Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada

Chromatographic Methods for the Determination of Glyphosate in Cereals Together with a Discussion of Its Occurrence, Accumulation, Fate, Degradation, and Regulatory Status

The European Union's recent decision to renew the authorization for the use of glyphosate until 15 December 2033 has stimulated scientific discussion all around the world regarding its toxicity or otherwise for humans. Glyphosate is a chemical of which millions of tons have been used in the last 50 years worldwide to dry out weeds in cultivated fields and greenhouses and on roadsides. Concern has been raised in many areas about its possible presence in the food chain and its consequent adverse effects on health. Both aspects that argue in favor of toxicity and those that instead may indicate limited toxicity of glyphosate are discussed here. The widespread debate that has been generated requires further investigations and field measurements to understand glyphosate's fate once dispersed in the environment and its concentration in the food chain. Hence, there is a need for validated analytical methods that are available to analysts in the field. In the present review, methods for the analytical determination of glyphosate and its main metabolite, AMPA, are discussed, with a specific focus on chromatographic techniques applied to cereal products. The experimental procedures are explained in detail, including the cleanup, derivatization, and instrumental conditions, to give the laboratories involved enough information to proceed with the implementation of this line of analysis. The prevalent chromatographic methods used are LC-MS/MS, GC-MS/SIM, and GC-MS/MS, but sufficient indications are also given to those laboratories that wish to use the better performing high-resolution MS or the simpler HPLC-FLD, HPLC-UV, GC-NPD, and GC-FPD techniques for screening purposes. The concentrations of glyphosate from the literature measured in wheat, corn, barley, rye, oats, soybean, and cereal-based foods are reported, together with its regulatory status in various parts of the world and its accumulation mechanism. As for its accumulation in cereals, the available data show that glyphosate tends to accumulate more in wholemeal flours than in refined ones, that its concentration in the product strictly depends on the treatment period (the closer it is to the time of harvesting, the higher the concentration), and that in cold climates, the herbicide tends to persist in the soil for a long time.

The research landscape concerning environmental factors in neurodevelopmental disorders: Endocrine disrupters and pesticides-A review

In recent years, environmental epidemiology and toxicology have seen a growing interest in the environmental factors that contribute to the increased prevalence of neurodevelopmental disorders, with the purpose of establishing appropriate prevention strategies. A literature review was performed, and 192 articles covering the topic of endocrine disruptors and neurodevelopmental disorders were found, focusing on polychlorinated biphenyls, polybrominated diphenyl ethers, bisphenol A, and pesticides. This study contributes to analyzing their effect on the molecular mechanism in maternal and infant thyroid function, essential for infant neurodevelopment, and whose alteration has been associated with various neurodevelopmental disorders. The results provide scientific evidence of the association that exists between the environmental neurotoxins and various neurodevelopmental disorders. In addition, other possible molecular mechanisms by which pesticides and endocrine disruptors may be associated with neurodevelopmental disorders are being discussed.

Long-lasting developmental effects in rat offspring after maternal exposure to acetamiprid in the drinking water during gestation

Neonicotinoids (NNTs) are a class of insecticides proposed to be safe for pest control in urban, suburban, and agricultural applications. However, little is known about their developmental effects after repeated low-dose exposures during gestation. Here, we tested a dose considered subthreshold for maternal toxicity in rats (6 mg/kg/day) by assessing several morphological, biochemical, and neurobehavioral features in preterm fetuses and developing pups after maternal administration of the NTT acetamiprid (ACP) dissolved in the drinking water during gestational days (GD) 2-19. The exploratory evaluation included monitoring maternal body weight gain, fetal viability, body weight and sex ratio, cephalic length, neonatal body weight and sex ratio, metabolic enzymes in the placenta, maternal blood and fetal liver, and anogenital distance and surface righting response during infancy. We also used the circling training test to study the integrity of the associative-spatial-motor response in adolescence. Results showed no consistent findings indicating maternal, reproductive or developmental toxicity. However, we found ACP effects on maternal body weight gain, placental butyrylcholinesterase activity, and neurobehavioral responses, suggestive of a mild toxic action. Thus, our study showed a trend for developmental susceptibility at a dose so far considered subtoxic. Although the ACP concentration in environmental samples of surface water and groundwater has been mostly reported to be much lower than that used in our study, our results suggest that the ACP point of departure used in current guidelines aimed to prevent developmental effects may need to be verified by complementary sensitive multiple-endpoint testing in the offspring.

The Effect of Pesticide Spray Season and Residential Proximity to Agriculture on Glyphosate Exposure among Pregnant People in Southern Idaho, 2021

BACKGROUND

Glyphosate is one of the most heavily used pesticides in the world, but little is known about sources of glyphosate exposure in pregnant people living in agricultural regions.

OBJECTIVE

Our objective was to evaluate glyphosate exposure during pregnancy in relation to residential proximity to agriculture as well as agricultural spray season.

METHODS

We quantified glyphosate concentrations in 453 urine samples collected biweekly from a cohort of 40 pregnant people in southern Idaho from February through December 2021. We estimated each participant's glyphosate exposure as the geometric mean (GM) of glyphosate concentrations measured in all samples (average n = 11 samples/participant), as well as the GM of samples collected during the pesticide "spray season" (defined as those collected 1 May-15 August; average n = 5 samples/participant) and the "nonspray season" (defined as those collected before 1 May or after 15 August; average n = 6 samples/participant). We defined participants who resided < 0.5 km from an actively cultivated agriculture field to live "near fields" and those residing ≥ 0.5 km from an agricultural field to live "far from fields" (n = 22 and 18, respectively).

RESULTS

Among participants living near fields, urinary glyphosate was detected more frequently and at significantly increased GM concentrations during the spray season in comparison with the nonspray season (81% vs. 55%; 0.228 μ g / L vs. 0.150 μ g / L , p < 0.001 ). In contrast, among participants who lived far from fields, neither glyphosate detection frequency nor GMs differed in the spray vs nonspray season (66% vs. 64%; 0.154 μ g / L vs. 0.165 μ g / L , p = 0.45 ). Concentrations did not differ by residential proximity to fields during the nonspray season (0.154 μ g / L vs. 0.165 μ g / L , for near vs. far, p = 0.53 ).

DISCUSSION

Pregnant people living near agriculture fields had significantly increased urinary glyphosate concentrations during the agricultural spray season than during the nonspray season. They also had significantly higher urinary glyphosate concentrations during the spray season than those who lived far from agricultural fields at any time of year, but concentrations did not differ during the nonspray season. These findings suggest that agricultural glyphosate spray is a source of exposure for people living near fields. https://doi.org/10.1289/EHP12768.

Impact of glyphosate (RoundupTM) on the composition and functionality of the gut microbiome

Glyphosate, the active ingredient in the broad-spectrum herbicide RoundupTM, has been a topic of discussion for decades due to contradictory reports of the effect of glyphosate on human health. Glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) of the shikimic pathway producing aromatic amino acids in plants, a mechanism that suggests that the herbicide would not affect humans as this pathway is not found in mammals. However, numerous studies have implicated glyphosate exposure in the manifestation of a variety of disorders in the human body. This review specifically outlines the potential effect of glyphosate exposure on the composition and functionality of the gut microbiome. Evidence has been building behind the hypothesis that the composition of each individual gut microbiota significantly impacts health. For this reason, the potential of glyphosate to inhibit the growth of beneficial microbes in the gut or alter their functionality is an important topic that warrants further consideration.

