Evaluation of DNA damage in an Ecuadorian population exposed to glyphosate

The effect of acute exposure of yellowtail tetra fish Astyanax lacustris (Lütken, 1875) to the glyphosate-based herbicide Templo®

The herbicide glyphosate (N-(phosphonomethyl)glycine) efficiently eliminates weeds, is frequently present in surface waters, and may damage the health of various non-target organisms. The main objective of this study was to investigate cytotoxic and genotoxic effects in erythrocytes, DNA, and chromosomes of native South American fish Astyanax lacustris exposed to a glyphosate-based commercial herbicide Templo®. The presenty study evaluated the presence of micronuclei (MN), chromosomal aberrations (CA), DNA damage revealed by comet assay, and cellular morphological changes (CMC) as biomarkers. The A. lacustris specimens were exposed to Templo® for 96 h at concentrations below the permitted Brazilian legislation for freshwater environments. The glyphosate-based herbicide caused MN formation, an increased incidence of CA, DNA damage, and several types of CMC in all tested concentrations on A. lacustris. Notably, analyses were significant (p<0.05) for all concentrations, except in the frequency mean of MN at 3.7 µg/L. Thus, considering the intensive use of commercial glyphosate formulations in crops, the herbicide Templo® represents a potential risk of genotoxicity and cytotoxicity for aquatic organisms. Therefore, environmental protection agencies must review regulations for glyphosate-based herbicides in freshwater environments.

Glyphosate Use and Mosaic Loss of Chromosome Y among Male Farmers in the Agricultural Health Study

BACKGROUND

Glyphosate is the most commonly used herbicide worldwide and has been implicated in the development of certain hematologic cancers. Although mechanistic studies in human cells and animals support the genotoxic effects of glyphosate, evidence in human populations is scarce.

OBJECTIVES

We evaluated the association between lifetime occupational glyphosate use and mosaic loss of chromosome Y (mLOY) as a marker of genotoxicity among male farmers.

METHODS

We analyzed blood-derived DNA from 1,606 farmers ≥ 50 years of age in the Biomarkers of Exposure and Effect in Agriculture study, a subcohort of the Agricultural Health Study. mLOY was detected using genotyping array intensity data in the pseudoautosomal region of the sex chromosomes. Cumulative lifetime glyphosate use was assessed using self-reported pesticide exposure histories. Using multivariable logistic regression, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between glyphosate use and any detectable mLOY (overall mLOY) or mLOY affecting ≥ 10 % of cells (expanded mLOY).

RESULTS

Overall, mLOY was detected in 21.4% of farmers, and 9.8% of all farmers had expanded mLOY. Increasing total lifetime days of glyphosate use was associated with expanded mLOY [highest vs. lowest quartile; OR = 1.75 (95% CI: 1.00, 3.07), p trend = 0.03 ] but not with overall mLOY; the associations with expanded mLOY were most apparent among older (≥ 70 years of age) men [OR = 2.30 (95% CI: 1.13, 4.67), p trend = 0.01 ], never smokers [OR = 2.32 (95% CI: 1.04, 5.21), p trend = 0.04 ], and nonobese men [OR = 2.04 (95% CI: 0.99, 4.19), p trend = 0.03 ]. Similar patterns of associations were observed for intensity-weighted lifetime days of glyphosate use.

DISCUSSION

High lifetime glyphosate use could be associated with mLOY affecting a larger fraction of cells, suggesting glyphosate could confer genotoxic or selective effects relevant for clonal expansion. As the first study to investigate this association, our findings contribute novel evidence regarding the carcinogenic potential of glyphosate and require replication in future studies. https://doi.org/10.1289/EHP12834.

Mapping the key characteristics of carcinogens for glyphosate and its formulations: A systematic review

Glyphosate was classified as a probable human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC) partially due to strong mechanistic evidence in 2015. Since then, numerous studies of glyphosate and its formulations (GBF) have emerged. These studies can be evaluated for cancer hazard identification with the newly described ten key characteristics (KC) of carcinogens approach. Our objective was to assess all in vivo, ex vivo, and in vitro mechanistic studies of human and experimental animals (mammals) that compared exposure to glyphosate/GBF with low/no exposure counterparts for evidence of the ten KCs. A protocol with our methods adhering to PRISMA guidelines was registered a priori (INPLASY202180045). Two blinded reviewers screened all in vivo, ex vivo, and in vitro studies of glyphosate/GBF exposure in humans/mammals reporting any KC-related outcome available in PubMed before August 2021. Studies that met inclusion criteria underwent data extraction conducted in duplicate for each KC outcome reported along with key aspects of internal/external validity, results, and reference information. These data were used to construct a matrix that was subsequently analyzed in the program R to conduct strength of evidence and quality assessments. Of the 2537 articles screened, 175 articles met inclusion criteria, from which we extracted >50,000 data points related to KC outcomes. Data analysis revealed strong evidence for KC2, KC4, KC5, KC6, KC8, limited evidence for KC1 and KC3, and inadequate evidence for KC7, KC9, and KC10. Notably, our in-depth quality analyses of genotoxicity (KC2) and endocrine disruption (KC8) revealed strong and consistent positive findings. For KC2, we found: 1) studies conducted in humans and human cells provided stronger positive evidence than counterpart animal models; 2) GBF elicited a stronger effect in both human and animal systems when compared to glyphosate alone; and 3) the highest quality studies in humans and human cells consistently revealed strong evidence of genotoxicity. Our analysis of KC8 indicated that glyphosate's ability to modulate hormone levels and estrogen receptor activity is sensitive to both exposure concentration and formulation. The modulations observed provide clear evidence that glyphosate interacts with receptors, alters receptor activation, and modulates the levels and effects of endogenous ligands (including hormones). Our findings strengthen the mechanistic evidence that glyphosate is a probable human carcinogen and provide biological plausibility for previously reported cancer associations in humans, such as non-Hodgkin lymphoma. We identified potential molecular interactions and subsequent key events that were used to generate a probable pathway to lymphomagenesis.

Glyphosate exposure and urinary oxidative stress biomarkers in the Agricultural Health Study

BACKGROUND

Glyphosate is the most widely applied herbicide worldwide, and its use has been associated with increased risks of certain hematopoietic cancers in epidemiologic studies. Animal and in vitro experiments suggest that glyphosate may induce oxidative stress, a key characteristic of carcinogens; however, evidence in human populations remains scarce. We investigated associations between glyphosate exposure and urinary oxidative stress biomarkers in the Biomarkers of Exposure and Effect in Agriculture study, a molecular epidemiologic subcohort in the Agricultural Health Study.

