Glyphosate, AMPA and glufosinate in soils and earthworms in a French arable landscape

Glyphosate-based herbicides reduced overwintering population and reproduction of agrobiont spiders

Spiders are important in ecosystem and serve as predators in the biological control of pest insects in agroecosystem, where they encounter various harsh challenges including pesticides and low temperature in winter. Glyphosate-based herbicides (GBH) are widely and frequently applied to diminish weeds, exposing spiders a disturbed habitat, especially to overwintering spiders. We conducted a study combining field surveys and lab assays, to assess the effects of a GBH on the overwintering of the agrobiont wolf spider, Pardosa pseudoannulata. The GBH significantly reduced the overall overwintering spider population by about 69 %, and reduced the number of vulnerable juveniles by about 80 %. The survivors exhibited substantial fitness costs such as reproductive dysfunctions and enhanced oxidative stress responses. We then mimicked the overwinter process in lab. We housed spiders on soil patches with and without weeds to examine whether weeds contributed to the GBH's sublethal effects. Spiders overwintered independent of weeds when GBH was not applied. When GBH was applied before or during overwintering, juvenile spiders overwintered in weedy habitats exhibited reduced survival and fecundity, and increased oxidative stress compared to their counterparts in weed-free habitats. Therefore, GBH-containing weeds contributed to the persistent adverse effects of GBH on overwintering spiders. The findings revealed the cross-talk among weeds, herbicides, low temperature, and non-target organisms. The study provides novel information on the environmental risk assessment of pesticides and rational scheduling of pesticide application.

How do glyphosate and AMPA alter the microbial community structure and phosphorus cycle in rice-crayfish systems?

Glyphosate, a commonly used organophosphorus herbicide in rice-crayfish cropping regions, may alter regional phosphorus cycle processes while affecting the structure of microbial communities. However, the effects of glyphosate residues on rice-crayfish systems remain unclear. In this study, we assessed the spatial and temporal distribution characteristics of glyphosate and its primary degradation products, as well as the impact mechanisms of glyphosate on microbial communities and the phosphorus cycle in rice-crayfish systems such as paddy fields, breeding ditches and recharge rivers. The detection rates of glyphosate and aminomethylphosphonic acid (AMPA) were 100% in rice-crayfish systems. Concentrations of glyphosate in the water phase and soil/sediment were as high as 0.012 μg/L and 7.480 μg/kg, respectively, and concentrations of AMPA were as high as 17.435 μg/L and 13.200 μg/kg, respectively. Glyphosate concentrations were not affected by rainfall or sampling site, but concentrations of AMPA in the water phase of recharge rivers were affected by rainfall. The glyphosate concentration was significantly and positively correlated with RBG-16-58-14 abundance, and the AMPA concentration was significantly and positively correlated with Actinobacteria and Lysobacter abundance, and negatively correlated with Cyanobacteria abundance (P < 0.05). The highest abundances of phoD, phnK, and ppx genes were found in all soils/sediments. Glyphosate concentration in soil/sediment was significantly and positively correlated with the abundance of phoD gene encoding an organophosphorus-degrading enzyme and ppx gene encoding poly inorganic phosphate (Pi) hydrolase (P < 0.05). In addition, the glyphosate concentration was significantly and positively correlated with the Ca-bonded Pi content (P < 0.05). This implies that glyphosate may promote the production of stable Pi in rice-crayfish systems by increasing the abundance of phoD and ppx genes. The results of this study reveal the impact mechanism of glyphosate on the phosphorus cycle in rice-crayfish systems and provide a basis for the risk assessment of glyphosate.