Oxidative Stress and Cytotoxicity Induced by Co-Formulants of Glyphosate-Based Herbicides in Human Mononuclear White Blood Cells

The use of genetically modified, glyphosate-resistant crops has led to the widespread application of glyphosate-based herbicides (GBHs), making them one of the most widely used herbicide formulations on the market. To enhance the efficacy of the active ingredient, GBHs used in practice often contain other ingredients marked as inert "adjuvants" or "co-formulants", the toxic properties of which are poorly understood. The objective of this study was to compare the cytotoxic effects of pure glyphosate, three GBHs (Roundup Mega, Fozat 480 and Glyfos) and two co-formulants commonly used in GBHs as assessed via CCK-8 assay, and the extent of their potential oxidative damage as assessed via superoxide dismutase (SOD) assay, in order to reveal the role of adjuvants in the toxicity of the formulations. Our results showed that glyphosate alone did not significantly affect cell viability. In contrast, GBHs and adjuvants induced a pronounced cytotoxic effect from a concentration of 100 μM. SOD activity of cells treated with GBHs or adjuvants was significantly lower compared to cells treated with glyphosate alone. This suggests that the adjuvants in GBHs are responsible for the cytotoxic effects of the formulations through the induction of oxidative stress.

Toxicity assessment and DNA repair kinetics in HEK293 cells exposed to environmentally relevant concentrations of Glyphosate (Roundup® Control Max)

Glyphosate is a systemic, non-selective, pre and post-emergence wide range herbicide. In 2015, IARC classified Glyphosate as "a probable carcinogenic agent for humans". The aim of this study was to evaluate the cytotoxicity and genotoxicity of the commercial formulation of glyphosate (Roundup® Control Max) at environmentally relevant concentrations and measure the potential effect of this herbicide over the cell capacity to repair DNA damage. HEK293 cells were exposed to 5 concentrations of Roundup® Control Max equivalent to 0.7; 7; 70; 700 and 3,500 μg/L glyphosate acid, for 1, 4 and 24 h. Cytotoxicity was quantified by the Trypan Blue staining method and by the MTT assay, while genotoxicity and evaluation of DNA damage repair kinetics were analyzed through the alkaline comet assay. In all treatments, cell viability was higher than 80%. The three highest glyphosate concentrations-70 μg/L, 700 μg/L, and 3,500 μg/L-increased levels of DNA damage compared to the control at the three exposure times tested. Finally, concerning the kinetics of DNA damage repair, cells initially exposed to 3,500 μg/L of glyphosate for 24 h were unable to repair the breaks in DNA strands even after 4 h of incubation in culture medium. The present study demonstrated for the first time that Roundup® Control Max may induce genetic damage and cause alterations in the DNA repair system in human embryonic kidney cells even at concentrations found in blood and breast milk of people exposed through residues of the herbicide in food, which values have been poorly assessed or not studied yet according to the existent literature.

Estrogens and endocrine-disrupting chemicals differentially impact the bioenergetic fluxes of mammary epithelial cells in two- and three-dimensional models

Due to its sensitivity to hormonal signaling, the mammary gland is often referred to as a sentinel organ for the study of endocrine-disrupting chemicals (EDCs), environmental pollutants that can interfere with the estrogen signaling pathway and induce mammary developmental defects. If and how EDCs impact mammary epithelial cell metabolism has not yet been documented. Herein, to study how estrogens and EDCs modulate mammary gland metabolism, we performed bioenergetic flux analyses using mouse mammary epithelial organoids compared to cells grown in monolayer culture. Several EDCs were tested, including bisphenol A (BPA), its close derivative BPS, a new BPA replacement copolyester called TritanTM, and the herbicide glyphosate. We report that estrogens reprogrammed mammary epithelial cell metabolism differently when grown in two- and three-dimensional models. Specific EDCs were also demonstrated to alter bioenergetic fluxes, thus identifying a new potential adverse effect of these molecules. Notably, organoids were more sensitive to low EDC concentrations, highlighting them as a key model for screening the impact of various environmental pollutants. Mechanistically, transcriptomic analyses revealed that EDCs interfered with the regulation of estrogen target genes and the expression of metabolic genes in organoids. Furthermore, co-treatment with the anti-estrogen fulvestrant blocked these metabolic impacts of EDCs, suggesting that, at least partially, they act through modulation of the estrogen receptor activity. Finally, we demonstrate that mammary organoids can be used for long-term studies on EDC exposure to study alterations in organogenesis/morphogenesis and that past pregnancies can modulate the sensitivity of mammary epithelial organoids to specific EDCs. Overall, this study demonstrates that estrogens and EDCs modulate mammary epithelial cell metabolism in monolayer and organoid cultures. A better understanding of the metabolic impacts of EDCs will allow a better appreciation of their adverse effects on mammary gland development and function.

Improved Chromatography and MS-Based Detection of Glyphosate and Aminomethylphosphonic Acid Using iTrEnDi

Glyphosate (GLY), a synthetic, nonselective systemic herbicide that is particularly effective against perennial weeds, is the most used weedkiller in the world. There are growing concerns over GLY accumulation in the environment and the attendant human health-associated risks, and despite increased attention in the media, GLY and its breakdown product aminomethylphosphonic acid (AMPA) remain elusive to many analytical strategies. Chemical derivatization coupled with high-performance liquid chromatography-mass spectrometry (HPLC-MS) addresses the challenge of quantifying low levels of GLY and AMPA in complex samples. Here we demonstrate the use of in situ trimethylation enhancement using diazomethane (iTrEnDi) to derivatize GLY and AMPA into permethylated products ([GLY^Tr]⁺ and [AMPA^Tr]⁺, respectively) prior to analysis via HPLC-MS. iTrEnDi produced quantitative yields and resulted in a 12-340-fold increases in HPLC-MS-based sensitivity for [GLY^Tr]⁺ and [AMPA^Tr]⁺, respectively, compared with underivatized counterparts. The limits of detection of derivatized compounds were found to be 0.99 ng/L for [GLY^Tr]⁺ and 1.30 ng/L for [AMPA^Tr]⁺, demonstrating significant sensitivity improvements compared to previously established derivatization techniques. iTrEnDi is compatible with the direct derivatization of Roundup formulations. Finally, as proof of principle, a simple aqueous extraction followed by iTrEnDi enabled the detection of [GLY^Tr]⁺ and [AMPA^Tr]⁺ on the exterior of field-grown soybeans that were sprayed with Roundup. Overall, iTrEnDi ameliorates issues relating to low proton affinity and chromatographic retention, boosting HPLC-MS-based sensitivity and enabling the elucidation of elusive analytes such as GLY and AMPA within agricultural systems.

Urinary concentrations and determinants of glyphosate and glufosinate in pregnant Canadian participants in the MIREC study

BACKGROUND

Glyphosate is the most widely applied herbicide in agriculture. Glufosinate is a broad spectrum herbicide used to manage glyphosate-resistant weeds. Despite the widespread use of these herbicides, biomonitoring data - which inform risk assessment and management - are sparse.

OBJECTIVES

To identify determinants of urinary concentrations of these herbicides and their metabolites in pregnancy.

METHODS

We measured urinary concentrations of glyphosate, glufosinate, and their primary metabolites aminomethylphosphonic acid (AMPA) and 3-methylphosphinicopropionic acid (3-MPPA) in a single spot urine specimen collected during the first trimester of pregnancy from the Maternal-Infant Research on Environmental Chemicals (MIREC) study. MIREC recruited about 2000 pregnant women from 10 Canadian cities between 2008 and 2011. We used UItra-Performance Liquid Chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) with sensitive limits of detection to quantify analyte concentrations. We examined urinary concentrations according to maternal sociodemographics, sample collection characteristics, reported pesticide use, and consumption of fruits, vegetables, legumes, and grain products. We used ANOVA models with specific gravity-standardized chemical concentrations as the dependent variable to determine associations with maternal and sample determinants.

