 1% (18-2000 times for
co-formulants, 8-141 times for formulations), and
not the declared active ingredient glyphosate (G)
alone. The endocrine-disrupting effects of all these
compounds were measured on aromatase activity, a key
enzyme in the balance of sex hormones, below the
toxicity threshold. Aromatase activity was decreased
both by the co-formulants alone (polyethoxylated
tallow amine-POEA and alkyl polyglucoside-APG) and
by the formulations, from concentrations 800 times
lower than the agricultural dilutions; while G
exerted an effect only at 1/3 of the agricultural
dilution. It was demonstrated for the first time
that endocrine disruption by GBH could not only be
due to the declared active ingredient but also to
co-formulants. These results could explain numerous
in vivo results with GBHs not seen with G alone;
moreover, they challenge the relevance of the
acceptable daily intake (ADI) value for GBHs
exposures, currently calculated from toxicity tests
of the declared active ingredient alone. 3. Impact
on the Environment Soil 49. Nicolas, V., N.
Oestreicher, and C. Vlot(2016). Multiple effects
of a commercial Roundup formulation on the soil
filamentous fungus Aspergillusnidulansat low
doses: evidence of an unexpected impact on
energetic metabolism.
Abstract:
Soil microorganisms are
highly exposed to glyphosate-based herbicides (GBH),
especially to Roundup which is widely used
worldwide. However, studies on the effects of GBH
formulations on specific non-rhizosphere soil
microbial species are scarce. We evaluated the
toxicity of a commercial formulation of Roundup
(R450), containing 450 g/L of glyphosate (GLY),
on the soil filamentous fungus Aspergillus
nidulans, an experimental model
microorganism. The median lethal dose (LD50)
on solid media was between 90 and 112 mg/L GLY
(among adjuvants, which are also included in the
Roundup formulation), which corresponds to a
dilution percentage about 100 times lower than that
used in agriculture. The LOAEL and NOAEL (lowest-
and no-observed-adverse-effect levels) associated to
morphology and growth were 33.75 and 31.5 mg/L
GLY among adjuvants, respectively. The formulation
R450 proved to be much more active than technical
GLY. At the LD50 and lower
concentrations, R450 impaired growth, cellular
polarity, endocytosis, and mitochondria (average
number, total volume and metabolism). In contrast
with the depletion of mitochondrial activities
reported in animal studies, R450 caused a
stimulation of mitochondrial enzyme activities, thus
revealing a different mode of action of Roundup on
energetic metabolism. These mitochondrial
disruptions were also evident at a low dose
corresponding to the NOAEL for macroscopic
parameters, indicating that these mitochondrial
biomarkers are more sensitive than those for growth
and morphological ones. Altogether, our data
indicate that GBH toxic effects on soil filamentous
fungi, and thus potential impairment of soil
ecosystems, may occur at doses far below recommended
agricultural application rate. Environmental Science
and Pollution Research, pp.1-12 DOI
10.1007/s11356-016-6596-2. 50. Bergstrm
L, Brjesson E &StenstrmJ (2011)
Laboratory and Lysimeter,Studies of Glyphosate and
Aminomethylphosphonic Acid in a Sand and a Clay
SoilJournal
of Environmental QualityVol 40 pp 98 108. Abstract: Due to the increasing
concern about the appearance of glyphosate
[N-(phosphonomethyl)glycine] and its major
metabolite aminomethylphosphonic acid (AMPA) in
natural waters, batch laboratory and lysimeter
transport studies were performed to assess the
potential for leaching of the compounds in two
agricultural soils. Unlabeled and 14C-labeled
glyphosate were added at a rate corresponding to
1.54 kg a.i. ha(-1) on undisturbed sand and clay
columns. Leachate was sampled weekly during a period
of 748 d for analyses of glyphosate, AMPA, total
14C, and particle-bound residues. Topsoil and
subsoil samples were used for determination of
glyphosate adsorption, glyphosate degradation, and
formation of AMPA and its degradation. The influence
of adsorption on glyphosate degradation was
confirmed, giving very slow degradation rate in the
clay soil (half-life 110-151 d). The kinetics of
AMPA residues suggest that although AMPA is always
more persistent than glyphosate when formed from
glyphosate, its degradation rate can be faster than
that of glyphosate. The kinetics also suggest that
apart from glyphosate being transformed to AMPA, the
sarcosine pathway can be just as significant. The
long persistence of glyphosate was also confirmed in
the lysimeter study, where glyphosate+AMPA residues
constituted 59% of the initial amount of glyphosate
added to the clay soil 748 d after application.
Despite large amounts of precipitation in the autumn
and winter after application, however, these
residues were mainly located in the topsoil, and
only 0.009 and 0.019% of the initial amount of
glyphosate added leached during the whole study
period in the sand and clay, respectively. No
leaching ofAMPA occurred in the sand, whereas 0.03 g
ha(-1) leached in the clay soil. 51. Simonsen
L, Fomsgard IS, Svensmark B &SplidNH. 2008.
Fate and availability of glyphosate and AMPA in
agricultural soil. Journal of
Environmental Science and Health Part B43:
365-375. Abstract: The fate of glyphosate and
its degradation product aminomethylphosphonic acid
(AMPA) was studied in soil. Labeled glyphosate was
used to be able to distinguish the measured
quantities of glyphosate and AMPA from the
background values since the soil was sampled in a
field where glyphosate had been used formerly. After
addition of labeled glyphosate, the disappearance of
glyphosate and the formation and disappearance of
AMPA were monitored. The resulting curves were
fitted according to a new EU guideline. The best fit
of the glyphosate degradation data was obtained
using a first-order multi compartment (FOMC) model.
DT(50) values of 9 days (glyphosate) and 32 days
(AMPA) indicated relatively rapid degradation. After
an aging period of 6 months, the leaching risk of
each residue was determined by treating the soil
with pure water or a phosphate solution (pH 6), to
simulate rain over a non-fertilized or fertilized
field, respectively. Significantly larger (p <
0.05) amounts of aged glyphosate and AMPA were
extracted from the soil when phosphate solution was
used as an extraction agent, compared with pure
water. This indicates that the risk of leaching of
aged glyphosate and AMPA residues from soil is
greater in fertilized soil. The blank soil, to which
252 g glyphosate/ha was applied 21 months before
this study, contained 0.81 ng glyphosate/g dry soil
and 10.46 ng AMPA/g dry soil at the start of the
study. Blank soil samples were used as controls
without glyphosate addition. After incubation of the
blank soil samples for 6 months, a significantly
larger amount of AMPA was extracted from the soil
treated with phosphate solution than from that
treated with pure water. To determine the degree of
uptake of aged glyphosate residues by crops growing
in the soil, (14)C-labeled glyphosate was applied to
soil 6.5 months prior to sowing rape and barley
seeds. After 41 days, 0.006 +/- 0.002% and 0.005 +/-
0.001% of the applied radioactivity was measured in
rape and barley, respectively. 52. Eker,
S., Ozturk, L., Yazici, A., Erenoglu, B., Rmheld,
V., Cakmak, I.,
2006. Foliarapplied glyphosate substantially
reduced uptake and transport of iron and manganese
in sunflower (Helianthus annuus L.)J. Agric. Food Chem., 2006, 54 (26), pp
1001910025. Abstract: Evidence clearly shows that
cationic micronutrients in spray solutions reduce
the herbicidal effectiveness of glyphosate for weed
control due to the formation of metal−glyphosate
complexes. The formation of these glyphosate−metal
complexes in plant tissue may also impair
micronutrient nutrition of nontarget plants when
exposed to glyphosate drift or glyphosate residues
in soil. In the present study, the effects of
simulated glyphosate drift on plant growth and
uptake, translocation, and accumulation (tissue
concentration) of iron (Fe), manganese (Mn), zinc
(Zn), and copper (Cu) were investigated in sunflower
(Helianthus annuus L.) plants grown in
nutrient solution under controlled environmental
conditions. Glyphosate was sprayed on plant shoots
at different rates between 1.25 and 6.0% of the
recommended dosage (i.e., 0.39 and 1.89 mM
glyphosate isopropylamine salt). Glyphosate
applications significantly decreased root and shoot
dry matter production and chlorophyll concentrations
of young leaves and shoot tips. The basal parts of
the youngest leaves and shoot tips were severely
chlorotic. These effects became apparent within 48 h
after the glyphosate spray. Glyphosate also caused
substantial decreases in leaf concentration of Fe
and Mn while the concentration of Zn and Cu was less
affected. In short-term uptake experiments with
radiolabeled Fe (59Fe), Mn (54Mn),
and Zn (65Zn), root uptake of 59Fe
and 54Mn was significantly reduced in 12
and 24 h after application of 6% of the recommended
dosage of glyphosate, respectively. Glyphosate
resulted in almost complete inhibition of
root-to-shoot translocation of 59Fe
within 12 h and 54Mn within 24 h after
application. These results suggest that glyphosate
residues or drift may result in severe impairments
in Fe and Mn nutrition of nontarget plants, possibly
due to the formation of poorly soluble
glyphosate−metal complexes in plant tissues and/or
rhizosphere interactions. 53. Springett,.AJ.&
Gray, R.A.J. 1992.
Effect of repeated low doses of biocides on the
earthworm Aporrecto deacaliginosa in laboratory
culture. Soil
Biology and Biochemistry24: 1739-1744. Abstract: Herbicides containing
glyphosate are widely used in agriculture and
private gardens, however, surprisingly little is
known on potential side effects on non-target soil
organisms. In a greenhouse experiment with white
clover we investigated, to what extent a
globally-used glyphosate herbicide affects
interactions between essential soil organisms such
as earthworms and arbuscularmycorrhizal fungi (AMF).
We found that herbicides significantly decreased
root mycorrhization, soil AMF spore biomass,
vesicles and propagules. Herbicide application and
earthworms increased soil hyphal biomass and tended
to reduce soil water infiltration after a simulated
heavy rainfall. Herbicide application in interaction
with AMF led to slightly heavier but less active
earthworms. Leaching of glyphosate after a simulated
rainfall was substantial and altered by earthworms
and AMF. These sizeable changes provide impetus for
more general attention to side-effects of
glyphosate-based herbicides on key soil organisms
and their associated ecosystem services. 54. Kremer RJ
& Means NE. 2009.
Glyphosate and glyphosate -resistant crop
interactions with rhizosphere microorganisms. European
Journal of Agronomy 31: 153-161, Abstract: Current crop production
relies heavily on transgenic, glyphosate-resistant
(GR) cultivars. Widespread cultivation of transgenic
crops has received considerable attention. Impacts
of glyphosate on rhizosphere microorganisms and
activities are reviewed based on published and new
data from long-term field projects documenting
effects of glyphosate applied to GR soybean and
maize. Field studies conducted in Missouri, U.S.A.
during 19972007 assessed effects of glyphosate
applied to GR soybean and maize on root colonization
and soil populations of Fusarium and
selected rhizosphere bacteria. Frequency of
root-colonizing Fusarium increased
significantly after glyphosate application during
growing seasons in each year at all sites. Roots of
GR soybean and maize treated with glyphosate were
heavily colonized by Fusarium compared to
non-GR or GR cultivars not treated with glyphosate.
Microbial groups and functions affected by
glyphosate included Mn transformation and plant
availability; phytopathogenantagonistic bacterial
interactions; and reduction in nodulation.
Root-exuded glyphosate may serve as a nutrient
source for fungi and stimulate propagule
germination. The specific microbial indicator groups
and processes were sensitive to impacts of GR crops
and are part of an evolving framework in developing
polyphasic microbial analyses for complete
assessment of GR technology that is more reliable
than single techniques or general microbial assays. 55. Kanissery, R.G., A.
Welsh, and G.K. Sims (2015). Effect of Soil
Aeration and Phosphate Addition on the Microbial
Bioavailability of Carbon-14-Glyphosate Abstract: The adsorption, desorption,
degradation, and mineralization of C-glyphosate
[-(phosphonomethyl)glycine] were examined in Catlin
(a fine-silty, mixed, superactive, mesic Oxyaquic
Argiudoll), Flanagan (a fine, smectitic, mesic Aquic
Argiudoll), and Drummer (a fine-silty, mixed,
superactive, mesic Typic Endoaquoll) soils under
oxic and anoxic soil conditions. With the exception
of the Drummer soil, soil aeration did not
significantly alter the adsorption pattern of
C-glyphosate to soils. Herbicide desorption was
generally enhanced with anaerobiosis in all the soil
types. Anoxic soils demonstrated slower microbial
degradation and mineralization kinetics of
C-glyphosate than oxic soils in all the soil types
studied. Phosphate additions significantly reduced
the adsorption of C-glyphosate to soils irrespective
of soil aeration and confirmed the well-established
competitive adsorption theory. The addition of soil
phosphate stimulated degradation only in anoxic
soils. The results from this research highlight the
importance of soil redox conditions as an important
factor affecting the bioavailability and mobility of
glyphosate in soils. Journal of
Environmental Quality, January 8, 2015,
Technical Reports, Biomediation and Biodegradation. 56. Newman, M.M., N. Hoilett,
N. Lorenz, R.P. Dick, M.R. Liles, C. Ramsier, and
J.W. Kloepper(2016).
