Glyphosate - HH-RA.org

Bibliography Tag: glyphosate

Benbrook, 2018

Benbrook, Charles, “Why Regulators Lost Track and Control of Pesticide Risks: Lessons From the Case of Glyphosate-Based Herbicides and Genetically Engineered-Crop Technology,” Current Environmental Health Reports, 5:3, 387-395, 2018, DOI:10.1007/s40572-018-0207-y.

ABSTRACT:

PURPOSE OF REVIEW: The approval of genetically engineered (GE) crops in the late 1990s triggered dramatic changes in corn, soybean, and cotton pest management systems, as well as complex, novel regulatory challenges. Lessons learned are reviewed and solutions described.

RECENT FINDINGS: Government-imposed resistance management provisions can work and adapt to changing circumstances, but within the private sector, pressures to gain and hold market share have thus far trumped the widely recognized need for resistance management. Risks arising from the use of formulated pesticides often exceed by a wide margin those in regulatory risk assessments based on data derived from studies on nearly 100% pure active ingredients.

SUMMARY: Innovative policy changes are needed in four problem areas: excessive faith in the accuracy of pre-market risk assessments and regulatory thresholds; post-approval monitoring of actual impacts; risk arising from formulated pesticides, rather than just pure active ingredient; challenges inherent in assessing and mitigating the combined impacts of all GE traits and associated pesticides on agroecosystems, as opposed to each trait or pesticide alone; and, tools to deal with failing pest management systems. FULL TEXT

Bailey et al., 2018

Bailey, D. C., Todt, C. E., Burchfield, S. L., Pressley, A. S., Denney, R. D., Snapp, I. B., Negga, R., Traynor, W. L., & Fitsanakis, V. A., “Chronic exposure to a glyphosate-containing pesticide leads to mitochondrial dysfunction and increased reactive oxygen species production in Caenorhabditis elegans,” Environmental Toxicology and Pharmacology, 2048, 57, 46-52. DOI: 10.1016/j.etap.2017.11.005.

ABSTRACT:

Glyphosate-containing herbicides are among the most widely-used in the world. Although glyphosate itself is relatively non-toxic, growing evidence suggests that commercial herbicide formulations may lead to increased oxidative stress and mitochondrial inhibition. In order to assess these mechanisms in vivo, we chronically (24h) exposed Caenorhabditis elegans to various concentrations of the glyphosate-containing herbicide TouchDown (TD). Following TD exposure, we evaluated the function of specific mitochondrial electron transport chain complexes. Initial oxygen consumption studies demonstrated inhibition in mid- and high-TD concentration treatment groups compared to controls. Results from tetramethylrhodamine ethyl ester and ATP assays indicated reductions in the proton gradient and ATP levels, respectively. Additional studies were designed to determine whether TD exposure resulted in increased reactive oxygen species (ROS) production. Data from hydrogen peroxide, but not superoxide or hydroxyl radical, assays showed statistically significant increases in this specific ROS. Taken together, these data indicate that exposure of Caenorhabditis elegans to TD leads to mitochondrial inhibition and hydrogen peroxide production. FULL TEXT

Anifandis et al., 2017

Anifandis, G., Amiridis, G., Dafopoulos, K., Daponte, A., Dovolou, E., Gavriil, E., Gorgogietas, V., Kachpani, E., Mamuris, Z., Messini, C. I., Vassiou, K., & Psarra, A. G., “The In Vitro Impact of the Herbicide Roundup on Human Sperm Motility and Sperm Mitochondria,” Toxics, 2017, 6:1, DOI:10.3390/toxics6010002.