RESULTS

Among women with biobanked urine samples (n = 1829-1854), 74% and 72% had detectable concentrations of glyphosate and AMPA, respectively. In contrast, one and six percent of women had detectable concentrations of glufosinate and 3-MPPA, respectively. The specific gravity-standardized geometric mean (95% CI) concentrations of glyphosate and AMPA were 0.112 (0.099-0.127) μg/L and 0.159 (0.147-0.172) μg/L, respectively. We observed a dose-response relationship between consumption of whole grain bread and higher urinary glyphosate concentrations. Season of urine collection and self-reported pesticide use were not associated with increased concentrations of any analyte.

CONCLUSIONS

We detected glyphosate and AMPA in the majority of pregnant women from this predominantly urban Canadian cohort. Diet was a probable route of exposure.

Improved Method for the Detection of Highly Polar Pesticides and Their Main Metabolites in Foods of Animal Origin: Method Validation and Application to Monitoring Programme

The application of polar pesticides in agricultural production has been of great interest due to their low costs and their high effectiveness. For this reason, the possibility of their transfer to foods of animal origin is of great concern for human health. The manuscript describes the implementation and validation of an analytical method to detect polar pesticides, at regulatory levels, in three foods of animal origin, including bovine fat, chicken eggs, and cow milk. The method was fully validated to detect glyphosate, glufosinate, and their respective metabolites in the above-mentioned foods obtaining fit-for-purpose sensitivity, recoveries (76–119%), repeatability (≤20%), within-laboratory reproducibility (≤20%), and experimental measurement uncertainty less than 50% as required by the SANTE/11312/2021 criteria. Given the satisfactory results, the applicability of the method to additional molecules belonging to the same category (AMPA, cyanuric acid, ethephon, fosetyl aluminum, HEPA, maleic hydrazide, and N-acetyl-glyphosate) was also evaluated in order to meet possible future requests. Finally, the implemented method was applied to analyse samples over the period of March 2021 to August 2022 from two Italian regions (Umbria and Marche) within the national monitoring programme. In agreement with previously available data, none of the samples analysed showed the presence of glyphosate and glufosinate at levels above the legal limit.

Glyphosate disturbs various epigenetic processes in vitro and in vivo - A mini review

Glyphosate in the concentrations corresponding to environmental or occupational exposure has been shown to induce epigenetic changes potentially involved in carcinogenesis. This substance (1) changes the global methylation in various cell types and organisms and is responsible for the methylation of different promoters of individual genes, such as TP53 and P21 in human PBMCs, (2) decreases H3K27me3 methylation and H3 acetylation and increases H3K9 methylation and H4 acetylation in rats, (3) increases the expression of P16, P21, CCND1 in human PBMCs, and the expression of EGR1, JUN, FOS, and MYC in HEK293 cells, but decreases TP53 expression in human PBMCs, (4) changes the expression of genes DNMT1, HDAC3, TET1, TET2, TET3 involved in chromatin architecture, e.g. in fish Japanese medaka, (5) alters the expression of various small, single-stranded, non-coding RNA molecules engaged in post-transcriptional regulation of gene expression, such as miRNA 182-5p in MCF10A cells, miR-30 and miR-10 in mammalian stem cells, as well as several dozen of murine miRNAs. Epigenetic changes caused by glyphosate can persist over time and can be passed on to the offsprings in the next generation; in the third generation they can result in some disorders development, such as prostate disease or obesity. Some epigenetic mechanisms have indicated a potential risk of breast cancer development in human as a result of the exposure to glyphosate. It should be emphasized that the majority of reported epigenetic changes have not yet been associated with the final metabolic effects, which may depend on many other factors.

The Ecotoxicology of Microbial Insecticides and Their Toxins in Genetically Modified Crops: An Overview

The use of microbial insecticides and their toxins in biological control and transgenic plants has increased their presence in the environment. Although they are natural products, the main concerns are related to the potential impacts on the environment and human health. Several assays have been performed worldwide to investigate the toxicity or adverse effects of these microbial products or their individual toxins. This overview examines the published data concerning the knowledge obtained about the ecotoxicity and environmental risks of these natural pesticides. The data presented show that many results are difficult to compare due to the diversity of measurement units used in the different research data. Even so, the products and toxins tested present low toxicity and low risk when compared to the concentrations used for pesticide purposes. Complementary studies should be carried out to assess possible effects on human health.

Investigation of the toxicity of a glyphosate-based herbicide in a human liver cell line: Assessing the involvement of Nrf2 pathway and protective effects of vitamin E and α-lipoic acid

Glyphosate-based herbicides (GBHs) are the most widely used herbicides all over the world and has gained more attention in recent years because of health safety concerns. In this study, Roundup, one of the most popular glyphosate formulations, was used to evaluate cytotoxic, oxidative stress and apoptosis inducing effects of GBHs in a human hepatocellular cell line (HepG2). Roundup was shown to significantly increase cellular reactive oxygen species (ROS) levels, which lead to activation of the nuclear factor-erythroid-2-related factor 2 (Nrf2) antioxidant defense pathway including reduced levels of heme oxygenase 1 (HO-1). Furthermore, Roundup was found to induce apoptosis and further analysis confirmed involvement of a mitochondrial-dependent pathway verified by increased Bax/Bcl-2 ratios. Investigation of the protective effects of antioxidants vitamin E (Vit E) and α-lipoic acid (LA) against Roundup toxicity showed that both antioxidants significantly reduced the cytotoxicity, ROS formation, HO-1 downregulation, and apoptosis and that Vit E did so more efficiently than LA. In conclusion, our findings highlight the ROS producing and apoptosis inducing effects associated with GBHs, the activation of Nrf2 pathway as a defense mechanism and the protective effects of Vit E and LA against GBH toxicity.

Airborne polar pesticides in rural and mountain sites of North-Eastern Italy: An emerging air quality issue

North-Eastern Italy and in particular Veneto Region, stands out as a major centre of agriculture and viticulture which has rapidly expanded in the last decade with high productivity indexes. In this context, assessing atmospheric pollution caused by crop spraying with pesticides in rural areas and their transport to high-altitude remote sites is crucial to provide a basis for understanding possible impacts on the environment and population health. We aim to improve existing methods with a highly sensitive technique by using high pressure anion exchange chromatography coupled to a triple quadrupole mass spectrometer. Thus, a total of fourteen polar pesticides were determined in aerosol samples collected from August to December 2021 at Roncade (Venetian plain) and Col Margherita Observatory (Dolomites). The observatory was chosen as the background site as it is representative of the surrounding alpine region. Some samples revealed a substantial amount of cyanuric acid mainly at Roncade (mean concentration of 10 ± 10 ng m^-3), glyphosate and fosetyl-aluminium (0.1 ± 0.2 and 0.1 ± 0.1 ng m^-3, respectively). Surprisingly, some pesticides have been also found at Col Margherita, a high mountain background site, with concentrations an order of magnitude lower than at Roncade. This is the first time that fourteen polar pesticides have been assessed in the aerosol phase of the Po' Valley and detected at a high-altitude remote site, and consequently this study provides the first data on their occurrences in Italian aerosols. It represents a basis for the assessment of risks for humans.

Detection of glyphosate residues in feed, saliva, urine and faeces from a cattle farm: a pilot study

Forty-two samples of feed, saliva, urines, and faeces collected from a cattle farm were investigated with the aim to evaluate the occurrence of glyphosate in faeces, urine and saliva. Glyphosate in the feed was also quantified to understand how it was assimilated by mammals. All cows excreted glyphosate in their faeces at concentrations between 57 and 983 ng g-1. In contrast, only 55% of urine and one sample of saliva tested positive. Most of the feeds demonstrated a non-negligible presence of glyphosate. In particular, a silage containing soybeans from genetically modified cultivation showed a concentration one order of magnitude higher than the other feeds. This study aims to provide the first complete determination of glyphosate in a cattle farm, considering the possible re-entry into the environment through the spreading of liquid and solid sewage and its possible impact on groundwater.