METHODS

This analysis included 268 male farmers selected based on self-reported recent and lifetime occupational glyphosate use and 100 age- and geography-matched male nonfarmers. Concentrations of glyphosate and oxidative stress biomarkers (8-hydroxy-2'-deoxyguanosine [8-OHdG], 8-iso-prostaglandin-F2α, and malondialdehyde [MDA]) were quantified in first-morning-void urine. We performed multivariable linear regression to evaluate associations of urinary glyphosate and self-reported glyphosate use with each oxidative stress biomarker.

RESULTS

Urinary glyphosate concentrations were positively associated with levels of 8-OHdG (highest vs lowest glyphosate quartile; geometric mean ratio = 1.15, 95% confidence interval = 1.03 to 1.28; Ptrend = .02) and MDA (geometric mean ratio = 1.20, 95% confidence interval = 1.03 to 1.40; Ptrend = .06) overall. Among farmers reporting recent glyphosate use (last 7 days), use in the previous day was also associated with statistically significantly increased 8-OHdG and MDA levels. Compared with nonfarmers, we observed elevated 8-iso-prostaglandin-F2α levels among farmers with recent, high past 12-month, or high lifetime glyphosate use.

CONCLUSIONS

Our findings contribute to the weight of evidence supporting an association between glyphosate exposure and oxidative stress in humans and may inform evaluations of the carcinogenic potential of this herbicide.

Glyphosate Toxicity: In Vivo, In Vitro, and Epidemiological Evidence

Glyphosate is the most applied agricultural chemical worldwide and has become nearly ubiquitous throughout the environment. Glyphosate is an effective herbicide because it disrupts the shikimate pathway, which is responsible for the synthesis of essential amino acids in plants and microorganisms. Given that there is no known target for glyphosate in higher animals, its toxicity to humans and other animals is heavily debated, especially after the 2015 IARC ruling that glyphosate is carcinogenic. Today, a growing body of literature shows in vitro, in vivo, and epidemiological evidence for the toxicity of glyphosate across animal species. With the application of glyphosate increasing globally, it is important to discuss these reports to enable a broader conversation on glyphosate toxicity and its impact on human and environmental health. Here, we summarize the recent glyphosate literature and discuss its implications.

Monitoring residues of pesticides in food in Brazil: A multiscale analysis of the main contaminants, dietary cancer risk estimative and mechanisms associated

Introduction

Pesticides pose a risk for cancer development and progression. People are continuously exposed to such substances by several routes, including daily intake of contaminated food and water, especially in countries that are highly pesticide consumers and have very permissive legislation about pesticide contamination as Brazil. This work investigated the relationship among pesticides, food contamination, and dietary cancer risk.

Methods

Analyzed two social reports from the Brazilian Government: the Program for Analysis of Residues of Pesticides in Food (PARA) and The National Program for Control of Waste and Contaminants (PNCRC).

Results and discussion

First, we characterized the main pesticide residues detected over the maximum limits allowed by legislation or those prohibited for use in food samples analyzed across the country. Based on this list, we estimated the dietary cancer risks for some of the selected pesticides. Finally, we searched for data about dietary cancer risks and carcinogenic mechanisms of each pesticide. We also provided a critical analysis concerning the pesticide scenario in Brazil, aiming to discuss the food contamination levels observed from a geographical, political, and public health perspective. Exposures to pesticides in Brazil violate a range of human rights when food and water for human consumption are contaminated.

The effect of low doses of chlorpyrifos on blood and bone marrow cells in Wistar rats

The aim of this study was to investigate the genotoxic potential of low doses of chlorpyrifos (CPF) on blood and bone marrow cells in adult male Wistar rats. CPF was administered by oral gavage at daily doses of 0.010, 0.015, and 0.160 mg/kg of body weight (bw) for 28 consecutive days. Positive control (PC) was administered 300 mg/kg bw/day of ethyl methane sulphonate (EMS) for the final three days of the experiment. Toxic outcomes of exposure were determined with the in vivo micronucleus (MN) assay and alkaline comet assay. The 28-day exposure to the 0.015 mg/kg CPF dose, which was three times higher than the current value of acute reference dose (ARfD), reduced body weight gain in rats the most. The in vivo MN assay showed significant differences in number of reticulocytes per 1000 erythrocytes between PC and negative control (NC) and between all control groups and the groups exposed to 0.015 and 0.160 mg/kg bw/day of CPF. The number of micronucleated polychromatic erythrocytes per 2000 erythrocytes was significantly higher in the PC than the NC group or group exposed to 0.015 mg/kg bw/day of CPF. CPF treatment did not significantly increase primary DNA damage in bone marrow cells compared to the NC group. However, the damage in bone marrow cells of CPF-exposed rats was much higher than the one recorded in leukocytes, established in the previous research. Both assays proved to be successful for the assessment of CPFinduced genome instability in Wistar rats. However, the exact mechanisms of damage have to be further investigated and confirmed by other, more sensitive methods.

The surfactant co-formulant POEA in the glyphosate-based herbicide RangerPro but not glyphosate alone causes necrosis in Caco-2 and HepG2 human cell lines and ER stress in the ToxTracker assay

The toxicity of co-formulants present in glyphosate-based herbicides (GBHs) has been widely discussed leading to the European Union banning the polyoxyethylene tallow amine (POEA). We identified the most commonly used POEA, known as POE-15 tallow amine (POE-15), in the widely used US GBH RangerPro. Cytotoxicity assays using human intestinal epithelial Caco-2 and hepatocyte HepG2 cell lines showed that RangerPro and POE-15 are far more cytotoxic than glyphosate alone. RangerPro and POE-15 but not glyphosate caused cell necrosis in both cell lines, and that glyphosate and RangerPro but not POE-15 caused oxidative stress in HepG2 cells. We further tested these pesticide ingredients in the ToxTracker assay, a system used to evaluate a compound's carcinogenic potential, to assess their capability for inducing DNA damage, oxidative stress and an unfolded protein response (endoplasmic reticulum, ER stress). RangerPro and POE-15 but not glyphosate gave rise to ER stress. We conclude that the toxicity resulting from RangerPro exposure is thus multifactorial involving ER stress caused by POE-15 along with oxidative stress caused by glyphosate. Our observations reinforce the need to test both co-formulants and active ingredients of commercial pesticides to inform the enactment of more appropriate regulation and thus better public and environmental protection.