ABSTRACT:

Toxicants, such as herbicides, have been hypothesized to affect sperm parameters. The most common method of exposure to herbicides is through spraying or diet. The aim of the present study was to investigate the effect of direct exposure of sperm to 1 mg/L of the herbicide Roundup on sperm motility and mitochondrial integrity. Sperm samples from 66 healthy men who were seeking semen analysis were investigated after written informed consent was taken. Semen analysis was performed according to the World Health Organization guidelines (WHO, 2010). Mitochondrial integrity was assessed through mitochondrial staining using a mitochondria-specific dye, which is exclusively incorporated into functionally active mitochondria. A quantity of 1 mg/L of Roundup was found to exert a deleterious effect on sperm’s progressive motility, after 1 h of incubation (mean difference between treated and control samples = 11.2%) in comparison with the effect after three hours of incubation (mean difference = 6.33%, p < 0.05), while the relative incorporation of the mitochondrial dye in mitochondria of the mid-piece region of Roundup-treated spermatozoa was significantly reduced compared to relative controls at the first hour of incubation, indicating mitochondrial dysfunction by Roundup. Our results indicate that the direct exposure of semen samples to the active constituent of the herbicide Roundup at the relatively low concentration of 1 mg/L has adverse effects on sperm motility, and this may be related to the observed reduction in mitochondrial staining. FULL TEXT

Alarcon et al., 2019

Alarcon, R., Ingaramo, P. I., Rivera, O. E., Dioguardi, G. H., Repetti, M. R., Demonte, L. D., Milesi, M. M., Varayoud, J., Munoz-de-Toro, M., & Luque, E. H., “Neonatal exposure to a glyphosate-based herbicide alters the histofunctional differentiation of the ovaries and uterus in lambs,” Molecular and Cellular Endocrinology, 2019, 482, 45-56. DOI: 10.1016/j.mce.2018.12.007.

ABSTRACT:

The aim of the present study was to compare the effect of oral and subcutaneous exposure to a glyphosate-based herbicide (GBH) on the female reproductive system, specifically in the ovaries and uterus of prepubertal lambs. To this end, ewe lambs were exposed to a s.c. (n: 5) or an oral (n: 5) environmentally relevant dose of GBH (2mg/kg/day) or to vehicle (controls, n: 12), from postnatal day (PND) 1 to PND14. Serum glyphosate and aminomethylphosphonic acid (AMPA) concentrations were measured on PND15 and PND45. The ovaries and uterus were obtained and weighed on PND45. Ovarian follicular dynamics and uterine morphological features were determined by picrosirius-hematoxylin staining. The proliferation marker Ki67 was evaluated by immunohistochemistry in ovarian and uterine samples. Glyphosate but not AMPA was detected in serum of exposed lambs on PND15, whereas neither glyphosate nor AMPA were detected on PND45. Controls were negative for glyphosate and AMPA on PND15 and PND45. GBH exposure did not affect ovarian or uterine weight. However, on PND45, the ovary of GBH-exposed lambs showed altered follicular dynamics, increased proliferation of granulosa and theca cells, and decreased mRNA expression of FSHR and GDF9, whereas their uterus showed decreased cell proliferation but no alterations in the histomorphology or gene expression. In conclusion, GBH exposure altered the ovarian follicular dynamics and gene expression, and the proliferative activity of the ovaries and uterus of lambs. It is noteworthy that all the adverse effects found in the ovaries and uterus of both GBH-exposed groups were similar, independently of the administration route.

Manservisi et al., 2019

Manservisi, Fabiana, Lesseur, Corina, Panzacchi, Simona, Mandrioli, Daniele, Falcioni, Laura, Bua, Luciano, Manservigi, Marco, Spinaci, Marcella, Galeati, Giovanna, Mantovani, Alberto, Lorenzetti, Stefano, Miglio, Rossella, Andrade, Anderson Martino, Kristensen, David Møbjerg, Perry, Melissa J., Swan, Shanna H., Chen, Jia, & Belpoggi, Fiorella. “The Ramazzini Institute 13-week pilot study glyphosate-based herbicides administered at human-equivalent dose to Sprague Dawley rats: effects on development and endocrine system,” Environmental Health, 2019, 18(1). DOI:10.1186/s12940-019-0453-y.