Determination of glyphosate, aminomethylphosphonic acid, and glufosinate in river water and sediments using microwave-assisted rapid derivatization and LC-MS/MS

Glyphosate (N-phosphonomethyl glycine) and glufosinate (ammonium dl-homoalanin- 4-methyl phosphinate) are nonselective, broad-spectrum, and highly polar herbicides that are wildly used for weed control in aquatic systems and vegetation control in non-crop areas. Aminomethylphosphonic acid (AMPA) is the major degradation product of glyphosate. To address the concerns to its environmental residue and the possible adverse effects, the analytical methods by using microwave-assisted derivatization were developed for determining glyphosate, AMPA, and glufosinate in river water and sediments. The methods applied the 9-fluorenylmethyloxycarbonyl chloride (FMOC-Cl) derivatization for the analytes. The microwave heating is first-time applied to reduce the FMOC-reaction time of glyphosate, AMPA, and glyphosate in the environmental samples to less than 2.5 min. The microwave-assisted methods were successfully validated for river water and sediment. The linear ranges of 7.8-2000.0 ng/L and 0.78-100.0 ng/g were achieved by using 10 mL of water and 2 g of sediments. Glyphosate was found in 30/32% and 25/32% of 32 water and 32 sediments at 27.1-1353.9 ng/L and 2.4-189.6 ng/g levels. AMPA was found in 30/32% and 30/32% of 32 water and 32 sediments at 60.2-1509.0 ng/L and 1.8-233.6 ng/g levels. Glyphosate was found in 10/32% of 32 water at 14.8-503.1 ng/L levels. No glufosinate residue was observed for 32 sediments. The residues of glyphosate and AMPA were wildly detected in the river waters and sediments near the agricultural regions, and glufosinate was less detected. This is the first study that reported herbicide levels in water and sediment from Taiwan rural areas using microwave-assisted rapid derivatization, useful information for environmental management.

Red-Emitting Polymerizable Guanidinium Dyes as Fluorescent Probes in Molecularly Imprinted Polymers for Glyphosate Detection

The development of methodologies to sense glyphosate has gained momentum due to its toxicological and ecotoxicological effects. In this work, a red-emitting and polymerizable guanidinium benzoxadiazole probe was developed for the fluorescence detection of glyphosate. The interaction of the fluorescent probe and the tetrabutylammonium salt of glyphosate was studied via UV/vis absorption and fluorescence spectroscopy in chloroform and acetonitrile. The selective recognition of glyphosate was achieved by preparing molecularly imprinted polymers, able to discriminate against other common herbicides such as 2,4-dichlorophenoxyacetic acid (2,4-D) and 3,6-dichloro-2-methoxybenzoic acid (dicamba), as thin layers on submicron silica particles. The limits of detection of 4.8 µM and 0.6 µM were obtained for the sensing of glyphosate in chloroform and acetonitrile, respectively. The reported system shows promise for future application in the sensing of glyphosate through further optimization of the dye and the implementation of a biphasic assay with water/organic solvent mixtures for sensing in aqueous environmental samples.

Glufosinate-Ammonium Induced Aberrant Histone Modifications in Mouse Sperm Are Concordant With Transcriptome in Preimplantation Embryos

Glufosinate-ammonium (GLA) is a widely used herbicide with emerging concern over its male reproductive toxicity. Abnormalities in sperm histone modification induced by GLA exposure observed in our previous study aroused our interest in whether such alterations could further affect embryonic gene expression. Here we administered adult male mice with 0.2 mg/kg⋅day of GLA for 5 weeks to collect their sperm or 4-cell embryos after copulation. Cleavage Under Targets and Tagmentation (CUT&Tag) sequencing showed alterations of sperm H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 acetylation (H3K27ac), which are active histone modification marks involved in embryo development, while RNA sequencing identified differentially expressed genes in 4-cell embryos. Differentially H3K4me3 and H3K27ac occupied regions were mainly distributed at the gene promoters and putative enhancers, and were enriched in pathways related to the immune system and nervous system. Integrative analysis of these sequencing data showed that genes such as Mgl2 with increased H3K4me3 and H3K27ac in sperm were up-regulated in embryos, and vice versa for genes such as Dcn. Additionally, differentially occupied H3K4me3 and H3K27ac in sperm were linked to gene expression changes in both paternal and maternal alleles of 4-cell embryos. In conclusion, GLA-induced changes in sperm H3K4me3 and H3K27ac are concordant with gene expression in preimplantation embryos, which might further affect embryo development and offspring health.

The relationship between pesticide exposure during critical neurodevelopment and autism spectrum disorder: A narrative review

Agricultural pesticides have been one of the most extensively used compounds throughout the world. The main sources of contamination for humans are dietary intake and occupational exposure. The impairments caused by agricultural pesticide exposure have been a significant global public health problem. Recent studies have shown that low-level agricultural pesticide exposure during the critical period of neurodevelopment (pregnancy and lactation) is closely related to autism spectrum disorder (ASD). Inhibition of acetylcholinesterase, gut microbiota, neural dendrite morphology, synaptic function, and glial cells are targets for the effects of pesticides during nervous system development. In the present review, we summarize the associations between several highly used and frequently studied pesticides (e.g., glyphosate, chlorpyrifos, pyrethroids, and avermectins) and ASD. We also discusse future epidemiological and toxicological research directions on the relationship between pesticides and ASD.

Effects of glufosinate-ammonium on male reproductive health: Focus on epigenome and transcriptome in mouse sperm

Glufosinate-ammonium (GLA) is a widely used herbicide with emerging concern over its neural and reproductive toxicity. To uncover potential effects of GLA on male reproductive health in mammals, adult male C57BL/6J mice were administered 0.2 mg/kg·d GLA for 5 weeks. After examination on fertility, testis histology and semen quality in the GLA group, we performed deep sequencing to identify repressive epigenetic marks including DNA methylation and histone modifications (H3K27me3 and H3K9me3), together with mRNA transcript levels in sperm. Then, we integrated multi-omics sequencing data to comprehensively explore GLA-induced epigenetic and transcriptomic alterations. We found no significant difference either on fertility, testis histology or semen quality-related indicators. As for epigenome, the protein level of H3K27me3 was significantly increased in GLA sperm. Next generation sequencing showed alterations of these epigenetic marks and extensive transcription inhibition in sperm. These differential repressive marks were mainly distributed at intergenic regions and introns. According to results by Gene Ontology enrichment analysis, both differentially methylated and expressed genes were mainly enriched in pathways related to synapse organization. Subtle differences in genomic imprinting were also observed between the two groups. These results suggested that GLA predominantly impaired sperm epigenome and transcriptome in mice, with little effect on fertility, testis histology or semen quality. Further studies on human sperm using similar strategies need to be conducted for a better understanding of the male reproductive toxicity of GLA.

Environmental fate of Bt proteins in soil: Transport, adsorption/desorption and degradation

During the production and application of Bacillus thuringiensis (Bt) transgenic crops, large doses of insecticidal Bt toxic proteins are expressed continuously. The multi-interfacial behaviors of Bt proteins entering the environment in multi-media affects their states of existence transformation, transport and fate as well as biological and ecological impacts. Because both soil matrix and organisms will be exposed to Bt proteins to a certain extent, knowledge of the multi-interfacial behaviors and affecting factors of Bt proteins are vital not only for understanding the source-sink distribution mechanisms, predicting their bio-availability, but also for exploring the soil safety and environmental problems caused by the interaction between Bt proteins and soil matrix. This review summarized and analyzed various internal and external factors that affect the adsorption/ desorption and degradation of Bt proteins in the environment, so as to understand the multi-interfacial behaviors of Bt proteins. In addition, the reasons of concentration changes of Bt proteins in soil are discussed. This review will also discuss the existing knowledge of the combined effects of Bt proteins and other pollutants in environment. Finally, discussing the factors that should be considered when assessing the environmental risk of Bt proteins, thus to further improve the understanding of the environmental fate of Bt proteins.

