Glyphosate and AMPA distribution in wind-eroded sediment derived from loess soil

Glyphosate: Hepatotoxicity, Nephrotoxicity, Hemotoxicity, Carcinogenicity, and Clinical Cases of Endocrine, Reproductive, Cardiovascular, and Pulmonary System Intoxication

Glyphosate (GLP) is an active agent of GLP-based herbicides (GBHs), i.e., broad-spectrum and postemergent weedkillers, commercialized by Monsanto as, e.g., Roundup and RangerPro formulants. The GBH crop spraying, dedicated to genetically engineered GLP-resistant crops, has revolutionized modern agriculture by increasing the production yield. However, abusively administered GBHs' ingredients, e.g., GLP, polyoxyethyleneamine, and heavy metals, have polluted environmental and industrial areas far beyond farmlands, causing global contamination and life-threatening risk, which has led to the recent local bans of GBH use. Moreover, preclinical and clinical reports have demonstrated harmful impacts of GLP and other GBH ingredients on the gut microbiome, gastrointestinal tract, liver, kidney, and endocrine, as well as reproductive, and cardiopulmonary systems, whereas carcinogenicity of these herbicides remains controversial. Occupational exposure to GBH dysregulates the hypothalamic-pituitary-adrenal axis, responsible for steroidogenesis and endocrinal secretion, thus affecting hormonal homeostasis, functions of reproductive organs, and fertility. On the other hand, acute intoxication with GBH, characterized by dehydration, oliguria, paralytic ileus, as well as hypovolemic and cardiogenic shock, pulmonary edema, hyperkalemia, and metabolic acidosis, may occur fatally. As no antidote has been developed for GBH poisoning so far, the detoxification is mainly symptomatic and supportive and requires intensive care based on gastric lavage, extracorporeal blood filtering, and intravenous lipid emulsion infusion. The current review comprehensively discusses the molecular and physiological basics of the GLP- and/or GBH-induced diseases of the endocrine and reproductive systems, and cardiopulmonary-, nephro-, and hepatotoxicities, presented in recent preclinical studies and case reports on the accidental or intentional ingestions with the most popular GBHs. Finally, they briefly describe modern and future healthcare methods and tools for GLP detection, determination, and detoxification. Future electronically powered, decision-making, and user-friendly devices targeting major GLP/GBH's modes of actions, i.e., dysbiosis and the inhibition of AChE, shall enable self-handled or point-of-care professional-assisted evaluation of the harm followed with rapid capturing GBH xenobiotics in the body and precise determining the GBH pathology-associated biomarkers levels.

Glyphosate spraying exacerbates nitrogen and phosphorus loss in karst slope farmland

Glyphosate herbicide is an indispensable material in agricultural production. In order to explore the potential environmental effects of glyphosate application in karst slope farmland, this paper used a variable slope steel tank to simulate the surface microtopography and underground pore structure characteristics of karst slope farmland, and combined with artificial rainfall experiments to explore the migration path of glyphosate in karst slope farmland and the impact of spraying glyphosate on soil nitrogen and phosphorus loss. The results showed that under the condition of heavy rain, glyphosate in karst slope farmland was mainly transported and diffused by surface runoff, supplemented by underground runoff; secondly, in different hydrological paths, glyphosate directly affected the content of nitrogen and phosphorus in runoff, and all showed extremely significant positive correlation (p < 0.001). In addition, rainfall conditions such as rainfall intensity, rainfall duration, and runoff affected the content of nitrogen and phosphorus in runoff to varying degrees. In conclusion, the application of glyphosate significantly increased the content of nitrogen and phosphorus in different runoff and accelerated the loss of nitrogen and phosphorus from soil, which not only led to soil degradation, but also threatened the safety of aquatic ecosystem. Therefore, in the prevention and control of agricultural non-point source pollution, the threat of glyphosate to the surrounding aquatic ecosystem cannot be ignored, especially in karst areas with frequent rainstorms and serious water erosion, long-term monitoring and risk assessment of glyphosate are needed.

Epilithic biofilms as a discriminating matrix for long-term and growing season pesticide contamination in the aquatic environment: Emphasis on glyphosate and metabolite AMPA

The indiscriminate use of pesticides represents high ecological risk in aquatic systems. Recently, the inclusion of epilithic biofilms as a reactive matrix has shown potential in diagnosing the health of water resources. The objective of this study was to use multiple matrices (water, suspended sediments, and biofilms) to discriminate contamination degrees in catchments with long and recent history of intensive pesticide use and to monitor growing season pesticides transfer to watercourses. Two catchments were monitored: one representative of "modern agriculture" in a subtropical environment, and another representative of recent agricultural expansion over the Pampa Biome in subtropical Brazil. Glyphosate and AMPA were accumulated in the biofilms and were detected at all sites and at all monitoring times, in concentrations ranging from 195 to 7673 μg kg-1 and from 225 to 4180 μg kg-1, respectively. Similarly, the fungicide tebuconazole has always been found in biofilms. The biofilms made it possible to discriminate the long-term history of pesticide use in the catchments and even to identify the influx pulses of pesticides immediately after their application to crops, which was not possible with active water sampling and even with suspended sediment monitoring. It is strongly recommended that, in regions with intensive cultivation of soybeans and other genetically modified crops, the presence of glyphosate and its metabolite AMPA be permanently monitored, a practice still very scarce in the literature.