Bioremediation potential of glyphosate-degrading microorganisms in eutrophicated Ecuadorian water bodies

Phosphonate compounds are the basis of many xenobiotic pollutants, such as Glyphosate (N-(phosphonomethyl-glycine). Only procaryotic microorganisms and the lower eukaryotes are capable of phosphonate biodegradation through C–P lyase pathways. Thus, the aim of this study was to determine the presence of C–P lyase genes in Ecuadorian freshwater systems as a first step towards assessing the presence of putative glyphosate degraders. To that end, two Nested PCR assays were designed to target the gene that codifies for the subunit J (phnJ), which breaks the C-P bond that is critical for glyphosate mineralization. The assays designed in this study led to the detection of phnJ genes in 7 out of 8 tested water bodies. The amplified fragments presented 85–100% sequence similarity with phnJ genes that belong to glyphosate-degrading microorganisms. Nine sequences were not reported previously in the GenBank. The presence of phosphonate degraders was confirmed by isolating three strains able to grow using glyphosate as a unique carbon source. According to the 16S sequence, these strains belong to the Pantoea, Pseudomonas, and Klebsiella genera. Performing a Nested PCR amplification of phnJ genes isolated from eutrophicated water bodies, prior to isolation, may be a cost-effective strategy for the bioprospection of new species and/or genes that might have new properties for biotech industries, laying the groundwork for additional research.

Glyphosate vs. Glyphosate-Based Herbicides Exposure: A Review on Their Toxicity

Glyphosate-based herbicide has been the first choice for weed management worldwide since the 1970s, mainly due to its efficacy and reported low toxicity, which contributed to its high acceptance. Many of the recent studies focus solely on the persistence of pesticides in soils, air, water or food products, or even on the degree of exposure of animals, since their potential hazards to human health have raised concerns. Given the unaware exposure of the general population to pesticides, and the absence of a significant number of studies on occupational hazards, new glyphosate-induced toxicity data obtained for both residual and acute doses should be analyzed and systematized. Additionally, recent studies also highlight the persistence and toxicity of both glyphosate metabolites and surfactants present in herbicide formulations. To renew or ban the use of glyphosate, recently published studies must be taken into account, aiming to define new levels of safety for exposure to herbicide, its metabolites, and the toxic excipients of its formulations. This review aims to provide an overview of recent publications (2010–present) on in vitro and in vivo studies aimed at verifying the animal toxicity induced by glyphosate, its metabolite aminomethylphosphonic acid (AMPA) and glyphosate-based formulations, evaluated in various experimental models. Apart from glyphosate-induced toxicity, recent data concerning the role of surfactants in the toxicity of glyphosate-based formulations are discussed.

A Review and Update with Perspective of Evidence that the Herbicide Glyphosate (Roundup) is a Cause of Non-Hodgkin Lymphoma

Glyphosate-based formulations (GBFs), such as Roundup, are the most heavily used herbicides in the world. In 2015, the International Agency for Research on Cancer (IARC) concluded that glyphosate and GBFs are probably carcinogenic to humans (group 2A), mainly for non-Hodgkin lymphoma (NHL). However, this finding has been controversial, and most pesticide regulatory agencies have not followed their lead. The purpose of this review was to examine the scientific literature linking exposure to glyphosate and GBFs to the development of NHL, with emphasis on new findings since publication of the IARC report. The epidemiologic studies provide ample evidence for an association between exposure to GBFs and an increased risk of NHL. Animal studies have shown that glyphosate is carcinogenic in rodents and causes NHL in mice. Mechanistic studies have demonstrated that glyphosate and GBFs are genotoxic to human lymphocytes, the normal cell of origin of NHL, both in vitro and in vivo. Genotoxic and other biological effects have also been shown in various animal and cell models with these agents even at low doses. A novel mechanism underlying the specificity of glyphosate for NHL, that is upregulation of the B-cell genome mutator enzyme activation-induced cytidine deaminase, has recently been demonstrated. These findings were evaluated holistically using the guidelines for evaluation of general causation set forth by Bradford Hill. This evaluation provides coherent and compelling evidence that glyphosate and GBFs are a cause of NHL in humans exposed to these agents. These findings should prompt new reviews by pesticide regulatory agencies around the world.

Study of Sorption Kinetics and Sorption-Desorption Models to Assess the Transport Mechanisms of 2,4-Dichlorophenoxyacetic Acid on Volcanic Soils

The sorption behavior of 2,4-dichlorophenoxyacetic acid (2,4-D) in the abundant agricultural volcanic ash-derived soils (VADS) is not well understood despite being widely used throughout the world, causing effects to the environment and human health. The environmental behavior and risk assessment of groundwater pollution by pesticides can be evaluated through kinetic models. This study evaluated the sorption kinetics and 2,4-D sorption-desorption in ten VADS through batch sorption experiments. Differences in the sorption extent for the fast and slow phases was observed through the IPD model where 2,4-D sorption kinetics was controlled by external mass transfer and intra organic matter diffusion in Andisols (C1 ≠ 0). We confirmed from the spectroscopic analysis that the carboxylate group directly drives the interaction of 2,4-D on Andisol soil. The MLR model showed that IEP, FeDCB, and pH×Silt are important soil descriptors in the 2,4-D sorption in VADS. The Freundlich model accurately represented sorption equilibrium data in all cases (Kf values between 1.1 and 24.1 µg1-1/n mL1/ng-1) with comparatively higher sorption capacity on Andisols, where the highest hysteresis was observed in soils that presented the highest and lowest OC content (H close to 0).

Intranasal glyphosate-based herbicide administration alters the redox balance and the cholinergic system in the mouse brain

Pesticide exposure is associated with cognitive and psychomotor disorders. Glyphosate-based herbicides (GlyBH) are among the most used agrochemicals, and inhalation of GlyBH sprays may arise from frequent aerial pulverizations. Previously, we described that intranasal (IN) administration of GlyBH in mice decreases locomotor activity, increases anxiety, and impairs recognition memory. Then, the aim of the present study was to investigate the mechanisms involved in GlyBH neurotoxicity after IN administration. Adult male CF-1 mice were exposed to GlyBH IN administration (equivalent to 50 mg/kg/day of Gly acid, 3 days a week, during 4 weeks). Total thiol content and the activity of the enzymes catalase, acetylcholinesterase and transaminases were evaluated in different brain areas. In addition, markers of the cholinergic and the nigrostriatal pathways, as well as of astrocytes were evaluated by fluorescence microscopy in coronal brain sections. The brain areas chosen for analysis were those seen to be affected in our previous study. GlyBH IN administration impaired the redox balance of the brain and modified the activities of enzymes involved in cholinergic and glutamatergic pathways. Moreover, GlyBH treatment decreased the number of cholinergic neurons in the medial septum as well as the expression of the α7-acetylcholine receptor in the hippocampus. Also, the number of astrocytes increased in the anterior olfactory nucleus of the exposed mice. Taken together, these disturbances may contribute to the neurobehavioural impairments reported previously by us after IN GlyBH administration in mice.