Effects of transgenic Bacillus Thuringiensis maize (2A-7) on the growth and development in rats

This study aimed to determine the effects of genetically modified insect-resistant maize (2A-7) on the growth and development in developing rats. Rats were fed a diet formulated with 2A-7 maize and were compared with rats fed a diet formulated with non-transgenic maize (CK group) and rats fed AIN-93G diet (BC group). 2A-7 maize was formulated into diets at ratios of 82.4% (H group) and 20.6% (L group); non-transgenic maize was formulated into diets at a ratio of 82.4%. From the first day of pregnancy, adult rats were divided into four groups and fed with the above four diets, respectively. Weaning on postnatal day 21, the diets of offspring were consistent with their parents. The results showed that body weight, hematology, serum biochemistry, organ weight, organ coefficients and allergenicity of offspring fed with 2A-7 maize were comparable with those in the CK and BC groups. In physiological and behavioral development experiments, there was no statistically significant difference among groups. Although mCry1Ab proteins were detected in organs and serum, no histopathological changes were observed among groups. In conclusion, A-7 maize cause no treatment-related adverse effects on offspring, indicating that 2A-7 maize is safe for developing rats.

Trends in science on glyphosate toxicity: a scientometric study

As part of the most used herbicides, glyphosate is the most successful ingredient of agrochemical companies. The main objective of this study was to demonstrate research trends related to the glyphosate toxicity and its main effects on human and environmental health. For this purpose, 443 articles published, from 1995 to 2020, on the platform Web of Science™ Thomson Reuters were selected. The main toxicity results related in literature are genotoxicity, cytotoxicity, and endocrine disruption. The environmental effects come mostly from the contamination of groundwater and soils. Several studies have concluded that herbicide concentrations right below the official safety limits induced toxic effects. The results presented a highlighted harmful effect of glyphosate on both human and environmental health. It has been observed that countries where publish the most about the glyphosate toxicity are great investors in large-scale agriculture. It is important to ponder that these countries are in a route of ecosystem exploitation that includes not only fauna and flora, but also human beings. Unfortunately, science does not provide concise data for these pesticide disapproval in the global consumer market. It is necessary to search sustainable global interest alternatives to increase agriculture production based on peoples' food sovereignty.

Advances in the Immunoassays for Detection of Bacillus thuringiensis Crystalline Toxins

Insect-resistant genetically modified organisms have been globally commercialized for the last 2 decades. Among them, transgenic crops based on Bacillus thuringiensis crystalline (Cry) toxins are extensively used for commercial agricultural applications. However, less emphasis is laid on quantifying Cry toxins because there might be unforeseen health and environmental concerns. Immunoassays, being the preferred method for detection of Cry toxins, are reviewed in this study. Owing to limitations of traditional colorimetric enzyme-linked immunosorbent assay, the trend of detection strategies shifts to modified immunoassays based on nanomaterials, which provide ultrasensitive detection capacity. This review assessed and compared the properties of the recent advances in immunoassays, including colorimetric, fluorescence, chemiluminescence, surface-enhanced Raman scattering, surface plasmon resonance, and electrochemical approaches. Thus, the ultimate aim of this study is to identify research gaps and infer future prospects of current approaches for the development of novel immunosensors to monitor Cry toxins in food and the environment.

Glyphosate and AMPA Induce Alterations in Expression of Genes Involved in Chromatin Architecture in Human Peripheral Blood Mononuclear Cells (In Vitro)

We have determined the effect of glyphosate and aminomethylphosphonic acid (AMPA) on expression of genes involved in chromatin architecture in human peripheral blood mononuclear cells (PBMCs). The cells were incubated with glyphosate and AMPA in the concentrations ranging from 0.5 to 100 μM and from 0.5, to 250 μM, respectively. The expression profile of the following genes by quantitative Real-Time PCR was evaluated: Genes involved in the DNA methylation (DNMT1, DNMT3A) and DNA demethylation process (TET3) and those involved in chromatin remodeling: genes involved in the modification of histone methylation (EHMT1, EHMT2) and genes involved in the modification of histone deacetylation (HDAC3, HDAC5). Gene profiling showed that glyphosate changed the expression of DNMT1, DMNT3A, and HDAC3, while AMPA changed the expression of DNMT1 and HDAC3. The results also revealed that glyphosate at lower concentrations than AMPA upregulated the expression of the tested genes. Both compounds studied altered expression of genes, which are characteristic for the regulation of transcriptionally inactive chromatin. However, the unknown activity of many other proteins involved in chromatin structure regulation prevents to carry out an unambiguous evaluation of the effect of tested xenobiotics on the studied process. Undoubtedly, we have observed that glyphosate and AMPA affect epigenetic processes that regulate chromatin architecture.

Determination of glyphosate, glufosinate and their major metabolites in urine by the UPLC-MS/MS method applicable to biomonitoring and epidemiological studies

The preoccupation concerning glyphosate (GLYP) has rapidly grown over recent years, and the availability of genetically modified crops that are resistant to GLYP or glufosinate (GLUF) has increased the use of these herbicides. The debate surrounding the carcinogenicity of GLYP has raised interest and the desire to gain information on the level of exposure of the population. GLYP and aminomethylphosphonic acid (AMPA) are commonly simultaneously analysed. GLUF is sometimes also monitored, but its major metabolite, 3-[hydroxy(methyl)phosphinoyl]propionic acid (3MPPA), is rarely present in the method. Using a pentafluorobenzyl derivative to extract the analytes from human urine, we present a method that contains four important analytes to monitor human exposure to GLYP and GLUF. The use of the flash freeze technique speeds up the extraction process and requires less organic solvent than conventional liquid-liquid extraction. The limits of detection in the low μg/L range enable the use of this method for epidemiological studies. The results obtained for 35 volunteers from the Quebec City area are presented with the results from multiple interlaboratory comparisons (G-EQUAS, HBM4EU and OSEQAS). This methodology is currently being used in the Maternal-Infant Research on Environmental Chemicals (MIREC-ENDO) study and in the Canadian Health Measures Survey (CHMS).

Assessment of Glyphosate Impact on the Agrofood Ecosystem

Agro-industries should adopt effective strategies to use agrochemicals such as glyphosate herbicides cautiously in order to protect public health. This entails careful testing and risk assessment of available choices, and also educating farmers and users with mitigation strategies in ecosystem protection and sustainable development. The key to success in this endeavour is using scientific research on biological pest control, organic farming and regulatory control, etc., for new developments in food production and safety, and for environmental protection. Education and research is of paramount importance for food and nutrition security in the shadow of climate change, and their consequences in food production and consumption safety and sustainability. This review, therefore, diagnoses on the use of glyphosate and the associated development of glyphosate-resistant weeds. It also deals with the risk assessment on human health of glyphosate formulations through environment and dietary exposures based on the impact of glyphosate and its metabolite AMPA-(aminomethyl)phosphonic acid-on water and food. All this to setup further conclusions and recommendations on the regulated use of glyphosate and how to mitigate the adverse effects.