Glyphosate effects on soil rhizosphere-associated
bacterial communities. Abstract:
Glyphosate
is one of the most widely used herbicides in
agriculture with predictions that
1.35 million metric tons will be used
annually by 2017. With the advent of glyphosate
tolerant (GT) cropping more than 10 years ago,
there is now concern for non-target effects on soil
microbial communities that has potential to
negatively affect soil functions, plant health, and
crop productivity. Although extensive research has
been done on short-term response to glyphosate,
relatively little information is available on
long-term effects. Therefore, the overall objective
was to investigate shifts in the rhizosphere
bacterial community following long-term glyphosate
application on GT corn and soybean in the
greenhouse. In this study, rhizosphere soil was
sampled from rhizoboxes following 4 growth periods,
and bacterial community composition was compared
between glyphosate treated and untreated
rhizospheres using next-generation barcoded
sequencing. In the presence or absence of
glyphosate, corn and soybean rhizospheres were
dominated by members of the phyla Proteobacteria,
Acidobacteria, and Actinobacteria.
Proteobacteria (particularly gammaproteobacteria)
increased in relative abundance for both crops
following glyphosate exposure, and the relative
abundance of Acidobacteria decreased in
response to glyphosate exposure. Given that some
members of the Acidobacteria are involved
in biogeochemical processes, a decrease in their
abundance could lead to significant changes in
nutrient status of the rhizosphere. Our results also
highlight the need for applying culture-independent
approaches in studying the effects of pesticides on
the soil and rhizosphere microbial community. Science
of
the Total Environment,
543:155160. 57. Casabe, N.,
L. Piola, J. Fuchs, M.L. Oneto, L. Pamparato, S.
Basack, R. Gimenez, R. Massaro, J.C. Papa, and E.
Kesten(2007). Ecotoxicological assessment
of the effects of glyphosate and chlorpyrifos in an
Argentine soya field. Abstract: The objective of this work
was to evaluate the effects of chlorpyrifos on
earthworms and on soil functional parameters. An
integrated laboratory-field study was performed in a
wheat field in Argentina, sprayed with chlorpyrifos
at two recommended application rates (240 or 960 g
ha-1 a.i.). Laboratory tests included
neutral red retention time, comet assay (single cell
gel electrophoresis), and avoidance behavior, each
using the earthworm Eisenia andrei exposed
in soil collected 1 or 14 days after pesticide
application, and the bait-lamina test. Field tests
assessed organic matter breakdown using the
litterbag and bait-lamina assays. Earthworm
populations in the field were assessed using
formalin application and hand-sorting. The neutral
red retention time and comet assays were sensitive
biomarkers to the effects of chlorpyrifos on the
earthworm E. andrei; however, the
earthworm avoidance test was not sufficiently robust
to assess these effects. Feeding activity of soil
biota, assessed by the bait lamina test, was
significantly inhibited by chlorpyrifos after
97 days, but recovered by the 118th day
of the test. Litterbag test showed no significant
differences in comparison to controls. Earthworm
abundance in the field was too low to adequately
test the sensitivity of this assessment endpoint. Journal
of Soils and Sediment, 8, pp.18. 58. Contardo-Jara
V., E. Klingelmann, and C. Wiegand(2009).Bioaccumulation
of
glyphosate and its formulation Roundup ultra in Lumbriculus
variegatus and its effects on
biotransformation and antioxidant enzymes. Abstract: The bioaccumulation
potential of glyphosate and the formulation Roundup
Ultra, as well as possible effects on
biotransformation and antioxidant enzymes in
Lumbriculus variegatus were compared by four days
exposure to concentrations between 0.05 and 5 mg
L(-1) pure glyphosate and its formulation.
Bioaccumulation was determined using (14)C labeled
glyphosate. The bioaccumulation factor (BCF) varied
between 1.4 and 5.9 for the different
concentrations, and was higher than estimated from
logP(ow). Glyphosate and its surfactant POEA caused
elevation of biotransformation enzyme soluble
glutathione S-transferase at non-toxic
concentrations. Membrane bound glutathione
S-transferase activity was significantly elevated in
Roundup Ultra exposed worms, compared to treatment
with equal glyphosate concentrations, but did not
significantly differ from the control. Antioxidant
enzyme superoxide dismutase was significantly
increased by glyphosate but in particular by Roundup
Ultra exposure indicating oxidative stress. The
results show that the formulation Roundup Ultra is
of more ecotoxicological relevance than the
glyphosate itself. Environmental Pollution,
157(1):5763. 59. Correia, F.
V., and J.C. Moreira (2010).
Effects of glyphosate and 2,4-D on earthworms (Eiseniafoetida)
in laboratory tests. Abstract: Laboratory tests were
conducted to compare the effects of various
concentrations of glyphosate and 2,4-D on earthworms
(Eisenia foetida) cultured in Argissol
during 56 days of incubation. The effects on
earthworm growth, survival, and reproduction rates
were verified for different exposure times.
Earthworms kept in glyphosate-treated soil were
classified as alive in all evaluations, but showed
gradual and significant reduction in mean weight
(50%) at all test concentrations. For 2,4-D, 100%
mortality was observed in soil treated with 500 and
1,000 mg/kg. At 14 days, 30%40% mortality
levels were observed in all other concentrations. No
cocoons or juveniles were found in soil treated with
either herbicide. Glyphosate and 2,4-D demonstrated
severe effects on the development and reproduction
of Eisenia foetida in laboratory tests in
the range of test concentrations. Bulletin of
Environmental Contamination and Toxicology, 85,
pp.264268. 60. Druart,
C., M. Millet, R. Scheifler, O. Delhomme, and A.
de Vaufleury(2011).
Glyphosate
and glufosinate-based herbicides: Fate in soil,
transfer to, and effects on land snails. Abstract: The aim of this work was to
assess the transfer and effects of two widely used
herbicides on the land snail Helix aspersa
during long-term exposure under laboratory
conditions. Newly hatched snails were exposed for
168 days to soil and/or food contaminated with
a formulation of glyphosate (Bypass) or glufosinate
(Basta) at the recommended field doses and also at
10-fold this dose. Herbicide degradation patterns
showed that snails were mainly exposed during the
first 28 days. The DT50 of glyphosate and
glufosinate was established at 10.6 and
3.7 days, respectively. No significant effects
on survival and growth were determined. Concerning
genital tract maturation of the snails, exposure to
herbicides tended to decrease the development of the
albumen gland (inhibition of 43.5 32.8%). The presence of glyphosate
(6 mg kg−1 dry weight) was
demonstrated in snails exposed continuously to this
active ingredient at the highest concentration in
their food. These results showed a low effect
of herbicides at relevant concentrations in soil but
the detection of residues in tissues indicated a
potential risk of transfer to the food chain. This
chronic toxicity bioassay could complete the
available tests to assess toxicity of contaminants,
and more particularly pesticides, in soil. Journal
of Soils and Sediments, 11(8):13731384. 61. Garca-Prez, J.A., E.
Alarcn, Y. Hernndez, and C. Hernndez (2016). Impact of
litter contaminated with glyphosate-based herbicide
on the performance of Pontoscolexcorethrurus,
soil phosphatase activities and soil pH Abstract: The bioavailability of
glyphosate from plant residues may be high in the
soil matrix. In order to determine the impact of
litter contaminated with glyphosate (GLY) on the
growth and cocoon production of the earthworm
Pontoscolex corethrurus as well as on acid and basic
phosphatase activities and soil pH, a commercial
glyphosate-based herbicide was applied to three
types of litter mixed with soil. Earthworms from a
GLY-free coffee plantation were grown for 132 days
in microcosms in a two-factorial design. The first
factor was glyphosate (GLY; 21.6 g of glyphosate per
kg of litter, with two levels (−GLY, +GLY), and the
second factor was type of litter (Coffea arabica,
Musa cavendishii, Inga vera). All studied factors
(except days*litter*glyphosate interaction) had
significant effects on earthworm biomass (P <
0.05). Treatments with Coffea and Musa litter -GLY
had significantly higher biomass (P < 0.05),
whereas treatments with Inga litter -GLY and +GLY
had the lowest biomass. A decline in earthworm
biomass was detected in all treatments with
glyphosate (+GLY) after 72 days. No significant
effect on cocoon production was detected for the
main factors or their interaction. Litter type
showed a marginal effect (P = 0.06); the average (
SE) number of cocoons decreased from Musa (5.8
2.9) to Coffea (1.3 0.56) and Inga (0.17 0.17).
Soil pH significantly (P = 0.006) decreased at the
end of the experiment from 4.4 0.17 in -GLY to 3.9
0.06 in +GLY. Acid phosphatase activity increased
in treatments with Musa and Inga +GLY (P < 0.05),
while alkaline phosphatase activity in the same
substrates was higher in treatments with -GLY (P
< 0.05). We conclude that repeated application of
litter contaminated with glyphosate negatively
affects earthworm vitality and increases soil
acidity and acid phosphatase activity. Applied Soil
Ecology, available online 15 March
2016. 62. Gaupp-Berghausen, M., M.
Hofer, B. Rewald, and J.G. Zaller(2015). Glyphosate-based
herbicides reduce the activity and reproduction of
earthworms and lead to increased soil nutrient
concentrations., Abstract: Herbicide use is increasing
worldwide both in agriculture and private gardens.
However, our knowledge of potential side-effects on
non-target soil organisms, even on such eminent ones
as earthworms, is still very scarce. In a greenhouse
experiment, we assessed the impact of the most
widely used glyphosate-based herbicide Roundup on
two earthworm species with different feeding
strategies. We demonstrate, that the surface casting
activity of vertically burrowing earthworms (Lumbricus
terrestris) almost ceased three weeks after
herbicide application, while the activity of soil
dwelling earthworms (Aporrectodea caliginosa)
was not affected. Reproduction of the soil dwellers
was reduced by 56% within three months after
herbicide application. Herbicide application led to
increased soil concentrations of nitrate by 1592%
and phosphate by 127%, pointing to potential risks
for nutrient leaching into streams, lakes, or
groundwater aquifers. These sizeable
herbicide-induced impacts on agroecosystems are
particularly worrisome because these herbicides have
been globally used for decades.
Nature: Scientific
Reports, 5:12886,
DOI:10.1038/srep12886. 63. Gimsing,
A.L., Borggaard, O.K., Jacobsen, O.S., Aamand, J
and Sorensen (2004). Chemical
and microbiological soil characteristics controlling
glyphosate mineralization in Danish surface soils.
Abstract: The results showed that
glyphosate is initially adsorbed mostly in the upper
2 cm. It is than transported and adsorbed after few
days in deeper soil horizons with concomitant
increasing content of its metabolite
aminomethylphosphonic acid. Moreover, Fe-oxides seem
to be a key parameter for glyphosate and
aminomethylphosphonic adsorption in soils. This
study confirmed previous studies: the analysis
showed lower contents of dithionite-soluble and
Fe-oxides for the Chernozem, with consequently lower
adsorption of glyphosate and aminomethylphosphonic
as compared with the Cambisol and the Stagnosol. Applied
Soil Ecology, 2, pp. 233242.