ABSTRACT:

BACKGROUND: Glyphosate-based herbicides (GBHs) are broad-spectrum herbicides that act on the shikimate pathway in bacteria, fungi, and plants. The possible effects of GBHs on human health are the subject of an intense public debate for both its potential carcinogenic and non-carcinogenic effects, including potential effects on the endocrine system The present pilot study examine whether exposure to GBHs at the dose of glyphosate considered to be “safe” (the US Acceptable Daily Intake – ADI – of 1.75 mg/kg bw/day), starting from in utero life, affect the development and endocrine system across different life stages in Sprague Dawley (SD) rats.

METHODS: Glyphosate alone and Roundup Bioflow, a commercial brand of GBHs, were administered in drinking water at 1.75 mg/kg bw/day to F0 dams starting from the gestational day (GD) 6 (in utero) up to postnatal day (PND) 120. After weaning, offspring were randomly distributed in two cohorts: 8 M + 8F/group animals belonging to the 6-week cohort were sacrificed after puberty at PND 73 ± 2; 10 M + 10F/group animals belonging to the 13-week cohort were sacrificed at adulthood at PND 125 ± 2. Effects of glyphosate or Roundup exposure were assessed on developmental landmarks and sexual characteristics of pups.

RESULTS: In pups, anogenital distance (AGD) at PND 4 was statistically significantly increased both in Roundup treated males and females and in glyphosate-treated males. Age at first estrous (FE) was significantly delayed in the Roundup-exposed group and serum testosterone concentration significantly increased in Roundup-treated female offspring from the 13-week cohort compared to control animals. A statistically significant increase in plasma TSH concentration was observed in glyphosate-treated males compared with control animals as well as a statistically significant decrease in DHT and increase in BDNF in Roundup-treated males. Hormonal status imbalances were more pronounced in Roundup-treated rats after prolonged exposure.

CONCLUSIONS: The present pilot study demonstrate that GBHs exposure, from prenatal period to adulthood, induced endocrine effects and altered reproductive developmental parameters in male and female SD rats. In particular, it was associated with androgen-like effects, including a statistically significant increase of AGDs in both males and females, delay of FE and increased testosterone in female. FULL TEXT

Connolly et al., 2018

Connolly A, Jones K, Basinas I, Galea KS, Kenny L, McGowan P, Coggins MA, “Exploring the half-life of glyphosate in human urine samples,” International Journal of Hygeine and Environmental Health, 2018 (EPub), doi:10.1016/j.ijheh.2018.09.004.

ABSTRACT:

BACKGROUND: The International Agency for Research on Cancer (IARC) has recently classified glyphosate as a Group 2A ‘probably carcinogenic to humans’. Due to this carcinogenic classification and resulting international debate, there is an increased demand for studies evaluating human health effects from glyphosate exposures. There is currently limited information on human exposures to glyphosate and a paucity of data regarding glyphosate’s biological half-life in humans.

OBJECTIVE: This study aims to estimate the human half-life of glyphosate from human urine samples collected from amenity horticulture workers using glyphosate based pesticide products.

METHODS: Full void urine spot samples were collected over a period of approximately 24 h for eight work tasks involving seven workers. The elimination time and estimation of the half-life of glyphosate using three different measurement metrics: the unadjusted glyphosate concentrations, creatinine corrected concentrations and by using Urinary Excretion Rates (UER) (μgL−1, μmol/mol creatinine and UER μgL−1) was calculated by summary and linear interpolation using regression analysis.

RESULTS: This study estimates the human biological half-life of glyphosate as approximately 5 ½, 10 and 7 ¼ hours for unadjusted samples, creatinine corrected concentrations and by using UER (μgL−1, μmol/mol creatinine, UER μgL−1), respectively. The approximated glyphosate half-life calculations seem to have less variability when using the UER compared to the other measuring metrics.