Environment permissible concentrations of glyphosate in drinking water can influence the fate of neural stem cells from the subventricular zone of the postnatal mouse

The developing nervous system is highly vulnerable to environmental toxicants especially pesticides. Glyphosate pesticide induces neurotoxicity both in humans and rodents, but so far only when exposed to higher concentrations. A few studies, however, have also reported the risk of general toxicity of glyphosate at concentrations comparable to allowable limits set up by environmental protection authorities. In vitro data regarding glyphosate neurotoxicity at concentrations comparable to maximum permissible concentrations in drinking water is lacking. In the present study, we established an in vitro assay based upon neural stem cells (NSCs) from the subventricular zone of the postnatal mouse to decipher the effects of two maximum permissible concentrations of glyphosate in drinking water on the basic neurogenesis processes. Our results demonstrated that maximum permissible concentrations of glyphosate recognized by environmental protection authorities significantly reduced the cell migration and differentiation of NSCs as demonstrated by the downregulation of the expression levels of the neuronal ß-tubulin III and the astrocytic S100B genes. The expression of the cytoprotective gene CYP1A1 was downregulated whilst the expression of oxidative stresses indicator gene SOD1 was upregulated. The concentration comparable to non-toxic human plasma concentration significantly induced cytotoxicity and activated Ca2+ signalling in the differentiated culture. Our findings demonstrated that the permissible concentrations of glyphosate in drinking water recognized by environmental protection authorities are capable of inducing neurotoxicity in the developing nervous system.

Flawed scientific studies block progress and sow confusion

Research in crop science in recent years has advanced at an unprecedented rate, and the intermingling of old and new crop breeding technologies has made the term "genetically modified" - and its variant, Genetically Modified Organism, or "GMO" - virtually obsolete. A kind of pseudo-category, it is primarily used pejoratively to refer to the use of the newest, most precise, most predictable, molecular genetic techniques. Prodigious amounts of time, effort and care have been expended to ensure that crops developed for commercialization using molecular techniques are safe, and that new traits are beneficial. Â Yet, despite these advances, some skepticism persists about them, partly due to the publication of fraudulent, poorly designed, and biased studies by a few "rogue scientists" whose intention is to contaminate the scientific literature and sow mistrust about molecular genetic modification among regulators and the public. We discuss how such flawed studies make it to publication and how the scientific community can combat such disinformation.

Prenatal exposure to glufosinate ammonium disturbs gut microbiome and induces behavioral abnormalities in mice

Glufosinate ammonium (GLA) is a widely used organophosphate herbicide, which could be commonly detected in body fluids of both pregnant women and newborns. Existing evidences indicate that GLA has reproductive toxicity, while data concerning the effects of prenatal GLA exposure on neurodevelopment is rather limited. Here we employed a mouse model exposed to GLA prenatally. Reduced locomotor activity, impaired memory formation and autism-like behaviors were observed in the treatment group. Marked alteration in gut microbiome of the treatment offspring mice could be found at 4th week, and seemed to recover over time. Fecal metabolomics analysis indicated remarkable changes in microbiome-related metabolism in the treatment group, which could be the cause of behavioral abnormality in mice. Present study suggested that prenatal exposure to GLA disturbed gut microbiome and metabolism, and thereby induced behavioral abnormalities in mice.

Glyphosate affects methylation in the promoter regions of selected tumor suppressors as well as expression of major cell cycle and apoptosis drivers in PBMCs (in vitro study)

We have determined the effect of glyphosate on selected epigenetic parameters and major cell cycle drivers in human peripheral blood mononuclear cells (PBMCs). The cells were incubated with glyphosate at 0.5, 10 and 100 μM. The analysis included: global DNA methylation, methylation in the promoter regions of tumor suppressor genes (P16, P21, TP53) and proto-oncogenes (BCL2, CCND1) by the Real-Time PCR and the expression profile of the indicated genes by Real-Time PCR. The obtained results have revealed significant reduction of global DNA methylation level in PBMCs exposed to glyphosate. Tested compound changed methylation pattern of the P21 and TP53 suppressor gene promoters, but in case of other analyzed genes: P16, BCL2 and CCND1 we did not identify any statistically significant changes. Gene profiling showed that glyphosate changed the expression of genes involved in the regulation of cell cycle and apoptosis. Glyphosate decreased expression of P16 and TP53 as well as an increase in the expression of BCl2, CCND1 and P21. Summing up, our results have shown a potential disturbance in methylation processes and gene expression in human PBMCs exposed to glyphosate, but the observed changes do not prejudge about the final metabolic effects, which are depended on many other factors.

Effects of glyphosate exposure on human health: Insights from epidemiological and in vitro studies

Glyphosate (GLY) is a broad-spectrum, post-emergent, non-selective and synthetic universal herbicide, whose commercial formulations are referred to as glyphosate-based-herbicides (GBHs). These chemicals and their metabolites can be found in soil, air, water, as well as groundwater and food products. This review summarizes to summarize current in vitro and epidemiological studies investigating the effects of GLY exposure on human health. Recent human cell studies have reported several GLY and GBH toxicological effects and have contributed to a better understanding of the deleterious consequences associated with their exposure. However, these detrimental effects are dependent on the cell type, chemical composition, as well as magnitude and time of exposure, among other factors. Moreover, the deleterious effects of GLY exposure on human health were observed in epidemiological studies; however, most of these studies have not determined the GLY dosage to confirm a direct effect. While GLY toxicity is clear in human cells, epidemiological studies investigating individuals exposed to different levels of GLY have reported contradictory data. Therefore, based on currently available in vitro and epidemiological data, it is not possible to confirm the complete safety of GLY use, which will require additional comprehensive studies in animal models and humans.

Production and characterization of a single-chain variable fragment antibody from a site-saturation mutagenesis library derived from the anti-Cry1A monoclonal antibody

There are plenty of applications of Cry1A toxins (Cry1Aa, Cry1Ab, Cry1Ac) in genetically modified crops, and it is necessary to establish corresponding detection methods. In this study, a single-chain variable fragment (scFv) with high affinities to Cry1A toxins was produced. First, the variable regions of heavy (V_H) and light chain (V_L) were amplified from hybridoma cell 5B5 which secrete anti-Cry1A monoclonal antibody (mAb) and then spliced into scFv-5B5 by overlap extension polymerase chain reaction (SOE-PCR). Subsequently, site-saturation mutagenesis was performed after homology modeling and molecular docking, which showed that asparagine³⁵, phenylalanine³⁶, isoleucine¹⁰⁴, tyrosine¹⁰⁵, and serine¹⁹⁶, respectively, located in V_H complementarity-determining region (CDR1 and CDR3) and V_L framework region (FR3) were key amino acid sites. Then, the mutagenesis scFv library (1.35 × 10⁵ CFU/mL) was constructed and a mutant scFv-2G12 with equilibrium dissociation constant (K_D) value of 9.819 × 10^-9 M against Cry1Ab toxin, which was lower than scFv-5B5 (2.025 × 10^-8 M) was obtained by biopanning. Then, enzyme-linked immunosorbent assay (ELISA) was established with limit of detection (LOD) and limit of quantitation (LOQ) of 4.6-9.2 and 11.1-17.1 ng mL^-1 respectively for scFv-2G12, which were lower than scFv-5B5 (12.4-22.0 and 23.6-39.7 ng mL^-1). Results indicated the promising prospect of scFv-2G12 used for the detection of Cry1A toxins.

The role of teratogens in neural crest development

The neural crest (NC), discovered by Wilhelm His 150 years ago, gives rise to a multipotent migratory embryonic cell population that generates a remarkably diverse and important array of cell types during the development of the vertebrate embryo. These cells originate in the neural plate border (NPB), which is the ectoderm between the neural plate and the epidermis. They give rise to the neurons and glia of the peripheral nervous system, melanocytes, chondrocytes, smooth muscle cells, odontoblasts and neuroendocrine cells, among others. Neurocristopathies are a class of congenital diseases resulting from the abnormal induction, specification, migration, differentiation or death of NC cells (NCCs) during embryonic development and have an important medical and societal impact. In general, congenital defects affect an appreciable percentage of newborns worldwide. Some of these defects are caused by teratogens, which are agents that negatively impact the formation of tissues and organs during development. In this review, we will discuss the teratogens linked to the development of many birth defects, with a strong focus on those that specifically affect the development of the NC, thereby producing neurocristopathies. Although increasing attention is being paid to the effect of teratogens on embryonic development in general, there is a strong need to critically evaluate the specific role of these agents in NC development. Therefore, increased understanding of the role of these factors in NC development will contribute to the planning of strategies aimed at the prevention and treatment of human neurocristopathies, whose etiology was previously not considered.