DOI:10.1016/j.apsoil.2004.05.007 Aquatic Life
and Terrestrial Amphibians 64. Fabio Leonardo
Meza-Joya et al., Toxic,
cytotoxic, and genotoxic effects of a glyphosate
formulation (RoundupSLCosmoflux411F) in the
direct-developing frog Eleutherodactylusjohnstonei,Environmental and
Molecular Mutagenesis,Volume 54, Issue 5, pages 362373,June
2013. Abstract:The aerial spraying of
glyphosate formulations in Colombia to eradicate
illegal crops has generated great concern about its
possible impact on nontarget organisms, particularly
amphibians. This study evaluated the toxic,
cytotoxic, and genotoxic effects of a glyphosate
formulation (RoundupSLCosmoflux411F) in the
direct-developing frog Eleutherodactylusjohnstonei
by estimating the median lethal application rate (LC50),
median hemolytic application rate (HD50),
and extent of DNA damage using the in vitro and in
vivo Comet assays. Toxicity results indicated that
the application rate [37.4 g acid equivalent
(a.e.)/cm2] equivalent to that used in
aerial spraying (3.74 kg a.e./ha) is not lethal in
male and female adult frogs, whereas neonates are
highly sensitive. Glyphosate formulation at
application rates above 5.4 g a.e./cm2
(in vivo) and concentrations above 95 g a.e./mL (in
vitro) showed clear evidence of cytotoxicity. In
vivo and in vitro exposure of E. johnstonei
erythrocytes to the glyphosate formulation induced
DNA breaks in a dose-dependent manner with
statistically significant values (P < 0.05) at all doses tested.
DNA damage initially increased with the duration of
exposure and then decreased, suggesting that DNA
repair events were occurring during in vivo and in
vitro exposures. These results are discussed from
the perspective of possible ecotoxicological risks
to anuran species from exposure to glyphosate
formulation. 65. Relyea,
R.A. 2005c.
The lethal impact of roundup on aquatic and
terrestrial amphibians. Ecological
Applications15: 11181124. Abstract: The global decline in amphibian
diversity has become an international environmental
problem with a multitude of possible causes. There
is evidence that pesticides may play a role, yet few
pesticides have been tested on amphibians. For
example, Roundup is a globally common herbicide that
is conventionally thought to be nonlethal to
amphibians. However, Roundup has been tested on few
amphibian species, with existing tests conducted
mostly under laboratory conditions and on larval
amphibians. Recent laboratory studies have indicated
that Roundup may be highly lethal to North American
tadpoles, but we need to determine whether this
effect occurs under more natural conditions and in
post-meta-morphic amphibians. I assembled
communities of three species of North American
tadpoles in outdoor pond mesocosms that contained
different types of soil (which can absorb the
pesticide) and applied Roundup as a direct
overspray. After three weeks, Roundup killed 96100%
of larval amphibians (regardless of soil presence).
I then exposed three species of juvenile
(post-metamorphic) anurans to a direct overspray of
Roundup in laboratory containers. After one day,
Roundup killed 6886% of juvenile amphibians. These
results suggest that Roundup, a compound designed to
kill plants, can cause extremely high rates of
mortality to amphibians that could lead to
population declines. 66. Relyea, RA. 2005b. The impact of insecticides and herbicides on the biodiversity and productivity of aquatic communities. Ecological Applications, 15: 618. Abstract: Pesticides constitute a major anthropogenic addition to natural communities. In aquatic communities, a great majority of pesticide impacts are determined from single-species experiments conducted under laboratory conditions. Although this is an essential protocol to rapidly identify the direct impacts of pesticides on organisms, it prevents an assessment of direct and indirect pesticide effects on organisms embedded in their natural ecological contexts. In this study, I examined the impact of four globally common pesticides (two insecticides, carbaryl [Sevin] and malathion; two herbicides, glyphosate [Roundup] and 2,4-D) on the biodiversity of aquatic communities containing algae and 25 species of animals.Species richness was reduced by 15% with Sevin, 30% with malathion, and 22% with Roundup, whereas 2,4-D had no effect. Both insecticides reduced zooplankton diversity by eliminating cladocerans but not copepods (the latter increased in abundance). The insecticides also reduced the diversity and biomass of predatory insects and had an apparent indirect positive effect on several species of tadpoles, but had no effect on snails. The two herbicides had no effects on zooplankton, insect predators, or snails. Moreover, the herbicide 2,4-D had no effect on tadpoles. However, Roundup completely eliminated two species of tadpoles and nearly exterminated a third species, resulting in a 70% decline in the species richness of tadpoles. This study represents one of the most extensive experimental investigations of pesticide effects on aquatic communities and offers a comprehensive perspective on the impacts of pesticides when nontarget organisms are examined under ecologically relevant conditions. 67. Kelly,
D.W., Poulin, R., Tompkins, D.M.& Townsend,
C.R. (2010).
Synergistic effects of glyphosate formulation and
parasite infection on fish malformations and
survival. Journal of Applied Ecology47: 498504. Abstract: This is the first study to
show that parasites and glyphosate can act
synergistically on aquatic vertebrates at
environmentally relevant concentrations, and that
glyphosate might increase the risk of disease in
fish. Our results have important implications when
identifying risks to aquatic communities and suggest
that threshold levels of glyphosate currently set by
regulatory authorities do not adequately protect
freshwater systems.
Anthropogenic stressors such as pollutants
can modulate levels of parasitic infections in
aquatic animals by suppressing host immunity or
through some other mechanisms. One such mechanism
could involve increases in either the quantity or
quality of infective stages produced by parasites.
We investigated the effect of exposure of infected
snails, Potamopyrgusantipodarum, to
different concentrations of the widely-used
herbicide glyphosate, on (i) the production of
infective cercariae by three trematode species, Coitocaecumparvum,
Apatemon sp. and an undescribed renicolid,
and (ii) the survival of cercariae of the latter
species. For all three trematode species, infected
snails exposed over a month to low
(0.36 mg a.i. L−1) or
medium (3.6 mg a.i. L−1)
formulated glyphosate concentrations released
between 1.5 and 3 times more cercariae per day than
snails under control conditions. The similar pattern
seen in all trematodes suggests a general weakening
of the host benefiting any of its parasites rather
than some parasite species-specific mechanism. In
addition, the survival of renicolidcercariae
improved with increasing glyphosate concentrations,
with cercariae living about 50% longer in the medium
concentration (3.6 mg a.i. L−1)
than in control conditions. Our results demonstrate
a clear interaction between glyphosate pollution and
parasitism by trematodes in freshwater systems,
occurring at glyphosate concentrations recorded in
aquatic habitats, and within the environmental
exposure limit allowed in New Zealand freshwaters.
Future risk assessments and toxicity tests need to
consider indirect impacts resulting from infections
to invertebrate and vertebrate species penetrated by
cercariae and serving as second intermediate hosts
of trematodes. 68. Mineau,
Pierre,
Direct Losses of Birds to Pesticides Beginnings
of a Quantification, USDA Forest Service Gen.
Tech. Rep. PSW-GTR-191. 2005 Abstract:
Recent
analyses and modeling of avian pesticide field
studies have led to the conclusion that bird kills
are regular and frequent in insecticide-treated
fields. Unfortunately, data are seldom adequate to
quantify this mortality. Also, mortality is expected
to be highly variable in response to varying bird
presence in and around treated fields. Studies
reporting kills of birds in cornfields treated with
granular formulations of carbofuran provide a good
example of the types of calculations that are needed
to estimate direct bird losses in farm fields.
Several studies provide the means to correct carcass
counts for search efficiency and scavenging. Based
on typical Midwest cornfields, use of granular
carbofuran resulted in an estimated annual mortality
rate of 3.0 to 16 songbirds per ha of treated field,
the higher number corresponding to better field edge
habitat. Much larger kills also occurred where
fields bordered non-crop habitat more suitable for
birds. At the peak of its popularity in the United
States, this single product was conservatively
giving rise to an estimated annual loss of 17-91
million birds in cornfields alone. Granular
carbofuran formulations continue to be sold and used
in most Latin American countries on a wide variety
of crops. 69. Glusczak,
L, Dos Santos,Miron D, Moraes, B.S., Simes, R.R.,
Schetinger, M.R.C., Morsch, V.M. &Loro, V.L., 2007.
Acute effects of glyphosate herbicide on metabolic
and enzymatic parameters of silver catfish
(Rhamdiaquelen)Comparative
Biochemistry and Physiology Part C 146: 519-524. Abstract: Silver catfish
(Rhamdiaquelen; Teleostei) were exposed to
commercial formulation Roundup, a glyphosate
herbicide: 0 (control), 0.2 or 0.4 mg/L for 96 h.
Fish exposed to glyphosate showed an increase in
hepatic glycogen, but a reduction in muscle glycogen
at both concentrations tested. Glucose decreased in
liver and increased in muscle of fish at both
herbicide concentrations. Glyphosate exposure
increased lactate levels in liver and white muscle
at both concentrations. Protein levels increased in
liver and decreased in white muscle while levels of
ammonia in both tissues increased in fish at both
glyphosate concentrations. Specific AChE activity
was reduced in brain after treatments, no changes
were observed in muscle tissue. Catalase activity in
liver did not change during of exposure. Fish
exposed to glyphosate demonstrated increased TBARS
production in muscle tissue at both concentrations
tested. For both glyphosate concentrations tested
brain showed a reduction of TBARS after 96 h of
exposure. The present results showed that in 96 h,
glyphosate changed AChE activity, metabolic
parameters and TBARS production. The parameters
measured can be used as herbicide toxicity
indicators considering environmentally relevant
concentration. 70. Moore, L.J., L. Fuentes,
J. H. Rodgers, Jr., W.W. Bowerman, G. K. Yarrow,
W.Y. Chao, and W.C. Bridges, Jr. (2012). Relative toxicity
of the components of the original formulation of
Roundup to five north american anurans. Abstract: The responses of five North
American frog species that were exposed in an
aqueous system to the original formulation of
Roundup were compared. Carefully designed and
un-confounded laboratory toxicity tests are crucial
for accurate assessment of potential risks from the
original formulation of Roundup to North American
amphibians in aquatic environments. The formulated
mixture of this herbicide as well as its components,
isopropylamine (IPA) salt of glyphosate and the
surfactant MON 0818 (containing polyethoxylated
tallowamine (POEA)) were separately tested in 96 h
acute toxicity tests with Gosner stage 25 larval
anurans. Rana pipiens, R. clamitans, R. catesbeiana,
Bufo fowleri, and Hyla chrysoscelis were reared from
egg masses and exposed to a series of 11
concentrations of the original formulation of
Roundup herbicide, nine concentrations of MON 0818
and three concentrations of IPA salt of glyphosate
in static (non-renewal) aqueous laboratory tests.
LC50 values are expressed as glyphosate acid
equivalents (ae) or as mg/L for MON 0818
concentrations for comparison between the
formulation and components. R. pipiens was the most
sensitive of five species with 96 h-LC50 values for
formulation tests, for the five species, ranging
from 1.80 to 4.22 mg ae/L, and MON 0818 exposures
with 96 h-LC50 values ranging from 0.68 to 1.32
mg/L. No significant mortality was observed during
exposures of 96 h for any of the five species
exposed to glyphosate IPA salt at concentrations up
to 100 times the predicted environmental
concentration (PEC). These results agree with
previous studies which have noted that the
surfactant MON 0818 containing POEA contributes the
majority of the toxicity to the herbicide
formulations for fish, aquatic invertebrates, and
amphibians. These study results suggest that anurans
are among the most sensitive species, and emphasize
the importance of testing the herbicide formulation
in addition to its separate components to accurately
characterize the toxicity and potential risk of the
formulation. Ecotoxicology and
Environmental Safety, 78:128133. 71. Salbego, J.,
A. Pretto, C.R. Gioda, C.C. de Menezes, R.
Lazzari, J.R. Neto, B. Baldisserotto, and V.L.
Loro(2010). Herbicide formulation with
glyphosate affects growth, acetylcholinesterase
activity, and metabolic and hematological parameters
in piava (Leporinus obtusidens). Abstract: The teleost fish Leporinus
obtusidens (piava) was exposed to different
concentrations of Roundup, a commercial herbicide
formulation containing glyphosate (0, 1, or 5 mg
L(-1)), for 90 days. Acetylcholinesterase (AChE)
activity was verified in brain and muscle. Hepatic
and muscular metabolic parameters as well as some
hematological parameters were determined. The
results showed that brain AChE activity was
significantly decreased in fish exposed to 5 mg
L(-1) Roundup, whereas muscular AChE activity was
not altered. Both Roundup concentrations
significantly decreased liver glycogen without
altering the muscle glycogen content. Hepatic
glucose levels were reduced only in fish exposed to
5 mg L(-1) Roundup. Lactate levels in the liver and
muscle significantly increased in fish exposed to
both Roundup concentrations. Hepatic protein content
remained constant at 1 mg L(-1) but increased at 5
mg L(-1) Roundup. In the muscle however, protein
content decreased with increasing exposure
concentration. The herbicide exposure produced a
decrease in hematological parameters at both
concentrations tested. The majority of observed
effects occur at environmental relevant
concentrations, and in summary, the results show
that Roundup affects brain AChE activity as well as
metabolic and hematologic parameters of piavas.