Use of human neuroblastoma SH-SY5Y cells to evaluate glyphosate-induced effects on oxidative stress, neuronal development and cell death signaling pathways

Glyphosate-containing herbicides are the most used agrochemicals in the world. Their indiscriminate application raises some concerns regarding the possible health and environmental hazards. In this study, we investigated in human neuroblastoma cell line SH-SY5Y if oxidative stress, altered neurodevelopment and cell death pathways are involved in response to glyphosate and its metabolite aminomethylphosphonic acid (AMPA) exposures. MTT and LDH assays were carried out to assess the glyphosate and AMPA cytotoxicity. Lipid peroxides measured as malondialdehyde (MDA), nitric oxide (NO) and reactive oxygen species (ROS) production, and caspase-Glo 3/7 activity were evaluated. The neuroprotective role of melatonin (MEL), Trolox, N-acetylcysteine (NAC) and Sylibin against glyphosate- and AMPA-induced oxidative stress was examined. Glyphosate and AMPA effects on neuronal development related gene transcriptions, and gene expression profiling of cell death pathways by Real-Time PCR array were also investigated. Glyphosate (5 mM) and AMPA (10 mM) induced a significant increase in MDA levels, NO and ROS production and caspase 3/7 activity. Glyphosate exposure induced up-regulation of Wnt3a, Wnt5a, Wnt7a, CAMK2A, CAMK2B and down-regulation of GAP43 and TUBB3 mRNA expression involved in normal neural cell development. In relation to gene expression profiling of cell death pathways, of the 84 genes examined in cells a greater than 2-fold change was observed for APAF1, BAX, BCL2, CASP3, CASP7, CASP9, SYCP2, TNF, TP53, CTSB, NFκB1, PIK3C3, SNCA, SQSTMT, HSPBAP1 and KCNIPI mRNA expression for glyphosate and AMPA exposures. These gene expression data can help to define neurotoxic mechanisms of glyphosate and AMPA. Our results demonstrated that glyphosate and AMPA induced cytotoxic effects on neuronal development, oxidative stress and cell death via apoptotic, autophagy and necrotic pathways and confirmed that glyphosate environmental exposure becomes a concern. This study demonstrates that SH-SY5Y cell line could be considered an in vitro system for pesticide screening.

The Herbicide Glyphosate and Its Apparently Controversial Effect on Human Health: An Updated Clinical Perspective

BACKGROUND

Glyphosate (G) is the most common weed-killer in the world. Every year tons and tons of G are applied on crop fields. G was first introduced in the mid 1970s and since then its usage has gradually increased to reach a peak since 2005. Now G usage is approximately 100 -fold what it was in 1970. Its impact on human health was considered benign at the beginning. But over the years, evidence of a pervasive negative effect of this pesticide on humans has been mounting. Nonetheless, G usage is allowed by government health control agencies (both in the United States and Europe), that rely upon the evidence produced by the G producer. However, the IARC (International Agency for Research on Cancer) in 2015 has stated that G is probable carcinogenic (class 2A), the second highest class in terms of risk.

OBJECTIVE

In this review, we explore the effect of G on human health, focusing in particular on more recent knowledge.

RESULTS

We have attempted to untangle the controversy about the dangers of the product for human beings in view of a very recent development, when the so -called Monsanto Papers, consisting of Emails and memos from Monsanto came to light, revealing a coordinated strategy to manipulate the debate about the safety of glyphosate to the company's advantage.

CONCLUSION

The story of G is a recurrent one (see the tobacco story), that seriously jeopardizes the credibility of the scientific study in the modern era.

Electrochemical method to study the environmental behavior of Glyphosate on volcanic soils: Proposal of adsorption-desorption and transport mechanisms

Glyphosate is used extensively worldwide, but current evidence suggests detrimental effects on the environment, pollinators, and human health. Glyphosate adsorption kinetics and adsorption/desorption were studied through batch sorption experiments in ten typical volcanic ash-derived soils from Andisol and Ultisol orders. Two kinetic models were used to fit the experimental data: i. Models that allowed establishment of principally kinetic parameters and modeling of the adsorption process, and ii. Models described solute transport mechanisms commonly used for remediation purposes. Adsorption kinetic data were best fitted by the pseudo-second-order kinetic model and Two-Site Nonequilibrium model. These models suggest that mechanisms are complex due to rapid surface adsorption in ultisols with mass transfer controlling adsorption kinetics across the boundary layer, as indicated by the highhand lowt_1/2values. High intraparticle diffusion into macropores and micropores was observed for Andisols. The Freundlich model accurately represented adsorption equilibrium data in all cases (R² > 0.9580) with comparatively higher adsorption capacity on Andisols. K_f values (2.50-52.28 μg^1-1/n mL^1/n g^-1) and hysteresis were significant in all studied soils. Taken together, these data suggest that Glyphosate may be adsorbed more on Andisol soils in comparison to Ultisols.

Effect of in ovo glyphosate injection on embryonic development, serum biochemistry, antioxidant status and histopathological changes in newly hatched chicks

This study aimed to investigate the potential toxic effects of pure glyphosate or Roundup^® on hatchability, serum biochemistry and histopathological observation of the liver and kidney of newly hatched chicks. On day six, a total of 225 fertile eggs were obtained from Huafeng breeder hens. The eggs were randomly divided into three treatments: (a) the control group injected with deionized water, (b) the glyphosate group injected 10 mg pure glyphosate/Kg egg mass and (c) the Roundup group injected 10 mg the active ingredient glyphosate in Roundup^® /Kg egg. The results showed a decrease of hatchability rate in chicks treated with Roundup^® (66%). In addition, no significant change was observed in body weights, yolk sac weight and relative weight organs except the liver and kidney were significantly increased with groups treated with glyphosate and Roundup^® compared to the control group. The results showed that serum protein profiles were linearly significantly increased of serum phosphor, uric acid, aspirate aminotransferase, alanine transaminase and alkaline phosphatase in groups treated with Roundup^® , as well as the serum concentrations of triglyceride altered after treatment with glyphosate. Furthermore, oxidative stress was observed in the treated chicks, the glyphosate and Roundup^® induced changes of the content of malondialdehyde in both the liver and kidney, moreover decrease of glutathione peroxidase, total superoxide dismutase and catalase activity in the kidney tissue and serum. Additionally, changes also happened in the histomorphology of the liver and kidney tissue of the treated chicks. It can be concluded that Roundup^® as a probable decrease of hatchability. Exposure to glyphosate alone or Roundup^® caused liver and kidney histopathological alterations, serum parameters imbalances and oxidative stress, also induced a variety of liver and kidney biochemical alterations that might impair normal organ functioning in newly hatched chicks.