Evaluation of apoptotic potential of glyphosate metabolites and impurities in human peripheral blood mononuclear cells (in vitro study)

Glyphosate is used for cereal, vegetable and fruit crops for reducing or inhibiting the growth of weeds as well as a desiccant for various grain crops. That is why, glyphosate has been shown to be accumulated in humans and animals through ingestion of food of both plant and animal origin. The study aimed to assessed the effect of glyphosate, its metabolites: aminomethylphosphonic acid (AMPA), methylphosphonic acid and its impurities: PMIDA, N-methylglyphosate, hydroxymethylphosphonic acid and bis(phosphonomethyl)amine on apoptosis induction in human peripheral blood mononuclear cells (PBMCs). PBMCs were exposed to the compounds studied at the concentrations ranging from 0.01 to 5 mM for 4 h. We have observed an increase in reactive oxygen species (including hydroxyl radical) and cytosolic calcium ions levels as well as reduction of transmembrane mitochondrial potential (ΔΨm) in PBMCs exposed to the compounds examined. All substances studied changed PBMCs membrane permeability, activated caspase-8, -9, -3 and caused chromatin condensation, which showed that they were capable of inducing apoptosis both via extrinsic and particularly intrinsic pathway. Generally the study demonstrated that there were no differences between apoptotic changes induced by glyphosate, its metabolites or impurities, and observed changes were provoked by high concentrations of investigated compounds.

Public health risks related to food safety issues in the food market: a systematic literature review

BACKGROUND

Food safety in the food market is one of the key areas of focus in public health, because it affects people of every age, race, gender, and income level around the world. The local and international food marketing continues to have significant impacts on food safety and health of the public. Food supply chains now cross multiple national borders which increase the internationalization of health risks. This systematic review of literature was, therefore, conducted to identify common public health risks related to food safety issues in the food market.

METHODS

All published and unpublished quantitative, qualitative, and mixed method studies were searched from electronic databases using a three step searching. Analytical framework was developed using the PICo (population, phenomena of interest, and context) method. The methodological quality of the included studies was assessed using mixed methods appraisal tool (MMAT) version 2018. The included full-text articles were qualitatively analyzed using emergent thematic analysis approach to identify key concepts and coded them into related non-mutually exclusive themes. We then synthesized each theme by comparing the discussion and conclusion of the included articles. Emergent themes were identified based on meticulous and systematic reading. Coding and interpreting the data were refined during analysis.

RESULTS

The analysis of 81 full-text articles resulted in seven common public health risks related with food safety in the food market. Microbial contamination of foods, chemical contamination of foods, food adulteration, misuse of food additives, mislabeling, genetically modified foods (GM foods), and outdated foods or foods past their use-by dates were the identified food safety-related public health risks in the food market.

CONCLUSION

This systematic literature review identified common food safety-related public health risks in the food market. The results imply that the local and international food marketing continues to have significant impacts on health of the public. The food market increases internationalization of health risks as the food supply chains cross multiple national borders. Therefore, effective national risk-based food control systems are essential to protect the health and safety of the public. Countries need also assure the safety and quality of their foods entering international trade and ensure that imported foods conform to national requirements.

High Incidence of Moderately Reduced Renal Function and Lead Bioaccumulation in Agricultural Workers in Assin South District, Ghana: A Community-Based Case-Control Study

Background

The quest to enhance agricultural productivity and crop yields has led to increased use of agrochemicals on a global scale. Long-term use of these agrochemicals may be associated with adverse health implications.

Objective

To assess haematological indices, renal function, heavy metal bioaccumulation in farmers and sprayers, and their use of personal protective equipment (PPE).

Materials and Methods

This community-based case-control study was conducted from January 2018 to June 2018 in the Assin South District, Central Region, Ghana. A total of 144 participants were conveniently sampled: 83 agricultural workers (cases) and 61 indigenes with no direct exposure to agrochemicals (controls). Structured questionnaire was used to obtain demographic data as well as agricultural work practices followed by cases. Venous blood samples were drawn from participants and used for estimating full blood count and renal function (serum creatinine (CRE), blood-urea nitrogen (BUN), BUN : CRE ratio, and estimated GFR (eGFR)). Serum lead, arsenic, and cadmium levels were estimated using the Varian AA 240FS atomic spectrometer in an acetylene-air flame.

Results

The median RBC (4.49 vs. 4.92 × 10¹²/L), haemoglobin (12.50 vs. 13.70 g/dL), and platelet (220.00 vs. 268.00) counts were significantly lower in cases. A significantly higher proportion of cases were classified as anaemic or having microcytic cells compared to controls. Also, serum urea (4.08 vs. 3.41; p=0.0009), creatinine (108.10 vs. 101.10; p=0.0286), and BUN : CRE ratio (19.75 vs. 17.84) were significantly higher in cases. Additionally, 18.1% of cases were classified as having moderately reduced renal function compared to only 6.6% of controls. Moreover, a significantly higher proportion of cases had detectable serum lead (55.6% vs. 16.4%) and arsenic (53.1% vs. 9.8%) levels compared to controls. However, on average, 80% of agricultural workers did not use personal protective equipment (PPE) when applying agrochemicals; 84.3% of used agrochemical containments were discarded near the river/canal.

Conclusion

Neglect of the use of PPE may be predisposing the agrochemical workers and community to lead and arsenic bioaccumulation with a consequent reduced haematological and renal function.

Maternal glyphosate-based herbicide exposure alters antioxidant-related genes in the brain and serum metabolites of male rat offspring

In response to the rapid development of genetically engineered glyphosate-tolerant crops, the use of glyphosate-based herbicides (GBHs), in agriculture, has increased substantially. Currently, it is estimated that 747 million kg of GBHs are applied per year. Although several epidemiological studies have demonstrated that there are health risks associated with GBH exposure, the effects these chemicals have on the oxidative and inflammatory response in the brain are still unclear. In fact, alterations in these processes could contribute to the development of neurological diseases, such as Alzheimer's disease and autism spectrum disorders. The present study exposed pregnant rats to GBH and evaluated changes in the expression of genes related to oxidnte defense and inflammation response and monitored the serum metabolome in the adult male offspring. Pregnant Wistar rats were administered distilled water or Roundup®, at either 5 and 50 mg/kg/day, (p.o.) from gestational day (GD) 18 to postnatal day (PND) 5. There was a significant increase in the gene expression levels of Neuroglobin (Ngb - oxygen storage and tissue protection) (105%, p = 0.031), Glutathione Peroxidase 1 (Gpx1 - oxidative stress) (95%, p = 0.005), Prostaglandin-Endoperoxidase Synthase 1 (Ptgs1 - inflammation) (109%, p = 0.033) and Hypoxia inducible factor 1 subunit alpha (Hif1α - oxygen sensor) (73%, p = 0.017), in the cerebellum of PND90 rats perinatally exposed to 50 mg GBH/kg/day. Moreover, both GBH-exposed groups displayed a significant decrease in the expression of Catalase (Cat - oxidative stress) (49%, p = 0.003; and 31% p = 0.050, respectively) expression, in the cortex. Serum metabolites analyses, from the same animals of each group, demonstrated that there were significant changes in the concentrations of lysophosphatidylcholine and phosphatidylcholine, which have been associated with neurodegenerative diseases. The results of the present study suggest GBH exposure during pregnancy alters the expression of genes associated with oxidant defense, inflammation and lipid metabolism. It is plausible that maternal GBH exposure could have lasting neuronal effects on the offspring later in life.