CONCLUSION: This study provides new information on the elimination rate of glyphosate and an approximate biological half-life range for humans. This information can help optimise the design of sampling strategies, as well as assisting in the interpretation of results for human biomonitoring studies involving this active ingredient. The data could also contribute to the development or refinement of Physiologically Based PharmacoKinetic (PBPK) models for glyphosate. FULL TEXT

Jayasumana, 2015b

Jayasumana C, Paranagama P, Agampodi S, Wijewardane C, Gunatilake S, Siribaddana S, “Drinking well water and occupational exposure to Herbicides is associated with chronic kidney disease in Padavi-Sripura, Sri Lanka,” 2015, Environmental Health, 14:6, DOI:10.1186/1476-069X-14-6.

ABSTRACT:

BACKGROUND: The chronic kidney disease of unknown etiology (CKDu) among paddy farmers in was first reported in 1994 and has now become most important public health issue in dry zone of Sri Lanka. The objective was to identify risk factors associated with the epidemic in an area with high prevalence.

METHODS: A case control study was carried out in Padavi-Sripura hospital in Trincomalee district. CKDu patients were defined using health ministry criteria. All confirmed cases (N = 125) fulfilling the entry criteria were recruited to the study. Control selection (N = 180) was done from people visiting the hospital for CKDu screening. Socio-demographic and data related to usage of applying pesticides and fertilizers were studied. Drinking water was also analyzed using ICP-MS and ELISA to determine the levels of metals and glyphosate.

RESULTS: Majority of patients were farmers (N = 107, 85.6%) and were educated up to ‘Ordinary Level’ (N = 92, 73.6%). We specifically analyzed for the effect modification of, farming by sex, which showed a significantly higher risk for male farmers with OR 4.69 (95% CI 1.06-20.69) in comparison to their female counterparts. In the multivariable analysis the highest risk for CKDu was observed among participants who drank well water (OR 2.52, 95% CI 1.12-5.70) and had history of drinking water from an abandoned well (OR 5.43, 95% CI 2.88-10.26) and spray glyphosate (OR 5.12, 95% CI 2.33-11.26) as a pesticide. Water analysis showed significantly higher amount of hardness, electrical conductivity and glyphosate levels in abandoned wells. In addition Ca, Mg, Ba, Sr, Fe, Ti, V and Sr were high in abandoned wells. Surface water from reservoirs in the endemic area also showed contamination with glyphosate but at a much lower level. Glyphosate was not seen in water samples in the Colombo district.

CONCLUSION: The current study strongly favors the hypothesis that CKDu epidemic among farmers in dry zone of Sri Lanka is associated with, history of drinking water from a well that was abandoned. In addition, it is associated with spraying glyphosate and other pesticides in paddy fields. Farmers do not use personnel protective equipments and wears scanty clothing due to heat when spraying pesticides. FULL TEXT

Pallett, 2018

Pallett K, “Engineered Crop Tolerance to Glyphosate and its Impact on the Use of the Herbicide,” Outlooks on Pest Management, December 2018. doi:10.1564/v29_dec_11.

ABSTRACT:

The agricultural importance and particularly the consequences of the use of glyphosate in crops engineered to be tolerant to this non-selective herbicide is discussed in some of the other articles in this special issue of Outlooks on Pest Management. However, a specific article reviewing the science and magnitude of what can be considered as a major scientific development in plant science is justified and is the most important aspect of the success of this herbicide (Duke & Powles, 2008). FULL TEXT

Richmond, 2018

Richmond, Martha E., “Glyphosate: A review of its global use, environmental impact, and potential health effects on humans and other species,” Journal of Environmental Studies and Sciences, Published online 09/28/2018, doi:10.1007/s13412-018-0517-2.