Exposure to glyphosate-based herbicides and risk for non-Hodgkin lymphoma: A meta-analysis and supporting evidence

Glyphosate is the most widely used broad-spectrum systemic herbicide in the world. Recent evaluations of the carcinogenic potential of glyphosate-based herbicides (GBHs) by various regional, national, and international agencies have engendered controversy. We investigated whether there was an association between high cumulative exposures to GBHs and increased risk of non-Hodgkin lymphoma (NHL) in humans. We conducted a new meta-analysis that includes the most recent update of the Agricultural Health Study (AHS) cohort published in 2018 along with five case-control studies. Using the highest exposure groups when available in each study, we report the overall meta-relative risk (meta-RR) of NHL in GBH-exposed individuals was increased by 41% (meta-RR = 1.41, 95% confidence interval, CI: 1.13-1.75). For comparison, we also performed a secondary meta-analysis using high-exposure groups with the earlier AHS (2005), and we calculated a meta-RR for NHL of 1.45 (95% CI: 1.11-1.91), which was higher than the meta-RRs reported previously. Multiple sensitivity tests conducted to assess the validity of our findings did not reveal meaningful differences from our primary estimated meta-RR. To contextualize our findings of an increased NHL risk in individuals with high GBH exposure, we reviewed publicly available animal and mechanistic studies related to lymphoma. We documented further support from studies of malignant lymphoma incidence in mice treated with pure glyphosate, as well as potential links between glyphosate / GBH exposure and immunosuppression, endocrine disruption, and genetic alterations that are commonly associated with NHL or lymphomagenesis. Overall, in accordance with findings from experimental animal and mechanistic studies, our current meta-analysis of human epidemiological studies suggests a compelling link between exposures to GBHs and increased risk for NHL.

Viewing evidence of harm accompanying uses of glyphosate-based herbicides under US legal requirements

Some epidemiological experts feel there is sufficient proof that glyphosate use adversely affects human health, and glyphosate has been labeled as probably carcinogenic by the International Agency for Research on Cancer. Federal law in the United States provides two major options under which health concerns about glyphosate use might be addressed. First, registrations of glyphosate-based herbicides (GBHs) need to be cancelled if the costs are greater that its benefits. Since the cancellation of GBH registrations in the United States would lead to higher maize and soybean prices that would adversely affect food security, further analyses are needed. Second, US law requires consideration of the human dietary risk from pesticide residues, and tolerances of allowable amounts of glyphosate residues allowed to remain in or on food items have been established. Social cost curves depicting three options for regulating GBHs show preferred strategies dependent upon the magnitude of adverse effects on human health and food insecurity. Measures to reduce harm to humans can be identified to ameliorate health damages to allow some uses of GBHs to continue, but only if the evidence supports the conclusion that "no harm will result from aggregate exposure to the pesticide chemical residue."

Glyphosate Use and Cancer Incidence in the Agricultural Health Study

Background

Glyphosate is the most commonly used herbicide worldwide, with both residential and agricultural uses. In 2015, the International Agency for Research on Cancer classified glyphosate as "probably carcinogenic to humans," noting strong mechanistic evidence and positive associations for non-Hodgkin lymphoma (NHL) in some epidemiologic studies. A previous evaluation in the Agricultural Health Study (AHS) with follow-up through 2001 found no statistically significant associations with glyphosate use and cancer at any site.

Methods

The AHS is a prospective cohort of licensed pesticide applicators from North Carolina and Iowa. Here, we updated the previous evaluation of glyphosate with cancer incidence from registry linkages through 2012 (North Carolina)/2013 (Iowa). Lifetime days and intensity-weighted lifetime days of glyphosate use were based on self-reported information from enrollment (1993-1997) and follow-up questionnaires (1999-2005). We estimated incidence rate ratios (RRs) and 95% confidence intervals (CIs) using Poisson regression, controlling for potential confounders, including use of other pesticides. All statistical tests were two-sided.

Results

Among 54 251 applicators, 44 932 (82.8%) used glyphosate, including 5779 incident cancer cases (79.3% of all cases). In unlagged analyses, glyphosate was not statistically significantly associated with cancer at any site. However, among applicators in the highest exposure quartile, there was an increased risk of acute myeloid leukemia (AML) compared with never users (RR = 2.44, 95% CI = 0.94 to 6.32, Ptrend = .11), though this association was not statistically significant. Results for AML were similar with a five-year (RRQuartile 4 = 2.32, 95% CI = 0.98 to 5.51, Ptrend = .07) and 20-year exposure lag (RRTertile 3 = 2.04, 95% CI = 1.05 to 3.97, Ptrend = .04).

Conclusions

In this large, prospective cohort study, no association was apparent between glyphosate and any solid tumors or lymphoid malignancies overall, including NHL and its subtypes. There was some evidence of increased risk of AML among the highest exposed group that requires confirmation.

Subchronic exposure to kalach 360 SL-induced endocrine disruption and ovary damage in female rats

Kalach 360 SL (KL), glyphosate (G) surfactant-based herbicides, is a systemic herbicide effective against weeds. It was applied in agriculture in Tunisia and throughout the world, which can represent a risk to non-target organisms. The aim of this study was to investigate the morphological and biochemical aspects of ovary injury after exposure to KL. Female Wistar rats were divided into three groups: group 1 was used as a control; group 2 orally received 0.07 ml of KL, (126 mg of G/kg) and group 3 orally received 0.175 ml of KL (315 mg of G/kg) each day for 60 days. The subchronic exposure of KL induces impaired folliculogenesis, ovary development, decreased oestrogen secretion, promoted oxidative stress and impairments of ovary histological aspects. Histological finding shows necrosis cell, vacuolisation of follicles, dissociated oocytes and granulosa cell, associated with several atretic follicles. We conclude that KL induces endocrine disruption and ovary damage in female rats.