Role of trophic interactions in transfer and cascading impacts of plant protection products on biodiversity: a literature review

Plant protection products (PPPs) have historically been one of the classes of chemical compounds at the frontline of raising scientific and public awareness of the global nature of environmental pollution and the role of trophic interactions in shaping the impacts of chemicals on ecosystems. Despite increasingly strong regulatory measures since the 1970s designed to avoid unintentional effects of PPPs, their use is now recognised as a driver of biodiversity erosion. The French Ministries for the Environment, Agriculture and Research commissioned a collective scientific assessment to synthesise the current science and knowledge on the impacts of PPPs on biodiversity and ecosystem services. Here we report a literature review of the state of knowledge on the propagation of PPP residues and the effects of PPPs in food webs, including biopesticides, with a focus on current-use PPPs. Currently used PPPs may be stronger drivers of the current biodiversity loss than the banned compounds no longer in use, and there have been far fewer reviews on current-use PPPs than legacy PPPs. We first provide a detailed overview of the transfer and propagation of effects of PPPs through trophic interactions in both terrestrial and aquatic ecosystems. We then review cross-ecosystem trophic paths of PPP propagation, and provide insight on the role of trophic interactions in the impacts of PPPs on ecological functions. We conclude with a summary of the available knowledge and the perspectives for tackling the main gaps, and address areas that warrant further research and pathways to advancing environmental risk assessment.

Characterizing environmental contamination by plant protection products along the land-to-sea continuum:a focus on France and French overseas territories

Environmental compartments are contaminated by a broad spectrum of plant protection products (PPPs) that are currently widely used in agriculture or, for some of them, whose use was banned many years ago. The aim of this study is to draw up an overview of the levels of contamination of soils, continental aquatic environments, seawaters and atmosphere by organic PPPs in France and the French overseas territories, based on data from the scientific publications and the grey literature. It is difficult to establish an exhaustive picture of the overall contamination of the environment because the various compartments monitored, the monitoring frequencies, the duration of the studies and the lists of substances are not the same. Of the 33 PPPs most often recorded at high concentration levels in at least one compartment, 5 are insecticides, 9 are fungicides, 15 are herbicides and 4 are transformation products. The PPP contamination of the environment shows generally a seasonal variation according to crop cycles. On a pluriannual scale, the contamination trends are linked to the level of use driven by the pest pressure, and especially to the ban of PPP. Overall, the quality of the data acquired has been improved thanks to new, more integrative sampling strategies and broad-spectrum analysis methods that make it possible to incorporate the search for emerging contaminants such as PPP transformation products. Taking into account additional information (such as the quantities applied, agricultural practices, meteorological conditions, the properties of PPPs and environmental conditions) combined with modelling tools will make it possible to better assess and understand the fate and transport of PPPs in the environment, inter-compartment transfers and to identify their potential impacts. Simultaneous monitoring of all environmental compartments as well as biota in selected and limited relevant areas would also help in this assessment.

Pesticide residues in boreal arable soils: Countrywide study of occurrence and risks

Large volumes of pesticides are applied every year to support agricultural production. The intensive use of pesticides affects soil quality and health, but soil surveys on pesticide residues are scarce, especially for northern Europe. We investigated the occurrence of 198 pesticide residues, including both banned and currently used substances in 148 field sites in Finland. Results highlight that pesticide residues are common in the agricultural soils of Finland. A least one residue was found in 82% of the soils, and of those 32% contained five or more residues. Maximum total residue concentration among the conventionally farmed soils was 3043 μg/kg, of which AMPA and glyphosate contributed the most. Pesticide residues were also found from organically farmed soils, although at 75-90% lower concentrations than in the conventionally farmed fields. Thus, despite the application rates of pesticides in Finland being generally much lower than in most parts of central and southern Europe, the total residue concentrations in the soils occurred at similar or at higher levels. We also established that AMPA and glyphosate residues in soil are significantly higher in fields with cereal dominated rotations than in grass dominated or cereal-grass rotations. However, risk analyses for individual substances indicated low ecological risk for most of the fields. Furthermore, the total ecological risk associated with the mixtures of residues was mostly low except for 21% of cereal dominated fields with medium risk. The results showed that the presence of mixtures of pesticide residues in soils is a rule rather than an exception also in boreal soils. In highly chemicalized modern agriculture, the follow-up of the residues of currently used pesticides in national and international soil monitoring programs is imperative to maintain soil quality and support sustainable environment policies.

