Bai and Ogbourne, 2016
Bai, S. H., & Ogbourne, S. M., “Glyphosate: environmental contamination, toxicity and potential risks to human health via food contamination,” Environmental Science and Pollution Research, 2016, 23(19), 18988-19001. DOI: 10.1007/s11356-016-7425-3.
ABSTRACT:
Glyphosate has been the most widely used herbicide during the past three decades. The US Environmental Protection Agency (EPA) classifies glyphosate as ‘practically non-toxic and not an irritant’ under the acute toxicity classification system. This classification is based primarily on toxicity data and due to its unique mode of action via a biochemical pathway that only exists in a small number of organisms that utilise the shikimic acid pathway to produce amino acids, most of which are green plants. This classification is supported by the majority of scientific literature on the toxic effects of glyphosate. However, in 2005, the Food and Agriculture Organisation (FAO) reported that glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), are of potential toxicological concern, mainly as a result of accumulation of residues in the food chain. The FAO further states that the dietary risk of glyphosate and AMPA is unlikely if the maximum daily intake of 1 mg kg(-1) body weight (bw) is not exceeded. Research has now established that glyphosate can persist in the environment, and therefore, assessments of the health risks associated with glyphosate are more complicated than suggested by acute toxicity data that relate primarily to accidental high-rate exposure. We have used recent literature to assess the possible risks associated with the presence of glyphosate residues in food and the environment. FULL TEXT
Slaby et al., 2019
Slaby, S., Titran, P., Marchand, G., Hanotel, J., Lescuyer, A., Lepretre, A., Bodart, J. F., Marin, M., & Lemiere, S., “Effects of glyphosate and a commercial formulation Roundup(R) exposures on maturation of Xenopus laevis oocytes,” Environmental Science and Pollution Research International, 2019. DOI: 10.1007/s11356-019-04596-2.
ABSTRACT:
Pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. Even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. While their populations are highly threatened with extinction. The aim of this work is to characterize the effects of glyphosate and its commercial formulation Roundup(R) GT Max on the Xenopus laevis oocyte maturation which is an essential preparation for the laying and the fertilization. Glyphosate is an extensively used herbicide, not only known for its effectiveness but also for its indirect impacts on non-target organisms. Our results showed that exposures to both forms of glyphosate delayed this hormone-dependent process and were responsible for spontaneous maturation. Severe and particular morphogenesis abnormalities of the meiotic spindle were also observed. The MAPK pathway and the MPF did not seem to be affected by exposures. The xenopus oocyte is particularly affected by the exposures and appears as a relevant model for assessing the effects of environmental contamination. FULL TEXT
Pahwa et al., 2012
Pahwa, M., Harris, S. A., Hohenadel, K., McLaughlin, J. R., Spinelli, J. J., Pahwa, P., Dosman, J. A., & Blair, A., “Pesticide use, immunologic conditions, and risk of non-Hodgkin lymphoma in Canadian men in six provinces,” International Journal of Cancer, 2012, 131(11), 2650-2659. DOI: 10.1002/ijc.27522.