The rise of glyphosate and new opportunities for biosentinel early-warning studies

Glyphosate has become the most commonly used herbicide worldwide and is reputedly environmentally benign, nontoxic, and safe for use near wildlife and humans. However, studies indicate its toxicity is underestimated and its persistence in the environment is greater than once thought. Its actions as a neurotoxin and endocrine disruptor indicate its potential to act in similar ways to persistent organic pollutants such as the organochlorines dichlorodiphenyltrichloroethane (DDT) and dioxin. Exposure to glyphosate and glyphosate-based herbicides for both wildlife and people is likely to be chronic and at sublethal levels, with multiple and ongoing exposure events occurring in urban and agricultural landscapes. Despite this, there has been little research on the impact of glyphosate on wildlife populations, and existing studies appear in the agricultural, toxicology, and water-chemistry literature that may have limited visibility among wildlife biologists. These studies clearly demonstrate a link between chronic exposure and neurotoxicity, endocrine disruption, cell damage, and immune suppression. There is a strong case for the recognition of glyphosate as an emerging organic contaminant and substantial potential exists for collaborative research among ecologists, toxicologists, and chemists to quantify the impact of glyphosate on wildlife and to evaluate the role of biosentinel species in a preemptive move to mitigate downstream impacts on people. There is scope to develop a decision framework to aid the choice of species to biomonitor and analysis methods based on the target contaminant, spatial and temporal extent of contamination, and perceived risk. Birds in particular offer considerable potential in this role because they span agricultural and urban environments, coastal, inland, and wetland ecosystems where glyphosate residues are known to be present.

Effects of low doses of glyphosate on DNA damage, cell proliferation and oxidative stress in the HepG2 cell line

We studied the toxic effects of glyphosate in vitro on HepG2 cells exposed for 4 and 24 h to low glyphosate concentrations likely to be encountered in occupational and residential exposures [the acceptable daily intake (ADI; 0.5 μg/mL), residential exposure level (REL; 2.91 μg/mL) and occupational exposure level (OEL; 3.5 μg/mL)]. The assessments were performed using biomarkers of oxidative stress, CCK-8 colorimetric assay for cell proliferation, alkaline comet assay and cytokinesis-block micronucleus (CBMN) cytome assay. The results obtained indicated effects on cell proliferation, both at 4 and 24 h. The levels of primary DNA damage after 4-h exposure were lower in treated vs. control samples, but were not significantly changed after 24 h. Using the CBMN assay, we found a significantly higher number of MN and nuclear buds at ADI and REL after 4 h and a lower number of MN after 24 h. The obtained results revealed significant oxidative damage. Four-hour exposure resulted in significant decrease at ADI [lipid peroxidation and glutathione peroxidase (GSH-Px)] and OEL [lipid peroxidation and level of total antioxidant capacity (TAC)], and 24-h exposure in significant decrease at OEL (TAC and GSH-Px). No significant effects were observed for the level of reactive oxygen species (ROS) and glutathione (GSH) for both treatment, and for 24 h for lipid peroxidation. Taken together, the elevated levels of cytogenetic damage found by the CBMN assay and the mechanisms of primary DNA damage should be further clarified, considering that the comet assay results indicate possible cross-linking or DNA adduct formation.

Biomonitoring of agricultural workers exposed to pesticide mixtures in Guerrero state, Mexico, with comet assay and micronucleus test

The aim of this study was to evaluate the genotoxic effect of pesticides in exfoliated buccal cells of workers occupationally exposed in Guerrero, Mexico, using the comet assay and the micronucleus test. The study compared 111 agricultural workers in three rural communities (Arcelia 62, Ajuchitlan 13, and Tlapehuala 36), with 60 non-exposed individuals. All the participants were males. The presence of DNA damage was investigated in the exfoliated buccal cells of study participants with the comet assay and the micronucleus (MN) test; comet tail length was evaluated in 100 nuclei and 3000 epithelial cells of each individual, respectively; other nuclear anomalies such as nuclear buds, karyolysis, karyorrhexis, and binucleate cells were also evaluated. Study results revealed that the tail migration of DNA and the frequency of MN increased significantly in the exposed group, which also showed nuclear anomalies associated with cytotoxic or genotoxic effect. No positive correlation was noted between exposure time and tail length and micronuclei frequencies. No significant effect on genetic damage was observed as a result of age, smoking, and alcohol consumption. The MN and comet assay in exfoliated buccal cells are useful and minimally invasive methods for monitoring genetic damage in individuals exposed to pesticides. This study provided valuable data for establishing the possible risk to human health associated with pesticide exposure.

Potential toxic effects of glyphosate and its commercial formulations below regulatory limits

Glyphosate-based herbicides (GlyBH), including Roundup, are the most widely used pesticides worldwide. Their uses have increased exponentially since their introduction on the market. Residue levels in food or water, as well as human exposures, are escalating. We have reviewed the toxic effects of GlyBH measured below regulatory limits by evaluating the published literature and regulatory reports. We reveal a coherent body of evidence indicating that GlyBH could be toxic below the regulatory lowest observed adverse effect level for chronic toxic effects. It includes teratogenic, tumorigenic and hepatorenal effects. They could be explained by endocrine disruption and oxidative stress, causing metabolic alterations, depending on dose and exposure time. Some effects were detected in the range of the recommended acceptable daily intake. Toxic effects of commercial formulations can also be explained by GlyBH adjuvants, which have their own toxicity, but also enhance glyphosate toxicity. These challenge the assumption of safety of GlyBH at the levels at which they contaminate food and the environment, albeit these levels may fall below regulatory thresholds. Neurodevelopmental, reproductive, and transgenerational effects of GlyBH must be revisited, since a growing body of knowledge suggests the predominance of endocrine disrupting mechanisms caused by environmentally relevant levels of exposure.

Review of genotoxicity biomonitoring studies of glyphosate-based formulations

Abstract Human and environmental genotoxicity biomonitoring studies involving exposure to glyphosate-based formulations (GBFs) were reviewed to complement an earlier review of experimental genotoxicity studies of glyphosate and GBFs. The environmental and most of the human biomonitoring studies were not informative because there was either a very low frequency of GBF exposure or exposure to a large number of pesticides without analysis of specific pesticide effects. One pesticide sprayer biomonitoring study indicated there was not a statistically significant relationship between frequency of GBF exposure reported for the last spraying season and oxidative DNA damage. There were three studies of human populations in regions of GBF aerial spraying. One study found increases for the cytokinesis-block micronucleus endpoint but these increases did not show statistically significant associations with self-reported spray exposure and were not consistent with application rates. A second study found increases for the blood cell comet endpoint at high exposures causing toxicity. However, a follow-up to this study 2 years after spraying did not indicate chromosomal effects. The results of the biomonitoring studies do not contradict an earlier conclusion derived from experimental genotoxicity studies that typical GBFs do not appear to present significant genotoxic risk under normal conditions of human or environmental exposures.