Effects of glyphosate on earthworms: From fears to facts

Glyphosate is the most widely applied herbicide worldwide, contaminating water, soils, and living organisms. Earthworms are emblematic soil organisms used as indicators of soil quality, but knowledge about the impacts of glyphosate and glyphosate-based herbicides (GBH) on these key soil organisms is scattered. Here, we examine this knowledge in detail to answer four questions: (1) Which endpoint is the most sensitive when assessing the effects of glyphosate or GBH in earthworms? (2) Which is most toxic to earthworms: glyphosate or GBH? (3) Are glyphosate and GBH harmful to earthworms when used at the recommended application dose? (4) What are the interactions between glyphosate or GBH and other chemicals in earthworms? The results indicate that a weak legislation led to improper assessment of the ecotoxicity of glyphosate during the last renewal in 2017. Our findings also highlighted that negative effects can occur in earthworms at the recommended application rate, although not after only a single application or when considering only the mortality of adult individuals. However, under more realistic conditions, that is, when assessing sensitive endpoints (e.g., reproduction, growth) and using species present in the field, after several applications per year, the negative effects of glyphosate or GBH on earthworms were observed at the subindividual, individual, population, and community levels, as well as on earthworm-mediated functions. Our recommendations are as follows: (i) competent agencies should collect more information on the toxicity of these compounds to earthworms before the next renewal deadline, with emphasis on the use of the updated legislation on the topic, and (ii) scientists should increase research on the effects of these herbicides on soil invertebrate species, with emphasis on earthworms, using guideline tests and obtain data from long-term field testing. Integr Environ Assess Manag 2024;20:1330-1336. © 2023 SETAC.

Glyphosate presence in human sperm: First report and positive correlation with oxidative stress in an infertile French population

Environmental exposure to endocrine disruptors, such as pesticides, could contribute to a decline of human fertility. Glyphosate (GLY) is the main component of Glyphosate Based Herbicides (GBHs), which are the most commonly herbicides used in the world. Various animal model studies demonstrated its reprotoxicity. In Europe, GLY authorization in agriculture has been extended until 2034. Meanwhile the toxicity of GLY in humans is still in debate. The aims of our study were firstly to analyse the concentration of GLY and its main metabolite, amino-methyl-phosphonic acid (AMPA) by LC/MS-MS in the seminal and blood plasma in an infertile French men population (n=128). We secondly determined Total Antioxidant Status (TAS) and Total Oxidant Status (TOS) using commercial colorimetric kits and some oxidative stress biomarkers including malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) by ELISA assays. We next analysed potential correlations between GLY and oxidative stress biomarkers concentration and sperm parameters (sperm concentration, progressive speed, anormal forms). Here, we detected for the first time GLY in the human seminal plasma in significant proportions and we showed that its concentration was four times higher than those observed in blood plasma. At the opposite, AMPA was undetectable. We also observed a strong positive correlation between plasma blood GLY concentrations and plasma seminal GLY and 8-OHdG concentrations, the latter reflecting DNA impact. In addition, TOS, Oxidative Stress Index (OSI) (TOS/TAS), MDA blood and seminal plasma concentrations were significantly higher in men with glyphosate in blood and seminal plasma, respectively. Taken together, our results suggest a negative impact of GLY on the human reproductive health and possibly on his progeny. A precaution principle should be applied at the time of the actual discussion of GLY and GBHs formulants uses in Europe by the authorities.