ABSTRACT:
Pesticide exposures and immune suppression have been independently associated with the risk of non-Hodgkin lymphoma (NHL), but their joint effect has not been well explored. Data from a case-control study of men from six Canadian provinces were used to evaluate the potential effect modification of asthma, allergies, or asthma and allergies and hay fever combined on NHL risk from use of: (i) any pesticide; (ii) any organochlorine insecticide; (iii) any organophosphate insecticide; (iv) any phenoxy herbicide; (v) selected individual pesticides [1,1′-(2,2,2-trichloroethylidene)bis[4-chlorobenzene]; 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT), malathion, (4-chloro-2-methylphenoxy)acetic acid (MCPA), mecoprop, and (2,4-dichlorophenoxy)acetic acid (2,4-D); and (vi) from the number of potentially carcinogenic pesticides. Incident NHL cases (n = 513) diagnosed between 1991 and 1994 were recruited from provincial cancer registries and hospitalization records and compared to 1,506 controls. A stratified analysis was conducted to calculate odds ratios (ORs) adjusted for age, province, proxy respondent, and diesel oil exposure. Subjects with asthma, allergies, or hay fever had non-significantly elevated risks of NHL associated with use of MCPA (OR = 2.67, 95% confidence interval [CI]: 0.90-7.93) compared to subjects without any of these conditions (OR = 0.81, 95% CI: 0.39-1.70). Conversely, those with asthma, allergies, or hay fever who reported use of malathion had lower risks of NHL (OR = 1.25, 95% CI: 0.69-2.26) versus subjects with none of these conditions (OR = 2.44, 95% CI: 1.65-3.61). Similar effects were observed for asthma and allergies evaluated individually. Although there were some leads regarding effect modification by these immunologic conditions on the association between pesticide use and NHL, small numbers, measurement error and possible recall bias limit interpretation of these results. FULL TEXT
von Ehrenstein et al., 2019
von Ehrenstein, O. S., Ling, C., Cui, X., Cockburn, M., Park, A. S., Yu, F., Wu, J., & Ritz, B., “Prenatal and infant exposure to ambient pesticides and autism spectrum disorder in children: population based case-control study,” BMJ, 2019, 364, l962. DOI: 10.1136/bmj.l962.
ABSTRACT:
OBJECTIVE: To examine associations between early developmental exposure to ambient pesticides and autism spectrum disorder.
DESIGN: Population based case-control study.
SETTING: California’s main agricultural region, Central Valley, using 1998-2010 birth data from the Office of Vital Statistics.
POPULATION: 2961 individuals with a diagnosis of autism spectrum disorder based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, revised (up to 31 December 2013), including 445 with intellectual disability comorbidity, were identified through records maintained at the California Department of Developmental Services and linked to their birth records. Controls derived from birth records were matched to cases 10:1 by sex and birth year.
EXPOSURE: Data from California state mandated Pesticide Use Reporting were integrated into a geographic information system tool to estimate prenatal and infant exposures to pesticides (measured as pounds of pesticides applied per acre/month within 2000 m from the maternal residence). 11 high use pesticides were selected for examination a priori according to previous evidence of neurodevelopmental toxicity in vivo or in vitro (exposure defined as ever v never for each pesticide during specific developmental periods).
MAIN OUTCOME MEASURE: Odds ratios and 95% confidence intervals using multivariable logistic regression were used to assess associations between pesticide exposure and autism spectrum disorder (with or without intellectual disabilities) in offspring, adjusting for confounders.
RESULTS: Risk of autism spectrum disorder was associated with prenatal exposure to glyphosate (odds ratio 1.16, 95% confidence interval 1.06 to 1.27), chlorpyrifos (1.13, 1.05 to 1.23), diazinon (1.11, 1.01 to 1.21), malathion (1.11, 1.01 to 1.22), avermectin (1.12, 1.04 to 1.22), and permethrin (1.10, 1.01 to 1.20). For autism spectrum disorder with intellectual disability, estimated odds ratios were higher (by about 30%) for prenatal exposure to glyphosate (1.33, 1.05 to 1.69), chlorpyrifos (1.27, 1.04 to 1.56), diazinon (1.41, 1.15 to 1.73), permethrin (1.46, 1.20 to 1.78), methyl bromide (1.33, 1.07 to 1.64), and myclobutanil (1.32, 1.09 to 1.60); exposure in the first year of life increased the odds for the disorder with comorbid intellectual disability by up to 50% for some pesticide substances.
CONCLUSION: Findings suggest that an offspring’s risk of autism spectrum disorder increases following prenatal exposure to ambient pesticides within 2000 m of their mother’s residence during pregnancy, compared with offspring of women from the same agricultural region without such exposure. Infant exposure could further increase risks for autism spectrum disorder with comorbid intellectual disability. FULL TEXT
Zhang et al., 2019a
Zhang, Luoping, Rana, Iemaan, Shaffer, Rachel M., Taioli, Emanuela, & Sheppard, Lianne, “Exposure to Glyphosate-Based Herbicides and Risk for Non-Hodgkin Lymphoma: A Meta-Analysis and Supporting Evidence,” Mutation Research/Reviews in Mutation Research, In Press, 2019. DOI: 10.1016/j.mrrev.2019.02.001.