Glyphosate-rich air samples induce IL-33, TSLP and generate IL-13 dependent airway inflammation

Several low weight molecules have often been implicated in the induction of occupational asthma. Glyphosate, a small molecule herbicide, is widely used in the world. There is a controversy regarding a role of glyphosate in developing asthma and rhinitis among farmers, the mechanism of which is unexplored. The aim of this study was to explore the mechanisms of glyphosate induced pulmonary pathology by utilizing murine models and real environmental samples. C57BL/6, TLR4-/-, and IL-13-/- mice inhaled extracts of glyphosate-rich air samples collected on farms during spraying of herbicides or inhaled different doses of glyphosate and ovalbumin. The cellular response, humoral response, and lung function of exposed mice were evaluated. Exposure to glyphosate-rich air samples as well as glyphosate alone to the lungs increased: eosinophil and neutrophil counts, mast cell degranulation, and production of IL-33, TSLP, IL-13, and IL-5. In contrast, in vivo systemic IL-4 production was not increased. Co-administration of ovalbumin with glyphosate did not substantially change the inflammatory immune response. However, IL-13-deficiency resulted in diminished inflammatory response but did not have a significant effect on airway resistance upon methacholine challenge after 7 or 21 days of glyphosate exposure. Glyphosate-rich farm air samples as well as glyphosate alone were found to induce pulmonary IL-13-dependent inflammation and promote Th2 type cytokines, but not IL-4 for glyphosate alone. This study, for the first time, provides evidence for the mechanism of glyphosate-induced occupational lung disease.

Genotoxicity of mixtures of glyphosate and atrazine and their environmental transformation products before and after photoactivation

The photo-inducible cytogenetic toxicity of glyphosate, atrazine, aminomethyl phosphoric acid (AMPA), desethyl-atrazine (DEA), and their various mixtures was assessed by the in vitro micronucleus assay on CHO-K1 cells. Results demonstrated that the cytogenetic potentials of pesticides greatly depended on their physico-chemical environment. The mixture made with the four pesticides exhibited the most potent cytogenetic toxicity, which was 20-fold higher than those of the most active compound AMPA, and 100-fold increased after light-irradiation. Intracellular ROS assessment suggested the involvement of oxidative stress in the genotoxic impact of pesticides and pesticide mixtures. This study established that enhanced cytogenetic activities could be observed in pesticide mixtures containing glyphosate, atrazine, and their degradation products AMPA and DEA. It highlighted the importance of cocktail effects in environmental matrices, and pointed out the limits of usual testing strategies based on individual molecules, to efficiently estimate environmental risks.

Glyphosate commercial formulation causes cytotoxicity, oxidative effects, and apoptosis on human cells: differences with its active ingredient

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.

Mutagenicity and genotoxicity in gill erythrocyte cells of Poecilia reticulata exposed to a glyphosate formulation

Poecilia reticulata were exposed to herbicide Roundup Transorb(®) for micronucleus test, nuclear abnormalities and comet assay. The exposure-concentrations were based on CL50-96 h following 0, 1.41, 2.83, 4.24 and 5.65 μL L(-1) for 24 h. Micronucleus and comets were significantly increased in the gill erythrocyte cells after herbicide exposure compared with the non-exposed group. Results showed a gradual increase in the number of damaged cells, indicating a concentration-dependent effect and that this herbicide was mutagenic and genotoxic to P. reticulata and this effect could be attributed to a combination of compounds contained in the formulation with the active ingredient glyphosate.

Evaluation of the genotoxic and cytotoxic effects of glyphosate-based herbicides in the ten spotted live-bearer fish Cnesterodon decemmaculatus (Jenyns, 1842)

Mortality, genotoxicity, and cytotoxicity of the 48% glyphosate-based formulations Panzer and Credit(®) were evaluated on Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae) under laboratory conditions. Induction of micronuclei (MN) and alterations in the erythrocytes:erythroblasts ratio were employed as end points for genotoxicity and cytotoxicity, respectively. For Panzer(®), mean values of 16.70 and 15.68 mg/L were determined for LC(50) at 24 and 96 h, respectively, and these concentrations reached mean values of 98.50 and 91.73 mg/L for Credit(®). LC(50) values decreased as a negative linear function of Panzer(®) exposure time within the 0-96 h period, but not for Credit(®). LC(50) values indicated that the fish were more sensitive to Panzer(®) than to Credit(®). Both 3.9 and 7.8 mg/L of Panzer(®) increased MN frequency at 48 and 96 h of treatment. When fish were exposed to Credit(®), an increased frequency of MN over control values was found after 96 h for all concentrations assayed, but not after 48 h. No cellular cytotoxicity was found after Panzer(®) and Credit(®) treatment, regardless of both the concentration and the sampling time. Furthermore, our results demonstrated that Panzer(®) and Credit(®) should be considered as glyphosate-based commercial formulations with genotoxic but not cytotoxic effect properties.

Comparison of the in vivo and in vitro genotoxicity of glyphosate isopropylamine salt in three different organisms

There is considerable controversy with regard to the genotoxicity of glyphosate, with some reports stating that this compound is non-toxic for fish, birds and mammals. In this work, we used the comet assay to examine the genotoxicity of glyphosate isopropylamine (0.7, 7, 70 and 700 μM) in human lymphocytes, erythrocytes of Oreochromis niloticus and staminal nuclei of Tradescantia (4430) in vitro and in vivo. Cells, nuclei and fish that had and had not been exposed to 5 mM N-nitrosodiethylamine (NDEA) were used as positive and negative controls, respectively. Significant (p < 0.01) genetic damage was observed in vivo and in vitro in all cell types and organisms tested. Human lymphocytes and Tradescantia hairs showed lower genetic damage in vivo compared to in vitro, possibly because of efficient metabolization of the herbicide. In O. niloticus erythrocytes, significant (p < 0.001) genotoxicity was observed at ≥ 7 μM, whereas in vitro, glyphosphate was genotoxic in human lymphocytes and Tradescantia hairs at ≥ 0.7 μM. These results indicate that glyphosate is genotoxic in the cells and organisms studied at concentrations of 0.7-7 μM.