Cellular and Genomic Instability Induced by the Herbicide Glufosinate-Ammonium: An In Vitro and In Vivo Approach

Glufosinate-ammonium (GLA), an organophosphate herbicide, is released at high concentrations in the environment, leading to concerns over its potential genotoxic effects. However, few articles are available in the literature reporting the possible cellular and nuclear effects of this compound. We assessed, by in vitro and in vivo micronucleus assays, the genotoxicity of GLA on cultured human lymphocytes and Lymnaea stagnalis hemocytes at six concentrations: 0.010 (the established acceptable daily intake value), 0.020, 0.050, 0.100, 0.200, and 0.500 µg/mL. In human lymphocytes, our results reveal a significant and concentration-dependent increase in micronuclei frequency at concentrations from 0.100 to 0.500 μg/mL, while in L. stagnalis hemocytes, significant differences were found at 0.200 and 0.500 μg/mL. A significant reduction in the proliferation index was observed at all tested concentrations, with the only exception of 0.010 μg/mL, indicating that the exposure to GLA could lead to increased cytotoxic effects. In L. stagnalis, a significant reduction in laid eggs and body growth was also observed at all concentrations. In conclusion, we provided evidence of the genomic and cellular damage induced by GLA on both cultured human lymphocytes and a model organism's hemocytes; in addition, we also demonstrated its effects on cell proliferation and reproductive health in L. stagnalis.

Recent technologies for glyphosate removal from aqueous environment: A critical review

The growing demand for food has led to an increase in the use of herbicides and pesticides over the years. One of the most widely used herbicides is glyphosate (GLY). It has been used extensively since 1974 for weed control and is currently classified by the World Health Organization (WHO) as a Group 2A substance, probably carcinogenic to humans. The industry and academia have some disagreements regarding GLY toxicity in humans and its effects on the environment. Even though this herbicide is not mentioned in the WHO water guidelines, some countries have decided to set maximum acceptable concentrations in tap water, while others have decided to ban its use in crop production completely. Researchers around the world have employed different technologies to remove or degrade GLY, mostly at the laboratory scale. Water treatment plants combine different technologies to remove it alongside other water pollutants, in some cases achieving acceptable removal efficiencies. Certainly, there are many challenges in upscaling purification technologies due to the costs and lack of factual information about their adverse effects. This review presents different technologies that have been used to remove GLY from water since 2012 to date, its detection and removal methods, challenges, and future perspectives.

Synthesis and application of a dual-functional fluorescent probe for sequential recognition of Zn2+and glyphosate

A novel fluorescent probe QL was designed and synthesized based on Schiff base by 2-hydrazinobenzothiazole to sequentially recognize Zn2+ and glyphosate. The probe QL was capable to detect Zn2+ in DMSO solution via fluorescence enhancement, and exhibited good selectivity and anti-interference ability. The combination mode was 1:2 between probe QL and Zn2+ according to the method of job's plot, and the detection limit of probe QL for Zn2+ was found to be 4.51 × 10-8 M, which exhibited excellent sensitivity. Furthermore, the system QL-Zn2+ could detect glyphosate by causing fluorescence quenching response and with a color change from yellow to colorless for naked-eye detection. The detection limit for glyphosate was found to be 4.93 × 10-8 M, which was far below the Standards for Drinking Water Quality (GB5749-2006) acceptable limits (0.7 μg/mL for glyphosate). Notably, the probe QL and its complex QL-Zn2+ have been successfully applied to detect Zn2+ and glyphosate in water, respectively.

Construction of CuO/Fe2O3 Nanozymes for Intelligent Detection of Glufosinate and Chlortetracycline Hydrochloride

In this work, CuO/Fe2O3 nanozymes with high peroxidase-like activity were synthesized by using hydrothermal and calcination methods. The high-resolution transmission electron microscopy (HRTEM) proved that the heterogeneous interface of CuO/Fe2O3 was the main reason for the high enzyme-like activity. Strong interactions of CuO and Fe2O3 were successfully verified by X-ray absorption near-edge structure (XANES) characterization. Experiments and density functional theory (DFT) calculations were also used to explain the increased enzyme activity. The heterogeneous interface acted as the main active center, facilitating the electron transfer from CuO to Fe2O3. A colorimetric and intelligent sensing system was constructed based on deep learning. Using the peroxidase-like activity of CuO/Fe2O3, a platform for glufosinate pesticides and chlortetracycline hydrochloride (CTC) with the signal "on-off-on" changes were established. The limit of detection (LOD) of glufosinate and CTC was 28 and 0.69 μM, respectively. It was successfully applied in the detection of environmental water and soil. This study can provide an intelligent detection method for environmental monitoring.