Thus, we can suggest that long-term exposure to
Roundup causes metabolic disruption in Leporinus
obtusidens. Archives of
Environmental Contamination and Toxicology 58(3):
740745. 72. Sandrini,
J.Z., R.C. Rola, F.M. Lopes, H.F. Buffon, M.M.
Freitas, C.M.G. Martins, and C.E. Rosa (2013).
Effects of glyphosate on cholinesterase activity of
the mussel Perna perna and the fish Danio
rerio and Jenynsia multidentata: In
vitro studies. Abstract: Although the herbicide
glyphosate [N-(phosphonomethyl)glycine] is not
classified as an acethylcholinesterase inhibitor,
some studies have reported reduction in the
acethylcolinesterase activity after in vivo exposure
to both its pure form and its commercial
formulations. Considering this controversy, the
objective of the present study was to investigate,
in vitro, the effects of glyphosate exposure on
cholinesterase activity of the brown mussel Perna
perna and of two fish species: zebrafish Danio rerio
and onesided livebearer Jenynsia multidentata. For
this purpose, samples of different tissues (brain
and muscle for fish; gills and muscle for mussel)
were homogenized and pre-incubated with different
glyphosate concentrations before cholinesterase
activity determination. Results demonstrated that
cholinesterase from different fractions of all
species tested was inhibited by glyphosate. The
concentrations of glyphosate that inhibits 50% of
cholinesterase activity (IC50) ranged from 0.62 mM
for P. perna muscle to 8.43 mM for J. multidentata
brain. According to this, cholinesterase from mussel
seems to be more sensitive to glyphosate exposure
than those from the fish D. rerio and J.
multidentata. Aquatic
Toxicology, 130-131:171173. 73. Cattaneo,
R., B. Clasen, V.L. Loro, C.C. de Menezes, A.
Pretto, B. Baldisserotto, A. Santi, and L.A. de
Avila (2011). Toxicological responses of Cyprinus
carpio exposed to a commercial formulation
containing glyphosate. Abstract: The effects of commercial
glyphosate herbicide formulation on the activity of
acetylcholinesterase (AChE) enzyme and oxidative
stress were studied in the fish Cyprinus carpio
exposed for 96 h to 0.0, 0.5, 2.5, 5.0 and
10.0 mg/L and then allowed to equal recovery
period in water without herbicide. The activity of
AChE was inhibited in the brain and in the muscle
after exposure. However, after recovery period brain
and muscle AChE activity increased. Brain
thiobarbituric acid reactive species (TBARS) were
measured as an indicator of oxidative stress.
Increased TBARS levels were observed with all
concentrations tested of the glyphosate formulation,
and remained increased after the recovery period.
The results recorded clearly indicate lipid
peroxidation and anti-AChE action induced by Roundup
exposure. Bulletin of Environmental Contamination
and Toxicology, 87(6): 597602. 74. Costa
L.D.F., K.C. Miranda, M.P. Severo, and L.A.
Sampaio(2008). Tolerance of juvenile Pompano
trachinotus marginatus
to acute ammonia and nitrite exposure at different
salinity levels. Abstract: The present study was
conducted to estimate the acute toxicity of
unionized ammonianitrogen (NH3N) and
nitritenitrogen (NO2N) to juvenile
pompano Trachinotus marginatus
(0.86 0.21 g) at different salinity
levels: 5, 10 (equivalent to its isosmotic point),
and 30. Fish were acclimated to the different
salinities for 10 days and fed ad libitum
daily. Groups of five fishes were exposed
to five concentrations of NH3N and NO2N
for 96 h plus control groups for each salinity,
where no toxicant was added. Test concentrations
ranged from 0.28 to 3.53 mg NH3N/L
and 24.8 to 191.1 mg NO2N/L with
three replicates per treatment. Tests were run using
a standard semi-static system with 100% daily
renewal of water and toxicants. The results were
based on mortality data registered in different
concentrations tested, using the software Trimmed
Spearman Karber method. The median lethal
concentrations (LC50) after 96 h of
exposure to NH3N were 0.66 (0.530.81),
1.87 (1.652.12) and 1.06 (0.941.20) mg NH3N/L
for 5, 10, and 30. The 96 h LC50 to
NO2N were 39.94 (36.3943.84), 116.68 (112.52121.00) and
37.55 (20.9167.44) mg NO2N/L for 5, 10,
and 30. Acute toxicity of NH3N and NO2N
to pompano was affected by salinity. Results of the
present study show that pompano reared at an
isosmotic environment are less sensitive to NH3N
and NO2N. Tolerance to NH3N
is compromised at reduced salinities, while toxicity
of NO2N is similar at 5 and 30. Aquaculture,
285(1-4): 270272. 75. Cuhra, M.,
T. Traavik, and T. Bohn (2013).
Clone- and age-dependent toxicity of a glyphosate
commercial formulation and its active ingredient in
Daphnia magna. Abstract: Low levels of glyphosate
based herbicide induced significant negative effects
on the aquatic invertebrate Daphnia magna.
Glyphosate herbicides such as brands of Roundup, are
known to be toxic to daphnids. However, published
findings on acute toxicity show significant
discrepancies and variation across several orders of
magnitude. To test the acute effects of both
glyphosate and a commercial formulation of Roundup
(hereafter Roundup), we conducted a series of
exposure experiments with different clones and
age-classes of D. magna. The results demonstrated
EC(50) (48) values in the low ppm-range for Roundup
as well as for the active ingredient (a.i.)
isopropylamine salt of glyphosate (glyphosate IPA)
alone. Roundup showed slightly lower acute toxicity
than glyphosate IPA alone, i.e. EC(50) values of
3.7-10.6 mg a.i./l, as compared to 1.4-7.2 mg a.i./l
for glyphosate IPA. However, in chronic toxicity
tests spanning the whole life-cycle, Roundup was
more toxic. D. magna was exposed to sublethal
nominal concentrations of 0.05, 0.15, 0.45, 1.35 and
4.05 mg a.i./l for 55 days. Significant reduction of
juvenile size was observed even in the lowest test
concentrations of 0.05 mg a.i./l, for both
glyphosate and Roundup. At 0.45 mg a.i./l, growth,
fecundity and abortion rate was affected, but only
in animals exposed to Roundup. At 1.35 and 4.05 mg
a.i./l of both glyphosate and Roundup, significant
negative effects were seen on most tested
parameters, including mortality. D. magna was
adversely affected by a near 100 % abortion rate of
eggs and embryonic stages at 1.35 mg a.i./l of
Roundup. The results indicate that aquatic
invertebrate ecology can be adversely affected by
relevant ambient concentrations of this major
herbicide. We conclude that glyphosate and Roundup
toxicity to aquatic invertebrates have been
underestimated and that current European Commission
and US EPA toxicity classification of these
chemicals need to be revised. Ecotoxicology,
22:251262, DOI 10.1007/s10646-012-1021-1. 76. Folmar, L.C., H.O.
Sanders, and A.M. Julin(1979). Toxicity of the
herbicide glyphosate and several of its formulations
to fish and aquatic invertebrates. Abstract: Studies were Initiated to determine the
acute toxicity of technical grade glyphosate
(MONC?573), the isopropylamine salt of glyphosate
(MONOI39), the formulated herbicide Roundup
(MON2139),and the Roundup surfactant (MON0818) to
four aquatic invertebrates and four fishes: daphnids
(Daphnia magna), scuds (G.aI1'l;TJ1arus
pseudolimnaeus) 1 midge larvae (Crlironomu.s
p,lumosus), mayfly nymphs (Ephemerella ~eri), rainbow trout (Salmo
gairdneri), fathead minnows (Pimephaes promelas),
channel catfish (Ictalurus punctatus), and bluegills
(Lepomis macrochirus). Acute toxicities for Roundup
ranged from 2.3 mg/l (96-h LC50, fathead minnow) to
43 mg/l (L.8-h EC50, mature scuds). Toxicities of
the surfactant were similar to those of the Roundup
formulation. Technical glyphosate was considerably
less toxic than Roundup or the surfactant; for midge
larvae the 48-h EC50 was 55 mg/l and for rainbow
trout the 96-h LC50 was 140 mg/l. Roundup was more
toxic to rainbow trout and bluegil1s at the higher
test temperatures, and at pH 7.5 than at pH 6.5.
Toxicity did not increase at pH 8.5 or 9.5. Eyed
eggs were the least sensitive life stage, but
toxicity increased markedly as the fish entered the
sac fry and early swim-up stages. No changes in
fecundity or gonadosomatic index were observed in
adult rainbow trout. Archives
of Environmental Contamination and Toxicology,
8(3):269278. 77. Frontera, J.L., I.
Vatnick, A. Chaulet, and E. M. Rodriguez (2011). Effects of
glyphosate and polyoxyethylenamine on growth and
energetic reserves in the freshwater crayfish Cheraxquadricarinatus
(Decapoda, Parastacidae). Abstract: Freshwater crayfish Cherax
quadricarinatus have a high commercial value
and are cultured in farms where they are potentially
exposed to pesticides. Therefore, we examined the
sublethal effects of a 50-day exposure to glyphosate
acid and polyoxyethylenamine (POEA), both alone and
in a 3:1 mixture, on the growth and energetic
reserves in muscle, hepatopancreas and hemolymph of
growing juvenile crayfish. Exposure to two different
glyphosate and POEA mixtures caused lower somatic
growth and decreased muscle protein levels. These
effects, caused by both compounds interacting in the
mixture, could also be synergistic because they were
expressed even at the lowest concentration. The
decrease in protein levels could be related to the
greater use of other energy reserves. This
hypothesis is supported by the decrease in muscle
glycogen stores due to glyphosate exposure and the
decrease in lipid reserves associated with exposure
to POEA.Archives
of
Environmental Contamination and Toxicology,
61(4):590598. 78. Fuentes,
L., L.J. Moore, J.H. Rodgers, W.W. Bowerman, G. K.
Yarrow, and W. Y. Chao (2011).
Comparative
toxicity of two glyphosate formulations (original
formulation of Roundup and Roundup Weathermax )
to six North American larval anurans. Abstract: The toxicity of two
glyphosate formulations (the original formulation of
Roundup and Roundup WeatherMAX) to six species of
North American larval anurans was evaluated by using
96-h static, nonrenewal aqueous exposures. The 96-h
median lethal concentration values (LC50) ranged
from 1.80 to 4.22 mg acid
equivalent (ae)/L and 1.96 to 3.26 mg ae/L for the original
formulation of Roundup and Roundup WeatherMAX,
respectively. Judged by LC50 values, four species
were more sensitive to Roundup WeatherMAX exposures,
and two species were more sensitive to the original
formulation. Two of six species, Bufo fowleri
(p < 0.05, F = 14.89, degrees of freedom [df] = 1) and Rana clamitans
(p < 0.05, F = 18.46, df = 1), had significantly
different responses to the two formulations tested.
Increased sensitivity to Roundup WeatherMAX likely
was due to differences in the surfactants or
relative amounts of the surfactants in the two
formulations. Potency slopes for exposures of the
original formulation ranged from 24.3 to 92.5%
mortality/mg ae/L. Thresholds ranged from 1.31 to
3.68 mg ae/L, showing an
approximately three times difference in the
initiation of response among species tested. For
exposures of Roundup WeatherMAX, slopes ranged from
49.3 to 84.2% mortality/mg ae/L. Thresholds ranged
from 0.83 to 2.68 mg ae/L.
Margins of safety derived from a simulated direct
overspray were above 1, except for one species in
exposures of Roundup WeatherMAX. Laboratory data
based on aqueous exposures are conservative because
of the lack of environmental ligands; however, these
tests provide information regarding the relative
toxicity between these two Roundup formulations. Environmental
Toxicology
and Chemistry, 30(12):27562761. 79. Glusczak,
L., V.L. Loro, A. Pretto, B.S. Moraes, A. Raabe,
M.F. Duarte, M.B. da Fonseca, C.C. de Menezes,
D.M.D. Valladao(2011). Acute exposure to
glyphosate herbicide affects oxidative parameters in
Piava (Leporinusobtusidens). Abstract: In recent years, commercial
glyphosate herbicide formulations have been widely
used in agriculture to control aquatic weeds. These
pesticides may result in disruption of ecological
balance, causing damage to nontarget organisms
including fish. Teleostean fish (Leporinus
obtusidens) were exposed to commercial
glyphosate herbicide formulation at 0 (control), 3,
6, 10 or 20 mg L−1 for
96 h. The effects of herbicide on plasmatic
metabolic parameters, thiobarbituric acid reactive
substances (TBARS), catalase activity, protein
carbonyl, and mucus layer parameters were studied.