ABSTRACT:
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 included 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% CI, confidence interval: 1.13–1.75). For comparison, we also performed a secondary meta-analysis using high-exposure groups with the earlier AHS (2005), and we determined 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 available animal and mechanistic studies, which provided supporting evidence for the carcinogenic potential of GBH. We documented further support from studies of malignant lymphoma incidence in mice treated with pure glyphosate, as well as potential links between GBH exposure and immunosuppression, endocrine disruption, and genetic alterations that are commonly associated with NHL. Overall, in accordance with evidence 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. FULL TEXT
Wozniak et al., 2018
Wozniak, E., Sicinska, P., Michalowicz, J., Wozniak, K., Reszka, E., Huras, B., Zakrzewski, J., & Bukowska, B., “The mechanism of DNA damage induced by Roundup 360 PLUS, glyphosate and AMPA in human peripheral blood mononuclear cells – genotoxic risk assessement,” Food and Chemical Toxicology, 2018, 120, 510-522. DOI: 10.1016/j.fct.2018.07.035.
ABSTRACT:
Glyphosate is the most heavily applied among pesticides in the world, and thus human exposure to this substance continues to increase. WHO changed classification of glyphosate to probably cancerogenic to humans, thus there is urgent need to assess in detail genotoxic mechanism of its action. We have assessed the effect of glyphosate, its formulation (Roundup 360 PLUS) and its main metabolite (aminomethylphosphonic acid, AMPA) in the concentration range from 1 to 1000muM on DNA damage in human peripheral blood mononuclear cells (PBMCs). The cells were incubated for 24h. The compounds studied and formulation induced DNA single and double strand-breaks and caused purines and pyrimidines oxidation. None of compounds examined was capable of creating adducts with DNA, while those substances increased ROS (including (*)OH) level in PBMCs. Roundup 360 PLUS caused damage to DNA even at 5muM, while glyphosate and particularly AMPA induced DNA lesions from the concentration of 250muM and 500muM, respectively. DNA damage induced by glyphosate and its derivatives increased in order: AMPA, glyphosate, Roundup 360 PLUS. We may conclude that observed changes were not associated with direct interaction of xenobiotics studied with DNA, but the most probably they occurred through ROS-mediated effects. FULL TEXT
Ward, 2018
Ward, E. M., “Glyphosate Use and Cancer Incidence in the Agricultural Health Study: An Epidemiologic Perspective,” Journal of the National Cancer Institute, 2018, 110(5), 446-447. DOI: 10.1093/jnci/djx247.
ABSTRACT:
Not Available. FULL TEXT
Varayoud et al., 2017
Varayoud, J., Durando, M., Ramos, J. G., Milesi, M. M., Ingaramo, P. I., Munoz-de-Toro, M., & Luque, E. H., “Effects of a glyphosate-based herbicide on the uterus of adult ovariectomized rats,” Environmental Toxicology, 2017, 32(4), 1191-1201. DOI: 10.1002/tox.22316.