Sub-acute toxicity of the herbicide glufosinate-ammonium exposure in adult red swamp crayfish (Procambarus clarkii)

Glufosinateammonium (GLA) is one of the most widely used agricultural herbicides. It is frequently detected in surface waters near farmland and may pose a risk to non-target aquatic species. This study aimed to explore the toxicity of subacute GLA exposure in crayfish. Adult red swamp crayfish were exposed to GLA (0, 1, 10, and 100 mg/L) for 21 days. Bioaccumulation, oxidative stress, nonspecific immunity, and the expression of genes encoding xenobiotic detoxification-related enzymes were examined. The results showed GLA accumulation and hepatopancreatic histopathological changes (dilation of hepatic tubules and vacuolation of hepatocytes) in the exposed crayfish. GLA exposure induced ROS production, inhibited glutathione expression, and catalase activity in the crayfish hepatopancreas, as well as inhibited immunoenzyme expression (acid phosphatase, alkaline phosphatase, and lysozyme) in the hemolymph. In addition, the total hemocyte number decreased, and the proportion of hemocyte subsets changed significantly. Superoxide dismutase first increased and then decreased with increasing GLA dosage. GLA promoted the expression of biotransformation enzymes (cypb5, gst) in the hepatopancreas. Our results suggest that subacute GLA exposure caused structural damage to the hepatopancreatic tissue and decreased antioxidant capacity and non-specific immunity in crayfish. These findings provide insight into the toxicity of herbicides on non-target organisms.

Glyphosate-based herbicide (GBH) challenged thermoregulation in lizards (Eremias argus), compensatory warming could mitigate this effect

Chemical pollution and global warming are two major threats to reptiles, and these two factors can interact with each other. Glyphosate have attracted worldwide attention due to their ubiquitous occurrence, yet their impact on reptiles remains unknown. We designed a crossover experiment with different external GBH exposures (control/GBH) x different environmental temperatures (current climate treatment/warmer climate treatment) over 60 days to simulate environmental exposure in the Mongolian Racerunner lizard (Eremias argus). Preferred body temperature and active body temperature data were collected to calculate the accuracy of thermoregulation, while liver detoxification metabolic enzymes, oxidative stress system function, and the non-targeted metabolome of the brain tissue were assessed. Warmer-treated lizards adjusted their physiological levels and behavioral strategies in response to increased ambient temperatures and maintained body temperature homeostasis at moderate thermal perturbations. GBH-treated lizards suffered from oxidative damage to the brain tissue and abnormal histidine metabolism, thus their thermoregulatory accuracy reduced. Interestingly, at elevated ambient temperatures, GBH treatment did not affect on their thermoregulatory, possibly through several temperature-dependent detoxification mechanisms. Importantly, this data suggested that the subtle toxicological effects of GBH may threaten increasingly thermoregulation behavior of E. argus with species-wide repercussions, as climate change and exposure time extension.