Plasmatic glucose and lactate levels increased but
protein levels showed reduction after herbicide
exposure. TBARS levels in brain showed a reduction
at all tested concentrations. However, liver
demonstrated increased TBARS levels at all tested
concentrations, whereas in white muscle TBARS
production did not change after exposure to
herbicide. Fish exposed to all concentrations of
glyphosate showed increase in liver catalase
activity and protein carbonyl. Herbicide exposure
increased protein and carbohydrate levels of the
mucus layer at all tested concentrations. The
present results showed that, in 96 h,
glyphosate changed toxicological parameters analyzed
in piava. Parameters measured in this study may be
useful in environmental biomonitoring.Archives of
Environmental Contamination and Toxicology, 61: 624630. 80. Glusczak,
L., dos Santos, D. Miron, B.S. Moraes, R.R.
Simoes, M.R.C. Schetinger, V.M. Morsch, and V.L.
Loro(2007). Acute
effects of glyphosate herbicide on metabolic and
enzymatic parameters of silver catfish (Rhamdiaquelen).
Abstract: We investigated the effects
of four commercial formulations of herbicides
(glyphosate [GLY], metsulfuron-methyl [MET],
bispyribac-sodium [BIS], and picloram [PIC])
individually, and in three 50:50 mixtures (GLYMET,
GLYBIS, GLYPIC) on the common toad Rhinella
arenarum (Anura: Bufonidae) tadpoles.
Enzymatic parameters such as, glutathione S-transferase
(GST), butyrylcholinesterase (BChE) and
acetylcholinesterase (AChE) activities, as well as
erythrocyte nuclear abnormalities (ENA) were
studied. Interactions between herbicides in mixtures
were evaluated and classified as additive,
synergistic, or antagonistic. Toxicity results (48-h
LC50) showed that PIC was the most toxic
herbicide, followed by BIS, GLY, and MET, while
GLYPIC was the most toxic mixture, followed by
GLYBIS, and GLYMET. All commercial herbicide
formulations and their mixtures significantly
inhibited BChE activity in exposed tadpoles. The
AChE activity was also inhibited by all herbicides
and their mixtures, except by GLYBIS. The
inhibition of GST activity was only significant for
GLY, MET, PIC, and GLYMET. A significant increase
in the frequency of ENA was found for tadpoles
exposed either to commercial herbicide formulations
or to mixtures, except for GLY. All the mixtures
showed synergism for BChE activity while for AChE
only the GLYMET and GLYPIC mixtures acted
synergistically. GLYMET showed synergism for GST,
whereas for ENA, the mixture GLYBIS was
antagonistic. This study with R. arenarum
tadpoles demonstrates that the interactions between
three of the most intensively used herbicides in
soybean crops results in synergistic effects on
mortality and neurotoxicity and synergistic or
additive effects in genotoxicity. Comparative
Biochemistry and Physiology- Pharmacology,
Toxicology and Endocrinology, 146(4):519524. 81. Guilherme,
S., I. Gaivao, M.A. Santos, and M. Pacheco (2012). DNA
damage in fish (Anguilla anguilla) exposed to
a glyphosate-based herbicide -elucidation of
organ-specificity and the role of oxidative stress.
Mutation
Research, Abstract: Organophosphate herbicides
are among the most dangerous agrochemicals for the
aquatic environment. In this context, Roundup(), a
glyphosate-based herbicide, has been widely detected
in natural water bodies, representing a potential
threat to non-target organisms, namely fish. Thus,
the main goal of the present study was to evaluate
the genotoxic potential of Roundup() in the teleost
fish Anguilla anguilla, addressing the possible
causative involvement of oxidative stress. Fish were
exposed to environmentally realistic concentrations
of this herbicide (58 and 116 μgL(-1)) during one or
three days. The standard procedure of the comet
assay was applied to gill and liver cells in order
to determine organ-specific genetic damage. Since
liver is a central organ in xenobiotic metabolism,
nucleoids of hepatic cells were also incubated with
a lesion-specific repair enzyme (formamidopyrimidine
DNA glycosylase - FPG), in order to recognise
oxidised purines. Antioxidants were determined in
both organs as indicators of pro-oxidant state. In
general, both organs displayed an increase in DNA
damage for the two Roundup() concentrations and
exposure times, although liver showed to be less
susceptible to the lower concentration. The
enzyme-modified comet assay showed the occurrence of
FPG-sensitive sites in liver only after a 3-day
exposure to the higher Roundup() concentration. The
antioxidant defences were in general unresponsive,
despite a single increment of catalase activity in
gills (116 μgL(-1), 3-day) and a decrease of
superoxide dismutase activity in liver (58 μgL(-1),
3-day). Overall, the mechanisms involved in
Roundup()-induced DNA strand-breaks showed to be
similar in both organs. Nevertheless, it was
demonstrated that the type of DNA damage varies with
the concentration and exposure duration. Hence,
after 1-day exposure, an increase on pro-oxidant
state is not a necessary condition for the induction
of DNA-damaging effects of Roundup(). By increasing
the duration of exposure to three days,
ROS-dependent processes gained preponderance as a
mechanism of DNA-damage induction in the higher
concentration. Genetic Toxicology and Environmental
Mutagenesis, 743: 19. 82. Guilherme,
S., I. Gaivao, M.A. Santos, and M. Pacheco (2010).
European eel (Anguilla anguilla) genotoxic and
pro-oxidant responses following short-term exposure
to Roundup - a glyphosate-based herbicide. Abstract: The glyphosate-based
herbicide, Roundup, is among the most used
pesticides worldwide. Due to its extensive use, it
has been widely detected in aquatic ecosystems
representing a potential threat to non-target
organisms, including fish. Despite the negative
impact of this commercial formulation in fish, as
described in literature, the scarcity of studies
assessing its genotoxicity and underlying mechanisms
is evident. Therefore, as a novel approach, this
study evaluated the genotoxic potential of Roundup
to blood cells of the European eel (Anguilla
anguilla) following short-term (1 and 3 days)
exposure to environmentally realistic concentrations
(58 and 116 microg/l), addressing also the possible
association with oxidative stress. Thus, comet and
erythrocytic nuclear abnormalities (ENAs) assays
were adopted, as genotoxic end points, reflecting
different types of genetic damage. The pro-oxidant
state was assessed through enzymatic (catalase,
glutathione-S-transferase, glutathione peroxidase
and glutathione reductase) and non-enzymatic (total
glutathione content) antioxidants, as well as by
lipid peroxidation (LPO) measurements. The Roundup
potential to induce DNA strand breaks for both
concentrations was demonstrated by the comet assay.
The induction of chromosome breakage and/or
segregational abnormalities was also demonstrated
through the ENA assay, though only after 3-day
exposure to both tested concentrations. In addition,
the two genotoxic indicators were positively
correlated. Antioxidant defenses were unresponsive
to Roundup. LPO levels increased only for the high
concentration after the first day of exposure,
indicating that oxidative stress caused by this
agrochemical in blood was not severe. Overall
results suggested that both DNA damaging effects
induced by Roundup are not directly related with an
increased pro-oxidant state. Moreover, it was
demonstrated that environmentally relevant
concentrations of Roundup can pose a health risk for
fish populations. Mutagenesis, 25: 523530. 83. Hagner, M.,
S. Hallman, L. Jauhiainen, R. Kemppainen, S. Ram,
K. Tiikkala, and H. Setal(2015). Birch
(Betula spp.) wood biochar is a potential soil
amendment to reduce glyphosate leaching in
agricultural soils Abstract: Glyphosate
(N-(phosphonomethyl) glycine), a commonly used
herbicide in agriculture can leach to deeper soil
layers and settle in surface- and ground waters. To
mitigate the leaching of pesticides and nutrients,
biochar has been suggested as a potential soil
amendment due to its ability to sorb both organic
and inorganic substances. However, the efficiency of
biochar in retaining agro-chemicals in the soil is
likely to vary with feedstock material and pyrolysis
conditions. A greenhouse pot experiment, mimicking a
crop rotation cycle of three plant genera, was
established to study the effects of pyrolysis
temperature on the ability of birch (Betula
sp.) wood originated biochar to reduce the leaching
of (i) glyphosate, (ii) its primary degradation
product AMPA and (iii) phosphorus from the soil. The
biochar types used were produced at three different
temperatures: 300 C (BC300), 375 C
(BC375) and 475 C (BC475). Compared
to the control treatment without biochar, the
leaching of glyphosate was reduced by 81%, 74% and
58% in BC300, BC375 and BC475 treated soils,
respectively. The respective values for AMPA were
46%, 39% and 23%. Biochar had no significant effect
on the retention of water-soluble phosphorus in the
soil. Our results corroborate earlier findings on
pesticides, suggesting that biochar amendment to the
soil is a promising way to reduce also the leaching
of glyphosate. Importantly, the ability of biochar
to adsorb agro-chemicals depends on the temperature
at which feedstock is pyrolysed. Journal of
Environmental Management, 164:4652. Rain and
Atmosphere 84. Chang, Feng-chih, Simcik,
Matt F., Capel, Paul D., Occurrence and fate of
the herbicide glyphosate and its degradate
aminomethylphosphonic acid in the atmosphere. Environ Toxicol
Chem. 2011 Mar;30(3):548-55. Abstract: This is
the first report on the ambient levels of
glyphosate, the most widely used herbicide in the
United States, and its major degradation product,
aminomethylphosphonic acid (AMPA), in air and rain.
Concurrent, weekly integrated air particle and rain
samples were collected during two growing seasons in
agricultural areas in Mississippi and Iowa. Rain was
also collected in Indiana in a preliminary phase of
the study. The frequency of glyphosate detection
ranged from 60 to 100% in both air and rain. The
concentrations of glyphosate ranged from<0.01 to
9.1 ng/m(3) and from<0.1 to 2.5g/L in air and
rain samples, respectively. The frequency of
detection and median and maximum concentrations of
glyphosate in air were similar or greater to those
of the other high-use herbicides observed in the
Mississippi River basin, whereas its concentration
in rain was greater than the other herbicides. It is
not known what percentage of the applied glyphosate
is introduced into the air, but it was estimated
that up to 0.7% of application is removed from the
air in rainfall. Glyphosate is efficiently removed
from the air; it is estimated that an average of 97%
of the glyphosate in the air is removed by a weekly
rainfall 30 mm. 85. Chang FC,
Simcik MF and Capel P.,
2011. Occurrence and fate of the herbicide
glyphosate and its degradate Aminomethylphosphonic
acid in the atmosphere,Environmental
Toxicology and Chemistry30 : 548555 Abstract: This is the first report on
the ambient levels of glyphosate, the most widely
used herbicide in the United States, and its major
degradation product, aminomethylphosphonic acid
(AMPA), in air and rain. Concurrent, weekly
integrated air particle and rain samples were
collected during two growing seasons in agricultural
areas in Mississippi and Iowa. Rain was also
collected in Indiana in a preliminary phase of the
study. The frequency of glyphosate detection ranged
from 60 to 100% in both air and rain. The
concentrations of glyphosate ranged from <0.01 to
9.1 ng/m(3) and from <0.1 to 2.5 g/L in air and
rain samples, respectively. The frequency of
detection and median and maximum concentrations of
glyphosate in air were similar or greater to those
of the other high-use herbicides observed in the
Mississippi River basin, whereas its concentration
in rain was greater than the other herbicides. It is
not known what percentage of the applied glyphosate
is introduced into the air, but it was estimated
that up to 0.7% of application is removed from the
air in rainfall. Glyphosate is efficiently removed
from the air; it is estimated that an average of 97%
of the glyphosate in the air is removed by a weekly
rainfall 30 mm. Water and
Watersheds 86. Kaiser, Kristine,
Preliminary Study of Pesticide Drift into the Maya
Mountain Protected Areas of Belize Bull
Environ ContamToxicol. 2011 Jan; 86(1): 5659. Abstract: In
Belize, Central America, many farms surrounding the
Protected Areas of the Maya Mountains rely heavily
on the application of agrochemicals. The purpose of
this study was to test whether orographic drift of
glyphosate and organophosphates into the nearby Maya
Mountain Protected Areas occurred by collecting
phytotelmic water from seven sites over
3 years. Regardless of location within the Maya
Mountain Protected Areas, glyphosate was present;
organophosphates were more common at ridge sites.