The evidence of human exposure to glyphosate: a review

BACKGROUND

Despite the growing and widespread use of glyphosate, a broad-spectrum herbicide and desiccant, very few studies have evaluated the extent and amount of human exposure.

OBJECTIVE

We review documented levels of human exposure among workers in occupational settings and the general population.

METHODS

We conducted a review of scientific publications on glyphosate levels in humans; 19 studies were identified, of which five investigated occupational exposure to glyphosate, 11 documented the exposure in general populations, and three reported on both.

RESULTS

Eight studies reported urinary levels in 423 occupationally and para-occupationally exposed subjects; 14 studies reported glyphosate levels in various biofluids on 3298 subjects from the general population. Average urinary levels in occupationally exposed subjects varied from 0.26 to 73.5 μg/L; environmental exposure urinary levels ranged from 0.16 to 7.6 μg/L. Only two studies measured temporal trends in exposure, both of which show increasing proportions of individuals with detectable levels of glyphosate in their urine over time.

CONCLUSIONS

The current review highlights the paucity of data on glyphosate levels among individuals exposed occupationally, para-occupationally, or environmentally to the herbicide. As such, it is challenging to fully understand the extent of exposure overall and in vulnerable populations such as children. We recommend further work to evaluate exposure across populations and geographic regions, apportion the exposure sources (e.g., occupational, household use, food residues), and understand temporal trends.

In vitro evaluation of genomic damage induced by glyphosate on human lymphocytes

Glyphosate is an important broad-spectrum herbicide used in agriculture and residential areas for weed and vegetation control, respectively. In our study, we analyzed the in vitro clastogenic and/or aneugenic effects of glyphosate by chromosomal aberrations and micronuclei assays. Human lymphocytes were exposed to five glyphosate concentrations: 0.500, 0.100, 0.050, 0.025, and 0.0125 μg/mL, where 0.500 μg/mL represents the established acceptable daily intake value, and the other concentrations were tested in order to establish the genotoxicity threshold for this compound. We observed that chromosomal aberration (CA) and micronuclei (MNi) frequencies significantly increased at all tested concentrations, with exception of 0.0125 μg/mL. Vice versa, no effect has been observed on the frequencies of nuclear buds and nucleoplasmic bridges, with the only exception of 0.500 μg/mL of glyphosate that was found to increase in a significant manner the frequency of nucleoplasmic bridges. Finally, the cytokinesis-block proliferation index and the mitotic index were not significantly reduced, indicating that glyphosate does not produce effects on the proliferation/mitotic index at the tested concentrations.

The mechanism of DNA damage induced by Roundup 360 PLUS, glyphosate and AMPA in human peripheral blood mononuclear cells - genotoxic risk assessement

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 1000 μM on DNA damage in human peripheral blood mononuclear cells (PBMCs). The cells were incubated for 24 h. 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 5 μM, while glyphosate and particularly AMPA induced DNA lesions from the concentration of 250 μM and 500 μM, 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.

Formulants of glyphosate-based herbicides have more deleterious impact than glyphosate on TM4 Sertoli cells

Roundup and Glyphogan are glyphosate-based herbicides containing the same concentration of glyphosate and confidential formulants. Formulants are declared as inert diluents but some are more toxic than glyphosate, such as the family of polyethoxylated alkylamines (POEA). We tested glyphosate alone, glyphosate-based herbicide formulations and POEA on the immature mouse Sertoli cell line (TM4), at concentrations ranging from environmental to agricultural-use levels. Our results show that formulations of glyphosate-based herbicides induce TM4 mitochondrial dysfunction (like glyphosate, but to a lesser extent), disruption of cell detoxification systems, lipid droplet accumulation and mortality at sub-agricultural doses. Formulants, especially those present in Glyphogan, are more deleterious than glyphosate and thus should be considered as active principles of these pesticides. Lipid droplet accumulation after acute exposure to POEA suggests the rapid penetration and accumulation of formulants, leading to mortality after 24 h. As Sertoli cells are essential for testicular development and normal onset of spermatogenesis, disturbance of their function by glyphosate-based herbicides could contribute to disruption of reproductive function demonstrated in mammals exposed to these pesticides at a prepubertal stage of development.

Oxidative stress, cholinesterase activity, and DNA damage in the liver, whole blood, and plasma of Wistar rats following a 28-day exposure to glyphosate

In this 28 day-study, we evaluated the effects of herbicide glyphosate administered by gavage to Wistar rats at daily doses equivalent to 0.1 of the acceptable operator exposure level (AOEL), 0.5 of the consumer acceptable daily intake (ADI), 1.75 (corresponding to the chronic population-adjusted dose, cPAD), and 10 mg kg-1 body weight (bw) (corresponding to 100 times the AOEL). At the end of each treatment, the body and liver weights were measured and compared with their baseline values. DNA damage in leukocytes and liver tissue was estimated with the alkaline comet assay. Oxidative stress was evaluated using a battery of endpoints to establish lipid peroxidation via thiobarbituric reactive substances (TBARS) level, level of reactive oxygen species (ROS), glutathione (GSH) level, and the activity of glutathione peroxidase (GSH-Px). Total cholinesterase activity and the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were also measured. The exposed animals gained less weight than control. Treatment resulted in significantly higher primary DNA damage in the liver cells and leukocytes. Glyphosate exposure significantly lowered TBARS in the liver of the AOEL, ADI, and cPAD groups, and in plasma in the AOEL and cPAD group. AChE was inhibited with all treatments, but the AOEL and ADI groups significantly differed from control. Total ChE and plasma/liver ROS/GSH levels did not significantly differ from control, except for the 35 % decrease in ChE in the AOEL and ADI groups and a significant drop in liver GSH in the cPAD and 100xAOEL groups. AOEL and ADI blood GSH-Px activity dropped significantly, but in the liver it significantly increased in the ADI, cPAD, and 100xAOEL groups vs. control. All these findings show that even exposure to low glyphosate levels can have serious adverse effects and points to a need to change the approach to risk assessment of low-level chronic/sub-chronic glyphosate exposure, where oxidative stress is not necessarily related to the genetic damage and AChE inhibition.

The distinct properties of natural and GM cry insecticidal proteins

The Cry toxins are a family of crystal-forming proteins produced by the bacterium Bacillus thuringiensis. Their mode of action is thought to be to create pores that disrupt the gut epithelial membranes of juvenile insects. These pores allow pathogen entry into the hemocoel, thereby killing the insect. Genes encoding a spectrum of Cry toxins, including Cry mutants, Cry chimaeras and other Cry derivatives, are used commercially to enhance insect resistance in genetically modified (GM) crops. In most countries of the world, such GM crops are regulated and must be assessed for human and environmental safety. However, such risk assessments often do not test the GM crop or its tissues directly. Instead, assessments rely primarily on historical information from naturally occurring Cry proteins and on data collected on Cry proteins (called 'surrogates') purified from laboratory strains of bacteria engineered to express Cry protein. However, neither surrogates nor naturally occurring Cry proteins are identical to the proteins to which humans or other nontarget organisms are exposed by the production and consumption of GM plants. To-date there has been no systematic survey of these differences. This review fills this knowledge gap with respect to the most commonly grown GM Cry-containing crops approved for international use. Having described the specific differences between natural, surrogate and GM Cry proteins this review assesses these differences for their potential to undermine the reliability of risk assessments. Lastly, we make specific recommendations for improving risk assessments.