ABSTRACT:
Glyphosate is the active ingredient of several herbicide formulations. Different reports suggest that glyphosate-based herbicides (GBHs) may act as endocrine disruptors. We evaluated the potential estrogenic effects of a GBH formulation using the uterotrophic assay. Adult ovariectomized rats were sc injected for 3 consecutive days with: saline solution (vehicle control), 2.10(-5) g E2 /kg/day (uterotrophic dose; UE2 ), 2.10(-7) g E2 /kg/day (nonuterotrophic dose; NUE2), or 0.5, 5, or 50 mg GBH/kg/day of the. Twenty-four hours after the last injection, the uterus was removed and weighed and processed for histopathology and mRNA extraction. Epithelial cell proliferation and height and expression of estrogen-responsive genes were evaluated (estrogen receptors, ERalpha and ERbeta; progesterone receptor, PR; complement 3, C3). Uterine weight and epithelial proliferation were not affected by GBH. However, the luminal epithelial cell height increased at GBH0.5. ERalpha mRNA was downregulated by all GBH doses and E2 groups, whereas PR and C3 mRNA were diminished by GBH0.5. GBH5-, GBH50-, and UE2 -treated rats showed downregulated ERalpha protein expression in luminal epithelial cells, while the receptor was upregulated in the stroma. GBH upregulated ERbeta (GBH0.5-50) and PR (GBH5) expressions in glandular epithelial cells, similar effect to that of NUE2 group. These results indicate that, although the uterine weight was not affected, GBH modulates the expression of estrogen-sensitive genes. (c) 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1191-1201, 2017.
Valle et al., 2018
Valle, A. L., Mello, F. C. C., Alves-Balvedi, R. P., Rodrigues, L. P., & Goulart, L. R., “Glyphosate detection: methods, needs and challenges,” Environmental Chemistry Letters, 2018. DOI: 10.1007/s10311-018-0789-5.
ABSTRACT:
Glyphosate is considered toxicologically harmful and presents potential association with human carcinogenesis and other chronic diseases, including mental and reproductive behaviors. The challenges to analyse and demonstrate its toxicity are likely due to its metal-chelating properties, the interference of organic compounds in the environment, and similarity with its by-products. Whereas there is a link with serious health and environmental problems, there is an absence of public health policies, which is probably due to the difficulties in detecting glyphosate in the environment, further complicated by the undetectable hazard in occupational safety and health. The historical lenient use of glyphosate in transgenic-resistant crops, corroborated by the fact that it is not easily detected, creates the “Glyphosate paradox”, by which it is the most widely used herbicide and one of the most hardly determined. In this review, we revisited all available technologies for detection and quantification of glyphosate, including their drawbacks and advantages, and we further discuss the needs and challenges. Briefly, most of the technologies require high-end equipments and resources in low throughput, and none of them are adequate for real-time field tests, which may explain the lack of studies on occupational health associated with the chemical hazard. The real-time detection is an urgent and highly demanded need to improve public policies. FULL TEXT
Townsend et al., 2017
Townsend, M., Peck, C., Meng, W., Heaton, M., Robison, R., & O’Neill, K., “Evaluation of various glyphosate concentrations on DNA damage in human Raji cells and its impact on cytotoxicity,” Regulatory Toxicology and Pharmacology, 2017, 85, 79-85. DOI: 10.1016/j.yrtph.2017.02.002.
ABSTRACT:
Glyphosate is a highly used active compound in agriculturally based pesticides. The literature regarding the toxicity of glyphosate to human cells has been highly inconsistent. We studied the resulting DNA damage and cytotoxicity of various glyphosate concentrations on human cells to evaluate DNA damaging potential. Utilizing human Raji cells, DNA damage was quantified using the comet assay, while cytotoxicity was further analyzed using MTT viability assays. Several glyphosate concentrations were assessed, ranging from 15 mM to 0.1 muM. We found that glyphosate treatment is lethal to Raji cells at concentrations above 10 mM, yet has no cytotoxic effects at concentrations at or below 100 muM. Treatment concentrations of 1 mM and 5 mM induce statistically significant DNA damage to Raji cells following 30-60 min of treatment, however, cells show a slow recovery from initial damage and cell viability is unaffected after 2 h. At these same concentrations, cells treated with additional compound did not recover and maintained high levels of DNA damage. While the cytotoxicity of glyphosate appears to be minimal for physiologically relevant concentrations, the compound has a definitive cytotoxic nature in human cells at high concentrations. Our data also suggests a mammalian metabolic pathway for the degradation of glyphosate may be present. FULL TEXT