Although glyphosate concentrations were low, due to
the number of threatened species and the human use
of stream water outside the Maya Mountain Protected
Areas, better understanding of these effects is
warranted.
87. Mercurio, Philip, Flores, Florita, Mueller, Jochen F., Carter, Steve, Negri, Andrew P.Glyphosate persistence in
seawater,Marine
Pollution Bulletin, Vol. 85, issue 2, 30 August
2014, Pages 385390. Abstract:
Glyphosate is one of the most widely applied
herbicides globally but its persistence in seawater
has not been reported. Here we quantify the
biodegradation of glyphosate using standard
simulation flask tests with native bacterial
populations and coastal seawater from the Great
Barrier Reef. The half-life for glyphosate at
25 C in low-light was 47 days, extending
to 267 days in the dark at 25 C and
315 days in the dark at 31 C, which is
the longest persistence reported for this herbicide.
AMPA, the microbial transformation product of
glyphosate, was detected under all conditions,
confirming that degradation was mediated by the
native microbial community. This study demonstrates
glyphosate is moderately persistent in the marine
water under low light conditions and is highly
persistent in the dark. Little degradation would be
expected during flood plumes in the tropics, which
could potentially deliver dissolved and
sediment-bound glyphosate far from shore.
88. Love, Bradley J, Einheuser, Matthew
D., Nejadhashemi, A. Pouyan, Effects on aquatic and human
health due to large scale bioenergy crop expansion.Sci Total
Environ. 2011 Aug 1 ;409(17):3215-29. Abstract: In this
study, the environmental impacts of large scale
bioenergy crops were evaluated using the Soil and
Water Assessment Tool (SWAT). Daily pesticide
concentration data for a study area consisting of
four large watersheds located in Michigan (totaling
53,358km(2)) was estimated over a six year period
(2000-2005). Model outputs for atrazine, bromoxynil,
glyphosate, metolachlor, pendimethalin, sethoxydim,
triflualin, and 2,4-D model output were used to
predict the possible long-term implications that
large-scale bioenergy crop expansion may have on the
bluegill (Lepomismacrochirus) and humans. Threshold
toxicity levels were obtained for the bluegill and
for human consumption for all pesticides being
evaluated through an extensive literature review.
Model output was compared to each toxicity level for
the suggested exposure time (96-hour for bluegill
and 24-hour for humans). The results suggest that
traditional intensive row crops such as canola, corn
and sorghum may negatively impact aquatic life, and
in most cases affect the safe drinking water
availability. The continuous corn rotation, the most
representative rotation for current agricultural
practices for a starch-based ethanol economy,
delivers the highest concentrations of glyphosate to
the stream. In addition, continuous canola
contributed to a concentration of 1.11ppm of
trifluralin, a highly toxic herbicide, which is 8.7
times the 96-hour ecotoxicity of bluegills and 21
times the safe drinking water level. Also during the
period of study, continuous corn resulted in the
impairment of 541,152km of stream. However, there is
promise with second-generation lignocellulosic
bioenergy crops such as switchgrass, which resulted
in a 171,667km reduction in total stream length that
exceeds the human threshold criteria, as compared to
the base scenario. Results of this study may be
useful in determining the suitability of bioenergy
crop rotations and aid in decision making regarding
the adaption of large-scale bioenergy cropping
systems. 89. Battaglin WA, Meyer MT,
Kuivila KM, and Dietze JE. Glyphosate and Its
Degradation Product AMPA Occur Frequently and Widely
in U.S. Soils, Surface Water, Groundwater, and
Precipitation. Journal of the
American Water Resources Association (JAWRA) 2014,
50, 275-290. Abstract: Looking
at
a wide range of geographical locations, researchers
from the US Geological Survey (USGS) analyzed 3732
water and sediment samples and 1081 quality
assurance samples collected between 2001 and 2010
from 38 states in the US and the district of
Columbia. They found glyphosate in 39.4 % of samples
(1470 out of 3732) and its metabolite AMPA
(α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic
acid) in 55% of samples. Water samples included
streams, groundwater, ditches and drains, large
rivers, soil water, lakes, ponds and wetlands,
precipitation, soil and sediment, and waste water
treatment plants. 90. Battaglin, W.A.; Kolpin, D.W.;
Scribner, E.A.; Kuivila, K.M.; Sandstrom, M.W. Glyphosate, other herbicides,
and transformation products in midwestern streams,
2002. J.
Am. Water Resour. Assoc2005, 41,
323332. Abstract: The use of glyphosate has increased
rapidly, and there is limited understanding of its
environmental fate. The objective of this study was
to document the occurrence of glyphosate and the
transformation product minomethylphosphonic acid
(AMPA) in Midwestern streams and to compare their
occurrence with that of more commonly measured
herbicides such as acetochlor, atrazine, and
metolachlor. Water samples were collected at sites
on 51 streams in nine Midwestern states in 2002
during three runoff events: after the application of
pre-emergence herbicides, after the application of
post-emergence herbicides, and during harvest
season. All samples were analyzed for glyphosate and
20 other herbicides using gas chromatography/mass
spectrometry or high performance liquid
chromatography/mass spectrometry. The frequency of
glyphosate and AMPA detection, range of
concentrations in runoff samples, and ratios of AMPA
to glyphosate concentrations did not vary throughout
the growing season as substantially as for other
herbicides like atrazine, probably because of
different seasonal use patterns. Glyphosate was
detected at or above 0.1 μg/l in 35 percent of
pre-emergence, 40 percent of post-emergence, and 31
percent of harvest season samples, with a maximum
concentration of 8.7 μg/l. AMPA was detected at or
above 0.1 μg/l in 53 percent of pre-emergence, 83
percent of post-emergence, and 73 percent of harvest
season samples, with a maximum concentration of 3.6
μg/l. Glyphosate was not detected at a concentration
at or above the U.S. Environmental Protection
Agencys maximum contamination level (MCL) of 700
μg/l in any sample. Atrazine was detected at or
above 0.1 μg/l in 94 percent of pre-emergence, 96
percent of post-emergence, and 57 percent of harvest
season samples, with a maximum concentration of 55
μg/l. Atrazine was detected at or above its MCL (3
μg/l) in 57 percent of pre-emergence and 33 percent
of post-emergence samples. 91. Sasal, M.C. et al,
Glyphosate loss by runoff and its relationship with
phosphorus fertilization. Journal of
Agriculture and Food Chemistry, 2015 May
13;63(18):4444-8. Abstract: The aim
of this study was to evaluate the relationship
between glyphosate and phosphate fertilizer
application and their contribution to surface water
runoff contamination. The study was performed in
AquicArgiudoll soil (Tezanos Pinto series). Four
treatments were assessed on three dates of rainfall
simulation after fertilizer and herbicide
application. The soluble phosphorus in runoff water
was determined by a colorimetric method. For the
determination of glyphosate and
aminomethylphosphonic acid (AMPA), a method based on
fluorenylmethyloxycarbonyl (FMOC) group
derivatization, solid phase extraction (SPE)
purification, and ultrahigh-performance liquid
chromatography-tandem mass spectrometry
(UHPLC-MS/MS) was employed. The application of
phosphorus fertilizer resulted in an increased loss
of glyphosate by runoff after 1 day of application.
These results suggest the need for further study to
understand the interactions and to determine
appropriate application timing with the goal of
reducing the pollution risk by runoff.
92. Jain ,
Sunil, Sharma, Dr. Gunwant, Mathur, Dr. Y.P. Effects
of Pesticides on hormone and enzyme systems of aqua
population: a view over Anasagar lake, Ajmer, IOSR Journal
Of Environmental Science, Toxicology And Food
Technology (IOSR)
Volume 1, Issue 5 (Nov. -Dec. 2012), PP
24-28. Abstract: Water
sources are particularly at risk to contamination by
pesticides because of the accumulation and
distribution of contaminating substances in
sediments of rivers, lakes, and ponds. Potential
sources of this impact in water bodies include
municipal sewage and agricultural runoff (pesticides
and herbicides). The enzyme and hormone disrupting
capabilities of pesticides and related chemicals are
suspected to be some of the factors contributing to
the decline of fish, amphibian and reptile
populations of water bodies. In most cases the cause
are assumed to result from man-made pollutants in
the aquatic environment. The lake Anasagar is a
perennial, shallow fresh wetland situated in the
heart of Ajmercity. It is degraded because of
anthropogenic activities including input of
detergents, pesticides and other chemicals due to
agricultural activities, sewage disposal and human
settlement around the lake. A large area of the
catchment of Lake Anasagar is being used for
agriculture particularly Trapabispinosa as the
primary cash crop and vegetable crops such as
Cauliflower, Tomato, Cabbage, Brinjal, Okra etc
.leading to input of organo chlorine pesticides in
the Lake. It
has been indicated that many pesticides in the
aquatic environment are capable of disrupting the
endocrine systems of aqua life. Some pesticides and
related chemicals are persistent in the environment
and are accumulated in the fatty tissue of organisms
and increase in concentration as they move up
through the food web. These chemicals are substances
that can cause adverse effects by interfering in
some way with the bodys hormones or chemical
messengers and even disrupting the sexual
development of aqua population even at extremely low
doses ,reducing the cholinesterase activity of
amphibians and reptiles, causing disease and
reproductive failure in fish populations. Concern
over the decline of amphibians globally has
highlighted the importance of using this group as a
bioindicator of environmental contamination and
climate change. 93. Laetz,
CathyA. et al., The Synergistic Toxicity of
Pesticide Mixtures: Implications for Risk Assessment
and the Conservation of Endangered, Pacific Salmon Environmental
Health Perspectives 117, No.3 (March
2009) 348-53. Abstract: Mixtures of organophosphate
and carbamate pesticides are commonly detected in
freshwater habitats that support threatened and
endangered species of Pacific salmon (Oncorhynchus
sp.). These pesticides inhibit the activity of
acetylcholinesterase (AChE) and thus have potential
to interfere with behaviors that may be essential
for salmon survival. Although the effects of
individual anticholin-esterase insecticides on
aquatic species have been studied for decades, the
neurotoxicity of mixtures is still poorly
understood. We assessed whether chemicals in a
mixture act in isolation (resulting in additive AChE
inhibition) or whether components interact to
produce either antagonistic or synergistic toxicity.
We measured brain AChE inhibition in juvenile coho
salmon (Oncorhynchuskisutch) exposed to sublethal
concentrations of the organophosphates diazinon,
malathion, and chlorpyrifos, as well as the
carbamatescarbaryl and carbofuran. Concentrations of
individual chemicals were normalized to their
respective median effective concentrations (EC50)
and collectively fit to a nonlinear regression. We
used this curve to determine whether toxicologic
responses to binary mixtures were additive,
antagonistic, or synergistic. We observed addition
and synergism, with a greater degree of synergism at
higher exposure concentrations. Several combinations
of organophosphates were lethal at concentrations
that were sublethal in single-chemical
trials.Single-chemical risk assessments are likely
to underestimate the impacts of these insecticides
on salmon in river systems where mixtures occur.
Moreover, mixtures of pesticides that have been
commonly reported in salmon habitats may pose a more
important challenge for species recovery than
previously anticipated. 94. Birch
H., Mikkelson P.S., Jenson J.K and Ltzhft, 2011.
Micropollutants in stormwater runoff and combined
sewer overflow in the Copenhagen area, Denmark. Water Science
and Technology64:485-493. Abstract: Stormwater runoff contains a
broad range of micropollutants. In Europe a number
of these substances are regulated through the Water
Framework Directive, which establishes Environmental
Quality Standards (EQSs) for surface waters.
Knowledge about discharge of these substances
through stormwater runoff and combined sewer
overflows (CSOs) is essential to ensure compliance
with the EQSs. Results from a screening campaign
including more than 50 substances at four storm
water discharge locations and one CSO in Copenhagen
are reported here. Heavy metal concentrations were
detected at levels similar to earlier findings,
e.g., with copper found at concentrations up to 13
times greater than the Danish standard for surface
waters. The concentration of polyaromatic
hydrocarbons (PAHs) exceeded the EQSs by factors up
to 500 times for storm water and 2,000 times for the
CSO. Glyphosate was found in all samples whilst
diuron, isoproturon, terbutylazine and MCPA were
found only in some of the samples.