Including the bioconcentration of pesticide metabolites in plant uptake modeling

Although several models of pesticide uptake into plants are available, there are few modeling studies on the bioconcentration of metabolites in plants. Ignoring metabolites in plant uptake models can result in an underestimation of the parent compound's overall impacts on human health associated with pesticide residues in harvested food crops. To address this limitation, we offer a metabolite-based plant uptake model to predict the bioconcentration of the parent compound and its metabolites in plants. We used the uptake of glyphosate and its major metabolite (aminomethylphosphonic acid, AMPA) into potato as an example. The analysis of variability revealed that soil properties (affecting the soil sorption coefficient), dissipation half-life in soil, and metabolic half-life in the potato had a significant impact on the simulated AMPA concentration in the potato, indicating that regional variability could be generated in the plant bioconcentration process of metabolites. The proposed model was further compared using the non-metabolite model. The findings of the comparison suggested that the non-metabolite model, which is integrated with the AMPA bioconcentration process, can predict the AMPA concentration in the potato similarly to the proposed model. In conclusion, we provide insight into the bioconcentration process of metabolites in tuber plants from a modeling viewpoint, with some crucial model inputs, such as biotransformation and metabolic rate constants, requiring confirmation in future studies. The modeling demonstration emphasizes that it is relevant to consider bioaccumulation of metabolites, which can propagate further into increased overall residues of harmful compounds, especially in cases where metabolites have higher toxicity effect potency than their respective parent compounds.

Hotspots of soil pollution: Possible glyphosate and aminomethylphosphonic acid risks on terrestrial ecosystems and human health

The study presents a literature review of glyphosate (GLY) occurrence and its breakdown product, aminomethylphosphonic acid (AMPA), in soils worldwide, but with a specific focus on South America. In addition, an ecological risk approach based on the ecotoxicological endpoints for key soil biota (e.g., collembolans, and earthworms) assessed the impact of GLY and AMPA on these organisms. A generic probabilistic model for human health risk was also calculated for the different world regions. For what reports the risk for edaphic species and the level of pollution under the worst-case scenario, the South American continent was identified as the region of most concern. Nonetheless, other areas may also be in danger, but no risk could be calculated due to the lack of data. Since tropical countries are the top food exporters worldwide, the results obtained in this study must be carefully examined for their implications on a global scale. Some of the factors behind the high levels of these two chemicals in soils are debated (e.g., permissive protection policies, the extensive use of genetically modified crops), and some possible guidelines are presented that include, for example, further environmental characterisation and management of pesticide residues. The present review integrates data that can be used as a base by policymakers and decision-makers to develop and implement environmental policies.

The diabetogenic effects of pesticides: Evidence based on epidemiological and toxicological studies

While the use of pesticides has improved grain productivity and controlled vector-borne diseases, the widespread use of pesticides has resulted in ubiquitous environmental residues that pose health risks to humans. A number of studies have linked pesticide exposure to diabetes and glucose dyshomeostasis. This article reviews the occurrence of pesticides in the environment and human exposure, the associations between pesticide exposures and diabetes based on epidemiological investigations, as well as the diabetogenic effects of pesticides based on the data from in vivo and in vitro studies. The potential mechanisms by which pesticides disrupt glucose homeostasis include induction of lipotoxicity, oxidative stress, inflammation, acetylcholine accumulation, and gut microbiota dysbiosis. The gaps between laboratory toxicology research and epidemiological studies lead to an urgent research need on the diabetogenic effects of herbicides and current-use insecticides, low-dose pesticide exposure research, the diabetogenic effects of pesticides in children, and assessment of toxicity and risks of combined exposure to multiple pesticides with other chemicals.

Pesticide Residues in French Soils: Occurrence, Risks, and Persistence

Contamination of the environment by pesticide residues is a growing concern given their widespread presence in the environment and their effects on ecosystems. Only a few studies have addressed the occurrence of pesticides in soils, and their results highlighted the need for further research on the persistence and risks induced by those substances. We monitored 111 pesticide residues (48 fungicides, 36 herbicides, 25 insecticides and/or acaricides, and two safeners) in 47 soils sampled across France under various land uses (arable lands, vineyards, orchards, forests, grasslands, and brownfields). Pesticides were found in 98% of the sites (46 of the 47 sampled), including untreated areas such as organic fields, forests, grasslands, and brownfields, with up to 33 different substances detected in one sample, mostly fungicides and herbicides. The concentrations of herbicides were the highest in soils with glyphosate, and its transformation product, AMPA, contributed 70% of the cumulative herbicides. Risk assessment underlined a moderate to high risk for earthworms in arable soils mostly attributed to insecticides and/or acaricides. Finally, the comparison with pesticide application by farmers underlines the presence of some residues long after their supposed 90% degradation and at concentrations higher than predicted environmental concentrations, leading to questions their real persistence in soils.