ABSTRACT:

Glyphosate, [N-(phosphonomethyl) glycine], was synthesized in 1950 and patented as a chemical chelator, capable of binding metals such as calcium, magnesium, and manganese. Glyphosate’s ability to bind to manganese was later found to inhibit an enzyme used by plants and bacteria for biosynthesis ofthree amino acids found in all proteins, and the commercial value ofthis property led to the development and marketing of glyphosate as a broad-spectrum herbicide. In 1974, the Monsanto Chemical Company introduced the herbicide as Roundup™, a formulation of glyphosate and adjuvants. Roundup™ was originally used for weed control in specific farming and landscaping operations and around power lines and train tracks. Following introduction of Roundup Ready™ seeds, in the 1990s, glyphosate use increased significantly. Although Monsanto’s patent on glyphosate expired in 2002, the widespread and growing use ofRoundup Ready™ seed globally and competitive glyphosate marketing by other chemical companies have led to glyphosate’s significant increase in the environment. Concerns about potential adverse effects have also grown. While, at present, many regulatory agencies have determined that there is little risk of adverse health effects to the general public or to farmworkers using proper handling techniques, the International Agency for Research on Cancer (IARC) assessing hazard data on glyphosate identified it in 2016 as a category 2A carcinogen (likely to cause human cancer). Response to this classification has been divided: The agribusiness industry has been forceful in its opposition, while other experts support IARC’s classification. The following article examines these issues. It also examines the basis for regulatory decisions, controversies involved, and questions of environmental justice that may or may not be addressed as glyphosate continues to be used. FULL TEXT

Panzacchi et al., 2018

Panzacchi, S., Mandrioli, D., Manservisi, F., Bua, L., Falcioni, L., Spinaci, M., Galeati, G., Dinelli, G., Miglio, R., Mantovani, A., Lorenzetti, S., Hu, J., Chen, J., Perry, M. J., Landrigan, P. J., & Belpoggi, F. “The Ramazzini Institute 13-week study on glyphosate-based herbicides at human-equivalent dose in Sprague Dawley rats: study design and first in-life endpoints evaluation,” Environmental Health, 17(1), 52, 2018. doi:10.1186/s12940-018-0393-y.

ABSTRACT:

BACKGROUND: Glyphosate-based herbicides (GBHs) are the most widely used pesticides worldwide, and glyphosate is the active ingredient of such herbicides, including the formulation known as Roundup. The massive and increasing use of GBHs results in not only the global burden of occupational exposures, but also increased exposure to the general population. The current pilot study represents the first phase of a long-term investigation of GBHs that we are conducting over the next 5 years. In this paper, we present the study design, the first evaluation of in vivo parameters and the determination of glyphosate and its major metabolite aminomethylphosphonic acid (AMPA) in urine.

METHODS: We exposed Sprague-Dawley (SD) rats orally via drinking water to a dose of glyphosate equivalent to the United States Acceptable Daily Intake (US ADI) of 1.75 mg/kg bw/day, defined as the chronic Reference Dose (cRfD) determined by the US EPA, starting from prenatal life, i.e. gestational day (GD) 6 of their mothers. One cohort was continuously dosed until sexual maturity (6-week cohort) and another cohort was continuously dosed until adulthood (13-week cohort). Here we present data on general toxicity and urinary concentrations of glyphosate and its major metabolite AMPA.

RESULTS: Survival, body weight, food and water consumption of the animals were not affected by the treatment with either glyphosate or Roundup. The concentration of both glyphosate and AMPA detected in the urine of SD rats treated with glyphosate were comparable to that observed in animals treated with Roundup, with an increase in relation to the duration of treatment. The majority of glyphosate was excreted unchanged. Urinary levels of the parent compound, glyphosate, were around 100-fold higher than the level of its metabolite, AMPA.

CONCLUSIONS: Glyphosate concentrations in urine showed that most part of the administered dose was excreted as unchanged parent compound upon glyphosate and Roundup exposure, with an increasing pattern of glyphosate excreted in urine in relation to the duration of treatment. The adjuvants and the other substances present in Roundup did not seem to exert a major effect on the absorption and excretion of glyphosate. Our results demonstrate that urinary glyphosate is a more relevant marker of exposure than AMPA in the rodent model. FULL TEXT

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