Diethylhexylphthalate (DEHP) was also found at all
five locations in concentrations exceeding the EQS.
The results give a valuable background for designing
further monitoring programmes focusing on the
chemical status of surface waters in urban areas 95. Villeneuve
A., Larroud S &HumbertJF., 2011.
Herbicide contamination of freshwater ecosystems:
impact on microbial communities. In:
Pesticides Formulations, Effects,
Fate.Stoytcheva M. (Ed.) pp. 285-312, In Tech Abstract: In
France, the InstitutFranais de lEnvironnement
(French Institute for Environment; now known as the
Service de lObservationet des Statistiques, SOeS)
has published data on the contamination of water by
pesticides for every year since 1998. Their annual
report is based on monitoring 453 pesticides at 2023
sampling points (groundwater and rivers). In 2007,
pesticides were detected at almost 91% of the
sampling points, but usually at mean annual
concentrations of <0.5 μg/L. The highest
concentrations were found in regions with intensive
agriculture (South-West, Center-North and North of
France) and the lowest in regions (South-East and
South of Massif Central) characterized by less
intensive agriculture or by the presence of large
areas of natural environments. The pesticide most
often detected in French streams was AMPA
(aminomethylphosphonic acid), which is the primary
degradation product of glyphosate. There is a lot of
data is available about the contamination of
freshwater ecosystems by herbicides and also on the
direct or indirect impact of these compounds on
microbial communities living in these ecosystems.
These compounds appear to affect the structure and
composition of these communities, and also the
metabolism of the microorganisms involved. It is
very difficult to evaluate the consequences of such
changes on the whole functioning of freshwater
ecosystems, but there can be no doubt that it is
significantly affected by herbicide contamination,
because microbial communities play a key role in
these ecosystems. This impact is probably reinforced
by the fact that freshwater ecosystems are
simultaneously subjected to other selective
pressures. For example, herbicide pollution is
generally concomitant with pollution by mineral
nutrients (phosphorus and nitrogen), which also
influence the structure and the functioning of
microbial communities. 96. Borggaard,
O.K.; and A.L. Gimsing(2008). Fate
of glyphosate in soil and the possibility of
leaching to ground and surface waters: A review. Abstract: The very wide use of
glyphosate to control weeds in agricultural,
silvicultural and urban areas throughout the world
requires that special attention be paid to its
possible transport from terrestrial to aquatic
environments. The aim of this review is to present
and discuss the state of knowledge on sorption,
degradation and leachability of glyphosate in soils.
Difficulties of drawing clear and unambiguous
conclusions because of strong soil dependency and
limited conclusive investigations are pointed out.
Nevertheless, the risk of ground and surface water
pollution by glyphosate seems limited because of
sorption onto variable-charge soil minerals, e.g.
aluminum and iron oxides, and because of microbial
degradation. Although sorption and degradation are
affected by many factors that might be expected to
affect glyphosate mobility in soils, glyphosate
leaching seems mainly determined by soil structure
and rainfall. Limited leaching has been observed in
non-structured sandy soils, while subsurface
leaching to drainage systems was observed in a
structured soil with preferential flow in
macropores, but only when high rainfall followed
glyphosate application. Glyphosate in drainage water
runs into surface waters but not necessarily to
groundwater because it may be sorbed and degraded in
deeper soil layers before reaching the groundwater.
Although the transport of glyphosate from land to
water environments seems very limited, knowledge
about subsurface leaching and surface runoff of
glyphosate as well as the importance of this
transport as related to ground and surface water
quality is scarce. Pest
Management Science, 64:441456,
DOI:10.1002/ps.1512. Wildlife 97. Bergman,Ake,Heinde,
Jerrold J., Jobling , Susan, Kidd, Karen A.,
Zoeller, R. Thomas, State of
the Science of Endocrine Disrupting Chemicals, Inter-OrganisationProgramme
for
the Sound Management of Chemicals (IOMC), with The
Participating Organisations FAO, ILO, UNDP, UNEP,
UNIDO, UNITAR, WHO, World Bank and OECD, 2012, Excerpt: There is a worldwide loss of
species or reduced
population numbers of amphibians, mammals, birds,
reptiles, freshwater and marine fishes and
invertebrates. Endocrine Disruptor Chemicals have
been shown to negatively affect body systems that
are critical for the health and survival of
wildlife. The current body burdens of POPs such as
PCBs, organochlorine pesticides and methylmercury in
some fish-eating birds and marine mammal populations
are at levels known to cause effects on breeding and
on the immune system some of these populations are
threatened or endangered. Legal, technical and
ethical constraints to working with wildlife,
notably those listed under endangered species
legislation, prevent research to investigate
chemical causes of population declines in these
animals. An increasing number of chemicals to which
wildlife are exposed have been shown to interfere
with the hormonal and immune systems of wildlife
species. Most of these chemicals are not monitored
in ecosystems. Exposed wildlife populations are
often not monitored either. Experimental animal
studies have shown that many chemicals can interfere
with the development and function of endocrine
systems, leading to effects on behaviour, fecundity,
growth, survival and disease resistance. This
increases the probability that exposure to EDCs
could lead to population-level effects in wildlife. Butterflies 98. Pleasants J.N.
and Oberhauser K.S.,
2012.Milkweed loss in agricultural fields because
of herbicide use: effect on the monarch butterfly
population.
Insect Conservation and Diversity Volume
6, Issue 2, 135144,
March 2013, Abstract: The size of the Mexican overwintering
population of monarch butterflies has decreased over
the last decade. Approximately half of these
butterflies come from the U.S. Midwest where larvae
feed on common milkweed. There has been a large
decline in milkweed in agricultural fields in the
Midwest over the last decade. This loss is
coincident with the increased use of glyphosate
herbicide in conjunction with increased planting of
genetically modified (GM) glyphosate-tolerant corn
(maize) and soybeans (soya). We
investigate whether the decline in the size of the
overwintering population can be attributed to a decline
in monarch production owing to a loss of milkweeds
in agricultural fields in the Midwest. We estimate
Midwest annual monarch production using data on the
number of monarch eggs per milkweed plant for
milkweeds in different habitats, the density of
milkweeds in different habitats, and the area
occupied by those habitats on the landscape. We
estimate that there has been a 58% decline in
milkweeds on the Midwest landscape and an 81%
decline in monarch production in the Midwest from
1999 to 2010. Monarch production in the Midwest each
year was positively correlated with the size of the
subsequent overwintering population in Mexico. Taken
together, these results strongly suggest that a loss
of agricultural milkweeds is a major contributor to
the decline in the monarch population. The smaller
monarch population size that has become the norm
will make the species more vulnerable to other
conservation threats.
Honeybees 99. Mao, W.; Schuler, M.A.;
Berenbaum, M.R.
CYP9Q-mediated detoxification of acaricides in the
honey bee (Apismellifera).
Proc.
Natl. Am. Soi. 2011, 108,
1265712662. Abstract: Although Apismellifera, the
western honey bee, has long encountered pesticides
when foraging in agricultural fields, for two
decades it has encountered pesticides in-hive in the
form of acaricides to control Varroa destructor, a
devastating parasitic mite. The pyrethroid
tau-fluvalinate and the organophosphate coumaphos
have been used for Varroa control, with little
knowledge of honey bee detoxification mechanisms.
Cytochrome P450-mediated detoxification contributes
to pyrethroid tolerance in many insects, but
specific P450s responsible for pesticide
detoxification in honey bees (indeed, in any
hymenopteran pollinator) have not been defined. We
expressed and assayed CYP3 clan midgut P450s and
demonstrated that CYP9Q1, CYP9Q2, and CYP9Q3
metabolize tau-fluvalinate to a form suitable for
further cleavage by the carboxylesterases that also
contribute to tau-fluvalinate tolerance. These in
vitro assays indicated that all of the three CYP9Q
enzymes also detoxify coumaphos. Molecular models
demonstrate that coumaphos and tau-fluvalinate fit
into the same catalytic pocket, providing a possible
explanation for the synergism observed between these
two compounds. Induction of CYP9Q2 and CYP9Q3
transcripts by honey extracts suggested that
diet-derived phytochemicals may be natural
substrates and heterologous expression of CYP9Q3
confirmed activity against quercetin, a flavonoid
ubiquitous in honey. Up-regulation by honey
constituents suggests that diet may influence the
ability of honey bees to detoxify pesticides.
Quantitative RT-PCR assays demonstrated that
tau-fluvalinate enhances CYP9Q3 transcripts, whereas
the pyrethroidbifenthrin enhances CYP9Q1 and CYP9Q2
transcripts and represses CYP9Q3 transcripts. The
independent regulation of these P450s can be useful
for monitoring and differentiating between pesticide
exposures in-hive and in agricultural fields. 100. Foulk,
K.E.; Reeves, C.
Identifying the role of glyphosate-containing
herbicides on honeybee mortality rates and colony
collapse disorder. In Proceedings
of Junior Science, Engineering, and Humanities
Symposium, Camdenton, MO, USA, 2009; 223. Abstract: Samples of bees and honey of hives from
colonies that have and have not been affected by
Colony Collapse Disorder were collected from
beekeepers located throughout the State of Missouri.
These samples were analyzed using a
liquid-chromatography mass spectrometer to detect
traces of glyphosate and its metabolite
aminomethylphosphonic acid. Nine hives, built
according to a design described by Dr. Marion Ellis
of the University of Nebraska-Lincoln, were filled
with bees, and the nine hives were divided into
three groups of three hives each. Each group was fed
one of the following: sugar water, sugar water with
glyphosate, or sugar water with Roundup QuikPro.
The amount of glyphosate added was based on a study
performed by Blackburn and Boutin (2003). All hives
were kept in a dark, humidified room located in the
science department in Camdenton High School,
Camdenton, MO. Data on mortality were collected and
subjected to a two-way Analysis of Variance (ANOVA).
Samples of bees and comb from each experimental hive
were analyzed using a liquid-chromatography mass
spectrometer (USGS Water Research Facility,
Lawrence, KS). The results of this study indicate
that the mortality rate of bees that were fed
glyphosate-supplemented diets, both pure glyphosate
and Roundup QuikPro, were significantly greater
than that of hives without glyphosate supplemented
diets (p < 0.001). 101.Balbuena, M.
S., L. Tison, M-L.Hahn, U. Greggers, R. Menzel,
and W. M. Farina (2015).Effects
of sublethal doses of glyphosate on honeybee navigation.
Abstract: Glyphosate (GLY) is a
herbicide that is widely used in agriculture for
weed control. Although reports about the impact of
GLY in snails, crustaceans and amphibians exist, few
studies have investigated its sublethal effects in
non-target organisms such as the honeybee Apis
mellifera, the main pollen vector in commercial
crops. Here, we tested whether exposure to three
sublethal concentrations of GLY (2.5, 5 and 10 mg
l(-1): corresponding to 0.125, 0.250 and 0.500 μg
per animal) affects the homeward flight path of
honeybees in an open field. We performed an
experiment in which forager honeybees were trained
to an artificial feeder, and then captured, fed with
sugar solution containing traces of GLY and released
from a novel site either once or twice. Their
homeward trajectories were tracked using harmonic
radar technology. We found that honeybees that had
been fed with solution containing 10 mg l(-1) GLY
spent more time performing homeward flights than
control bees or bees treated with lower
concentrations. They also performed more indirect
homing flights. Moreover, the proportion of direct
homeward flights performed after a second release
from the same site increased in control bees but not
in treated bees. These results suggest that, in
honeybees, exposure to levels of GLY commonly found
in agricultural settings impairs the cognitive
capacities needed to retrieve and integrate spatial
information for a successful return to the hive.
Therefore, honeybee navigation is affected by
ingesting traces of the most widely used herbicide
worldwide, with potential long-term negative
consequences for colony foraging success. Journal
of Experimental Biology, 218:2799-2805. 102.Herbert, L.T., D.E.