Integrated metabolomics and transcriptomics reveal glyphosate based-herbicide induced reproductive toxicity through disturbing energy and nucleotide metabolism in mice testes

Glyphosate is a widely used herbicide that has deleterious effects on animal reproduction. However, details regarding the systematic mechanisms of glyphosate-induced reproductive toxicity are limited. This study aimed to investigate the toxic effects of glyphosate-based herbicide (GBH) on reproduction in mice exposed to 0 (control group), 50 (low-dose group), 250 (middle-dose group), and 500 (high-dose group) mg/kg/day GBH for 30 days. Toxicological parameters, metabolomics, and transcriptomics were performed to reveal GBH-induced reproductive toxicity. Our findings demonstrated that GBH exposure damaged mitochondrial pyknosis and the nuclear membrane of spermatogonia. GBH triggered a significant increase in sperm malformations in the high-dose group. Omics data showed that GBH impaired the Krebs cycle and respiratory chain, blocked pyruvate metabolism and glycolysis/gluconeogenesis, and influenced the pentose phosphate pathway and nucleotide synthesis and metabolism. Overall, the multi-omics results revealed systematic and comprehensive evidence of the adverse effects of GBH exposure, providing new insights into the reproductive toxicity of organophosphorus pesticides.

Neonicotinoids: Still present in farmland birds despite their ban

Neonicotinoids (neonics) are the most widely used insecticides worldwide and are considered to be of low risk to non-target organisms such as vertebrates. Further, they are reported to be rapidly excreted and metabolized, reducing their potential toxicity. Nevertheless, growing evidence of adverse effects of neonics on farmland bird species raise questions about the purported harmless nature of these pesticides. We attempted to search for pesticide residues in species of different trophic levels and at different life stages, by using multiple bird monitoring programs on a Long-Term Socio-Ecological Research (LTSER) platform. Three passerine birds-the blackbird (Turdus merula), cirl bunting (Emberiza cirlus), and common nightingale (Luscinia megarhynchos)-that feed on seeds and invertebrates were monitored during their reproductive period, and the grey partridge (Perdix perdix) that feeds on seeds was monitored during its wintering period. We also monitored chicks of an apex predator-the Montagu's harrier (Circus pygargus)-that preys mostly upon common voles but also upon insects. We found that the birds' blood samples showed presence of residues of five neonics: three banned since 2018 in France-clothianidin, thiacloprid, and thiamethoxam-and two-dinotefuran and nitenpyram-used for veterinary purposes only. While none of these neonics was detected in blackbirds, all were present in grey partridges. Clothianidin was detected in all species, except blackbirds. Concentrations of the three banned neonics were similar or higher than concentrations found in birds monitored elsewhere before the ban. These findings raise questions about the persistence of neonics within the environment and the mode of exposure to wild fauna. Future investigations on the sublethal effects of these neonics on life-history traits of these farmland birds may help in providing a better understanding of the effects of exposure of bird populations to these insecticides, and also to the consequent effect on human health.

Comparison of the chronic and multigenerational toxicity of racemic glufosinate and l-glufosinate to Caenorhabditis elegans at environmental concentrations