Cytotoxic and DNA-damaging properties of glyphosate and Roundup in human-derived buccal epithelial cells

Glyphosate (G) is the largest selling herbicide worldwide; the most common formulations (Roundup, R) contain polyoxyethyleneamine as main surfactant. Recent findings indicate that G exposure may cause DNA damage and cancer in humans. Aim of this investigation was to study the cytotoxic and genotoxic properties of G and R (UltraMax) in a buccal epithelial cell line (TR146), as workers are exposed via inhalation to the herbicide. R induced acute cytotoxic effects at concentrations > 40 mg/l after 20 min, which were due to membrane damage and impairment of mitochondrial functions. With G, increased release of extracellular lactate dehydrogenase indicative for membrane damage was observed at doses > 80 mg/l. Both G and R induced DNA migration in single-cell gel electrophoresis assays at doses > 20 mg/l. Furthermore, an increase of nuclear aberrations that reflect DNA damage was observed. The frequencies of micronuclei and nuclear buds were elevated after 20-min exposure to 10-20 mg/l, while nucleoplasmatic bridges were only enhanced by R at the highest dose (20 mg/l). R was under all conditions more active than its active principle (G). Comparisons with results of earlier studies with lymphocytes and cells from internal organs indicate that epithelial cells are more susceptible to the cytotoxic and DNA-damaging properties of the herbicide and its formulation. Since we found genotoxic effects after short exposure to concentrations that correspond to a 450-fold dilution of spraying used in agriculture, our findings indicate that inhalation may cause DNA damage in exposed individuals.

Genotoxicity studies performed in the ecuadorian population

Genotoxicity studies in Ecuador have been carried out during the past two decades. The focuses of the research were mainly the area of environmental issues, where the populations have been accidentally exposed to contaminants and the area of occupational exposure of individuals at the workplace. This paper includes studies carried out in the population of the Amazon region, a zone known for its rich biodiversity as well as for the ecological damage caused by oil spills and chemical sprayings whose consequences continue to be controversial. Additionally, we show the results of studies comprised of individuals occupationally exposed to toxic agents in two very different settings: flower plantation workers exposed to pesticide mixtures and X-ray exposure of hospital workers. The results from these studies confirm that genotoxicity studies can help evaluate current conditions and prevent further damage in the populations exposed to contaminants. As such, they are evidence of the need for biomonitoring employers at risk, stricter law enforcement regarding the use of pesticides, and increasingly conscientious oil extraction activities.

Baseline determination in social, health, and genetic areas in communities affected by glyphosate aerial spraying on the northeastern Ecuadorian border

The northeastern Ecuadorian border has undergone aerial spraying with an herbicide mix that contains surfactants and adjuvants, executed by the Colombian Government. The purpose of this study was to diagnose social, health, and genetic aspects of the people affected by glyphosate. For this objective to be achieved, 144 people were interviewed, and 521 medical diagnoses and 182 peripheral blood samples were obtained. Genotyping of GSTP1 Ile105Val, GPX-1 Pro198Leu, and XRCC1 Arg399Gln polymorphisms were analyzed, using PCR-RFLP technique. The assessment of chromosomal aberrations was performed, obtaining 182 karyotypes. Malnutrition in children was 3%. Of the total population, 7.7% had children with malformations, and the percentage of abortions was 12.7%. Concerning genotyping, individuals with GSTP1 Val/Val obtained an odds ratio of 4.88 (p < 0.001), and Ile/Val individuals, together with Val/Val individuals, had an odds ratio of 2.6 (p < 0.05). In addition, GPX-1 Leu/Leu individuals presented an odds ratio (OR) of 8.5 (p < 0.05). Regarding karyotyping, the 182 individuals had normal karyotypes. In conclusion, the study population did not present significant chromosomal and DNA alterations. The most important social impact was fear. We recommend future prospective studies to assess the communities.

Genotoxicity of glyphosate assessed by the comet assay and cytogenetic tests

It was evaluated the genotoxicity of glyphosate which up to now has heterogeneous results. The comet assay was performed in Hep-2 cells. The level of DNA damage in the control group (5.42±1.83 arbitrary units) for tail moment (TM) measurements has shown a significant increase (p<0.01) with glyphosate at a range concentration from 3.00 to 7.50mM. In the chromosome aberrations (CA) test in human lymphocytes the herbicide (0.20-6.00mM) showed no significant effects in comparison with the control group. In vivo, the micronucleus test (MNT) was evaluated in mice at three doses rendering statistical significant increases at 400mg/kg (13.0±3.08 micronucleated erythrocytes/1000 cells, p<0.01). In the present study glyphosate was genotoxic in the comet assay in Hep-2 cells and in the MNT test at 400mg/kg in mice. Thiobarbituric acid reactive substances (TBARs) levels, superoxide dismutase (SOD) and catalase (CAT) activities were quantified in their organs. The results showed an increase in these enzyme activities.

Biomonitoring of genotoxic risk in agricultural workers from five colombian regions: association to occupational exposure to glyphosate

In order to assess possible human effects associated with glyphosate formulations used in the Colombian aerial spray program for control of illicit crops, a cytogenetic biomonitoring study was carried out in subjects from five Colombian regions, characterized by different exposure to glyphosate and other pesticides. Women of reproductive age (137 persons 15-49 yr old) and their spouses (137 persons) were interviewed to obtain data on current health status, history, lifestyle, including past and current occupational exposure to pesticides, and factors including those known to be associated with increased frequency of micronuclei (MN). In regions where glyphosate was being sprayed, blood samples were taken prior to spraying (indicative of baseline exposure), 5 d after spraying, and 4 mo after spraying. Lymphocytes were cultured and a cytokinesis-block micronucleus cytome assay was applied to evaluate chromosomal damage and cytotoxicity. Compared with Santa Marta, where organic coffee is grown without pesticides, the baseline frequency of binucleated cells with micronuclei (BNMN) was significantly greater in subjects from the other four regions. The highest frequency of BNMN was in Boyaca, where no aerial eradication spraying of glyphosate was conducted, and in Valle del Cauca, where glyphosate was used for maturation of sugar cane. Region, gender, and older age (> or =35 yr) were the only variables associated with the frequency of BNMN measured before spraying. A significant increase in frequency of BNMN between first and second sampling was observed in Narino, Putumayo, and Valle immediately (<5 d) after spraying. In the post-spray sample, those who reported direct contact with the eradication spray showed a higher quantitative frequency of BNMN compared to those without glyphosate exposure. The increase in frequency of BNMN observed immediately after the glyphosate spraying was not consistent with the rates of application used in the regions and there was no association between self-reported direct contact with eradication sprays and frequency of BNMN. Four months after spraying, a statistically significant decrease in the mean frequency of BNMN compared with the second sampling was observed in Narino, but not in Putumayo and Valle del Cauca. Overall, data suggest that genotoxic damage associated with glyphosate spraying for control of illicit crops as evidenced by MN test is small and appears to be transient. Evidence indicates that the genotoxic risk potentially associated with exposure to glyphosate in the areas where the herbicide is applied for coca and poppy eradication is low.