Vzquez, A. Arenas and W.M. Farina (2014). Effects of
field-realistic doses of glyphosate on honeybee
appetitive behavior. Abstract:
Glyphosate
(GLY) is a broad-spectrum herbicide used for weed
control. The sub-lethal impact of GLY on non-target
organisms such as insect pollinators has not yet
been evaluated. Apis mellifera is the main
pollinator in agricultural environments and is a
well-known model for behavioural research. Honeybees
are also accurate biosensors of environmental
pollutants and their appetitive behavioural response
is a suitable tool with which to test sub-lethal
effects of agrochemicals. We studied the effects of
field-realistic doses of GLY on honeybees exposed
chronically or acutely to the herbicide. We focused
on sucrose sensitivity, elemental and non-elemental
associative olfactory conditioning of the proboscis
extension response (PER), and foraging-related
behaviour. We found a reduced sensitivity to sucrose
and learning performance for the groups chronically
exposed to GLY concentrations within the range of
recommended doses. When olfactory PER conditioning
was performed with sucrose reward with the same GLY
concentrations (acute exposure), elemental learning
and short-term memory retention decreased
significantly compared with controls. Non-elemental
associative learning was also impaired by an acute
exposure to GLY traces. Altogether, these results
imply that GLY at concentrations found in
agro-ecosystems as a result of standard spraying can
reduce sensitivity to nectar reward and impair
associative learning in honeybees. However, no
effect on foraging-related behaviour was found.
Therefore, we speculate that successful forager bees
could become a source of constant inflow of nectar
with GLY traces that could then be distributed among
nestmates, stored in the hive and have long-term
negative consequences on colony performance. Journal
of
Experimental Biology, 217:3457-3464. Freshwater
Environment 103.Annetta, R., H. R.
Habibib and A. Hontela(2014). Impact of
glyphosate and glyphosate-based herbicides on the
freshwater environment. Journal of Applied
Toxicology 34:458-479. Abstract:
Glyphosate [N-(phosphonomethyl)
glycine] is a broad spectrum, post emergent
herbicide and is among the most widely used
agricultural chemicals globally. Initially developed
to control the growth of weed species in
agriculture, this herbicide also plays an important
role in both modern silviculture and domestic weed
control. The creation of glyphosate tolerant crop
species has significantly
increased the demand and use of this herbicide and
has also increased the risk of exposure to
non-target species. Commercially available
glyphosate-based herbicides are comprised of
multiple, often proprietary, constituents, each with
a unique level of toxicity. Surfactants used to
increase herbicide efficacy
have been identified in some
studies as the chemicals responsible for toxicity of
glyphosate-based herbicides to non-target species,
yet they are often difficult to
chemically identify. Most glyphosate-based
herbicides are not approved for use in the aquatic
environment; however, measurable quantities of the
active ingredient and surfactants are detected in
surface waters, giving them the potential to alter
the physiology of aquatic organisms. Acute toxicity
is highly species dependent across all taxa, with
toxicity depending on the timing, magnitude, and
route of exposure. The toxicity of glyphosate to
amphibians has been a major focus of recent
research, which has suggested increased sensitivity
compared with other vertebrates due to their life
history traits and reliance on both the aquatic and
terrestrial environments. This review is designed to
update previous reviews of glyphosate-based
herbicide toxicity, with a focus on recent studies
of the aquatic toxicity of this class of chemicals. 104.Arunakumara,
K. I. U., B. C. Walpola and M. Yoon (2013). Metabolism
and degradation of glyphosate in aquatic
cyanobacteria: A review. African Journal of
Microbiology Research, 7(32):4084-4090. Abstract: Use of glyphosate (N-phosphonomethylglycine), a
broad-spectrum, non-selective, post-emergence
herbicide has been increased steadily
with the introduction of genetically
modified glyphosate-resistant crops. Increased
reliance on herbicides for suppressing weeds and
aggressive marketing have also contributed
substantially to rising demand for glyphosate.
Degradation of glyphosate was basically done by soil
microorganisms; however, once the herbicide reached
to the aquatic systems, cyanobacterial strains were
reported to be involved in the process of
biodegradation. Upon glyphosate exposure, a
remarkable tolerance was reported in many strains,
where cell proliferation was found to be completely
unaffected by the herbicide at
the concentration of micromolar to
millimolar range. However, the mechanism through
which cyanobacteria exhibit the tolerance seemed to
be widely varied and species-dependent.
Carrier-independent uptake of glyphosate has
been suggested as the resistance mechanism at
micromolar level concentrations. Presence of
resistant form of the target enzyme
EPSP (5-enolpyruvylshikimate-3-phosphate) and
the ability of some strains to metabolize glyphosate
have also been reported to be responsible for the
tolerance. A remarkable ability to degrade
glyphosate has been identified from some
cyanobacterial strains such as Spirulina spp.
where degradative pathway was however
reported to be different from those exhibited
in other bacteria. Exploitation of
cyanobacteria in biological treatments of waste
water contaminated with glyphosate has not yet been
reported, mainly due to lack of research evidence on
as to how cyanobacteria deal with biodegradation of
glyphosate under field conditions. 105.Vera
M.S. et al (2012).
Direct and indirect effects of the glyphosate
formulation GlifosatoAtanor on freshwater microbial
communities.EcotoxicologyVol
21 pp 1805-16. Abstract: Glyphosate-based
formulations are among the most widely used
herbicides in the world. The effect of the
formulation GlifosatoAtanor() on freshwater
microbial communities (phytoplankton,
bacterioplankton, periphyton and zooplankton) was
assessed through a manipulative experiment using six
small outdoor microcosms of small volume. Three of
the microcosms were added with 3.5 mg l(-1) of
glyphosate whereas the other three were left as
controls without the herbicide. The treated
microcosms showed a significant increase in total
phosphorus, not fully explained by the glyphosate
present in the GlifosatoAtanor(). Therefore, part
of the phosphorus should have come from the
surfactants of the formulation. The results showed
significant direct and indirect effects of
GlifosatoAtanor() on the microbial communities. A
single application of the herbicide caused a fast
increase both in the abundance of bacterioplankton
and planktonic picocyanobacteria and in chlorophyll
a concentration in the water column. Although
metabolic alterations related to oxidative stress
were induced in the periphyton community, the
herbicide favored its development, with a large
contribution of filamentous algae typical of
nutrient-rich systems, with shallow and calm waters.
An indirect effect of the herbicide on the
zooplankton was observed due to the increase in the
abundance of the rotifer Lecane spp. as a
consequence of the improved food availability given
by picocyanobacteria and bacteria. The formulation
affected directly a fraction of copepods as a
target. It was concluded that the GlifosatoAtanor()
accelerates the deterioration of the water quality,
especially when considering small-volume water
systems. 106.Mensah, P.K. W.J. Muller,
C.G. Palmer (2011). Acute toxicity of
Roundup herbicide to three life stages of the
freshwater shrimp Caridinanilotica
(Decapoda: Atyidae). Abstract:
Glyphosate
based herbicides, including Roundup, are frequently
used in the chemical control of weeds and invading
alien plant species in South Africa. These
herbicides ultimately get into water courses
directly or indirectly through processes such as
drifting, leaching, surface runoff and foliar spray
of aquatic nuisance plants. Despite their widespread
use, no water quality guideline exists to protect
indigenous South African freshwater organisms from
the toxic effects of these herbicides. The toxicity
of the herbicide Roundup was assessed using three
different life stages of the freshwater shrimp Caridina
nilotica, a prevalent species in South
African freshwater ecosystems. Neonate
(<7 days post hatching (dph)), juvenile
(>7 dph and <20 dph) and adult
(>40 dph) shrimps were exposed to varying
concentrations (1.550 mg/L acid equivalence
(a.e.)) of the herbicide in 48 and 96 h acute
toxicity tests in order to determine the most
sensitive life-stage. The results showed neonates to
be more sensitive to Roundup than both juveniles
and adults with mean 96 h LC50
values of 2.5, 7.0 and 25.3 mg/L a.e.
respectively. The estimated 96 h LC50
of neonates is much lower than the application rate
(2030 mg/L a.e.), although the
applications impact will depend on the dilution
rate of the applied concentration in the
environment. All three life-stages of unexposed
animals exhibited active and coordinated movement
but exposed shrimps were erratic and slow in their
movements, with neonates showing most of these
behavioral irregularities. This study shows that low
levels of the herbicide Roundup may adversely
affect C. nilotica health and survival.
Thus, the herbicide should be carefully managed to
minimize any negative impact on non-target
freshwater organisms. Physics
and chemistry of the Earth, 36:905-909. 107. Perez,
G.L., A. Torremorell, H. Mugni, P. Rodriguez, M.S.
Vera, M. Nascimento, L. Allende, J. Bustingorry,
R. Escaray, M. Ferraro (2007). Effects of the herbicide Roundup on
freshwater microbial communities: A mesocosm study
. Abstract: The impact of the widely
used herbicide glyphosate has been mainly studied in
terrestrial weed control, laboratory bioassays, and
field studies focusing on invertebrates, amphibians,
and fishes. Despite the importance of phytoplankton
and periphyton communities at the base of the
aquatic food webs, fewer studies have investigated
the effects of glyphosate on freshwater microbial
assemblages. We assessed the effect of the
commercial formulation Roundup using artificial
earthen mesocosms. The herbicide was added at three
doses: a control (without Roundup) and two
treatments of 6 and 12 mg/L of the active ingredient
(glyphosate). Estimates of the dissipation rate (k)
were similar in the two treatments (half-lives of
5.77 and 7.37 d, respectively). The only two
physicochemical parameters showing statistically
significant differences between treatments and
controls were the downward vertical spectral
attenuation coefficient kd(λ),
where λ is wavelength, and total phosphorus
concentration (TP). At the end of the experiment,
the treated mesocosms showed a significant increase
in the ratio kd(490 nm)/kd(550
nm) and an eightfold increase in TP. Roundup
affected the structure of phytoplankton and
periphyton assemblages. Total micro- and
nanophytoplankton decreased in abundance in treated
mesocosms. In contrast, the abundance of
picocyanobacteria increased by a factor of about 40.
Primary production also increased in treated
mesocosms (roughly by a factor of two). Similar
patterns were observed in the periphytic
assemblages, which showed an increased proportion of
dead : live individuals and
increased abundances of cyanobacteria (about
4.5-fold). Interestingly, the observed changes in
the microbial assemblages were captured by the
analysis of the pigment composition of the
phytoplankton, the phytoplankton absorption spectra,
and the analysis of the optical properties of the
water. The observed changes in the structure of the
microbial assemblages are more consistent with a
direct toxicological effect of glyphosate rather
than an indirect effect mediated by phosphorus
enrichment.. Ecological
Applications, 17(8): 23102322. 108.Romero,
D.M., M.C.R. de Molina, and A.B. Juarez (2011).
Oxidative
stress induced by a commercial glyphosate
formulation in a tolerant strain of Chlorella
kessleri (algae). Abstract: We studied the toxicity of a
glyphosate formulation and provide evidence of
metabolic alterations due to oxidative stress caused
in a Chlorella kessleri tolerant strain by exposure
to the herbicide. After 96 h of exposure to
increasing concentrations of the herbicide (0-70 mg
L(-1)) with alkylaryl polyglycol ether surfactant,
growth was inhibited (EC50-96 h 55.62 mg L(-1)).
Glyphosate increased protein and malondialdehyde
content which was significantly higher than in the
control at 50-70 mg L(-1). Superoxide dismutase and
catalase activities and reduced glutathione levels
increased in a concentration-dependant manner.
Morphological studies showed increases in
vacuolisation and in cell and sporangia sizes. The
glyphosate formulation studied has a cytotoxic
effect on C. kessleri through a mechanism that would
involve the induction of oxidative stress. Upon
glyphosate exposure, oxidative stress parameters
such as SOD and CAT activities and MDA level could
be more sensitive biomarkers than usually tested
growth parameters in C. kessleri Ecotoxicology
and Environmental Safety, 74(4):741747. 4. The Need for New Regulatory
Action 109.Colburn, Theo, A case for revisiting the safety of pesticides: a closer look at neurodevelopment Environ Health Persp. 2006 Jan;114(1):10-17 Abstract: The quality and quantity of the data about the risk posed to humans by individual pesticides vary considerably. Unlike obvious birth defects, most developmental effects cannot be seen at birth or even later in life. Instead, brain and nervous system disturbances are expressed in terms of how an individual behaves and functions, which can vary considerably from birth through adulthood. In this article I challenge the protective value of current pesticide risk assessment strategies in light of the vast numbers of pesticides on the market and the vast number of possible target tissues and end points that often differ depending upon timing of exposure. Using the insecticide chlorpyrifos as a model, I reinforce the need for a new approach to determine the safety of all pesticide classes. Because of the uncertainty that will continue to exist about the safety of pesticides, it is apparent that a new regulatory approach to protect human health is needed. |