Glufosinate-ammonium, the second largest transgene crop resistant herbicide, is classified as a mobile persistent pollutant by the U.S. Environmental Protection Agencybecause of its slow decomposition and easy mobile transfer in a water environment. The chronic and multigeneration toxicity of this compound to environmental organisms are alarming. In this study, racemic glufosinate-ammonium and the effective isomer, l-glufosinate-ammonium, were used as the test agents. The developmental, neurotoxic and reproductive toxicities of Caenorhabditis elegans to their parents and progeny were studied by continuous exposure in water at concentrations of 0.1, 1, 10 and 100 μg/L. The causes of toxicity differences were analysed from oxidative stress and transcription levels. Through oxidative stress of C. elegans, racemic glufosinate-ammonium and l-glufosinate-ammonium both mediated the developmental toxicity (shortened developmental cycle, reduced body length and width, promoted ageingand decreased longevity), neurotoxicity (inhibited head swinging, body bending frequency and acetylcholinesterase [AchE] activity) and reproductive toxicity (significant reductions in the number of eggs and offspring in vivo and induced apoptosis of gonadal cells). These phenomena caused oxidative damage (protein and membrane lipid peroxidation) and further induced apoptosis. The changes in various indicators caused by racemic glufosinate-ammonium exposure were more significant than those caused by l-glufosinate-ammonium exposure, and the reproduction-related indicators were more significant than the developmental and neurological indicators. A continuous accumulation of toxicity was observed after multiple generations of continuous exposure. These research results provide a data reference for the ecotoxicological evaluation and risk assessment of glufosinate-ammonium and contribute to the revision and improvement of the related environmental policies of glufosinate-ammonium.

Glyphosate based-herbicide disrupts energy metabolism and activates inflammatory response through oxidative stress in mice liver

Glyphosate, the most widely used herbicide worldwide, has been reported to cause hepatotoxicity. However, these systematic mechanisms remain poorly understood. Here, we investigated the effects of glyphosate-based herbicides (GBH) on liver toxicity in mice exposed to 0, 50, 250, and 500 mg/kg/day GBH for 30 d. Pathological and ultrastructural changes, serum biochemical indicators, oxidative stress state, and transcriptome and key protein alterations were performed to describe the hepatic responses to GBH. GBH induced hepatocytes structural alterations, vacuolation, and inflammatory, mitochondrial swelling and vacuolization; damaged liver function and aggravated oxidative stress; blocked the respiratory chain, promoted gluconeogenesis, fatty acid synthesis and elongation, and activated complement and coagulation cascades system (CCCS) in the liver. Moreover, SOD, H₂O₂, and MDA were negatively correlated with the CxI and CxIV genes, but positively correlated with the genes in glucolipid metabolism and CCCS pathways; however, the opposite results were observed for CAT, GSH-Px, and T-AOC. Overall, this study revealed the systematic mechanism underlying hepatotoxicity caused by GBH, providing new insights into understanding the hepatotoxicity of organophosphorus pesticide.

Biological effects of sub-lethal doses of glyphosate and AMPA on cardiac myoblasts

Introduction: Glyphosate is the active compound of different non-selective herbicides, being the most used agriculture pesticide worldwide. Glyphosate and AMPA (one of its main metabolites) are common pollutants of water, soil, and food sources such as crops. They can be detected in biological samples from both exposed workers and general population. Despite glyphosate acts as inhibitor of the shikimate pathway, present only in plants and some microorganisms, its safety in mammals is still debated. Acute glyphosate intoxications are correlated to cardiovascular/neuronal damages, but little is known about the effects of the chronic exposure. Methods: We evaluated the direct biological effects of different concentrations of pure glyphosate/AMPA on a rat-derived cell line of cardiomyoblasts (H9c2) in acute (1-2 h) or sub-chronic (24-48 h) settings. We analyzed cell viability/morphology, ROS production and mitochondrial dynamics. Results: Acute exposure to high doses (above 10 mM) of glyphosate and AMPA triggers immediate cytotoxic effects: reduction in cell viability, increased ROS production, morphological alterations and mitochondrial function. When exposed to lower glyphosate concentrations (1 μM-1 mM), H9c2 cells showed only a slight variation in cell viability and ROS production, while mitochondrial dynamic was unvaried. Moreover, the phenotype was completely restored after 48 h of treatment. Surprisingly, the sub-chronic (48 h) treatment with low concentrations (1 μM-1 mM) of AMPA led to a late cytotoxic response, reflected in a reduction in H9c2 viability. Conclusion: The comprehension of the extent of human exposure to these molecules remains pivotal to have a better critical view of the available data.