Glyphosate and environmental toxicity with "One Health" approach, a review

The herbicide Glyphosate (GLY), or N-(phosphonomethyl) glycine was synthesized in 1950 and applied to control weeds in agricultural production. For a long time, it was believed that it was an inert compound, but many studies have instead demonstrated over the years the dangers of GLY to the ecosystem and human health. Among the best-known effects, it is known that GLY interferes with the metabolic pathways of plants and the main groups of microorganisms, negatively influencing their growth. GLY interferes with the metabolic pathways of plants and major groups of microorganisms negatively affecting their growth. The extensive GLY application on fields results in a "slow death" of plants through the minor resistance to root pathogens and in increasing pollution of freshwaters and soils. Unfortunately, however, unlike the old beliefs, GLY can reach non-target destinations, in this regard, ecological studies and environmental epidemiology are of significant interest. In this review, we focus on the effects of acute and chronic exposure to GLY on the health of plants, animals, and humans from a One Health perspective. GLY has been linked to neurological and endocrine issues in both humans and animals, and behavioral modification on specific bioindicators, but the knowledge about the ratio cause-and-effect still needs to be better understood and elucidated. Environmental GLY residues analysis and policy acts will both require new criteria to protect environmental and human health.

Seasonal variations in the levels of glyphosate in soil, water and crops from three farm settlements in Oyo state, Nigeria

This study investigated the concentration of glyphosate in water (groundwater and surface), soil (top and sub) on cassava and maize farms within 3 farm settlements (Akufo, Ilora and Otiri Ipapo) from Ido, Oyo and Iseyin Local Government Areas of Oyo state, Nigeria. Samples of Top and sub soil were taken from the farms while water was collected from wells (groundwater) and streams (surface water) around each farm settlement using standard methods. Crops (cassava and Maize) samples were collected from each of the selected farm after harvest. The samples were collected over a six-month period to reflect seasonal variation. The glyphosate levels were determined using HPLC-FLD after liquid-liquid extraction technique for water and soxhlet extraction for soil crops The pH, electrical conductivity (EC), total dissolved solids (TDS) values for groundwater were within the WHO limits while values recorded for surface water were above the WHO limits. The phosphate and nitrate values were high in surface water compared to groundwater. High concentration of the exchangeable cations were recorded at the top soil for all the farms with values ranging from 4.0 ± 0.1 to 8.2 ± 0.0 for Ca2+, 2.9 ± 0.0 to 5.1 ± 0.1 for Mg2+, 0.3 ± 0.2 to 0.55 ± 0.0 for Na+, and 0.32 ± 0.0 to 8.2 ± 0.0 for K+. the residual concentration of glyphosate taken from wells and taps (groundwater) were within the maximum concentration of glyphosate in drinking water (0.7 mgL-1). Glyphosate concentrations observed were higher in soil samples from all farm settlements during wet season compared to dry, higher concentrations were also observed in surface water during wet season (August) compared to dry, with Akufo farm settlement having the highest concentrations of 29.40 ± 0.83 mgL-1. The glyphosate residues were also higher in cassava (0.3 ± 0.0 mgKg-1) compared to maize (0.07 ± 0.08 mgKg-1) across each farm settlement. Generally, the higher concentrations observed during wet season in both soil and water samples were as a result of active farm activities during wet season and run off respectively. If herbicide usage is not properly monitored within these settlements, it can pose a threat to aquatic animals and humans around the settlements, thus a sustainable and conservative farming is advised.

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.

Hazardous impacts of glyphosate on human and environment health: Occurrence and detection in food

With the ever-increasing human population, farming lands are decreasing every year, therefore, for effective crop management; agricultural scientists are continually developing new strategies. However, small plants and herbs always impart a much loss in the yields of the crop and farmers are using tons of herbicides to eradicate that problem. Across the world, several herbicides are available in the market for effective crop management, however, scientists observed various environmental and health effects of the herbicides. Over the past 40 years, the herbicide glyphosate has been used extensively with the assumption of negligible effects on the environment and human health. However, in recent years, concerns have increased globally about the potential direct and indirect effects on human health due to the excessive use of glyphosate. As well, the toxicity on ecosystems and the possible effects on all living creatures have long been at the center of a complex discrepancy about the authorization for its use. The World Health Organization also further classified glyphosate as a carcinogenic toxic component and it was banned in 2017 due to numerous life-threatening side effects on human health. In the present era, the residues of banned glyphosate are more prevalent in agricultural and environmental samples which are directly affecting human health. Various reports revealed the detailed extraction process of glyphosate from different categories of the food matrix. Therefore, in the present review, to reveal the importance of glyphosate monitoring in the food matrix, we discussed the environmental and health effects of glyphosate with acute toxicity levels. Also, the effect of glyphosate on aquatic life is discussed in detail and various detection methods such as fluorescence, chromatography, and colorimetric techniques from different food samples with a limit of detection values are revealed. Overall, this review will give an in-depth insight into the various toxicological aspects and detection of glyphosate from food matrix using various advanced analytical techniques.

Determination of glyphosate and AMPA in indoor settled dust by hydrophilic interaction liquid chromatography with tandem mass spectrometry and implications for human exposure

The widespread application of glyphosate leads to significant contamination of outdoor environmental compartments, notably air and soil, which can contaminate indoor air and dust. This study assessed the contamination of indoor household dust for the first time in France and potential exposure to glyphosate through the inadvertent ingestion of dust. A specific and new analytical method was developed using HILIC MS/MS (hydrophilic interaction liquid chromatography with tandem mass spectrometry) to measure polar pesticides, such as glyphosate, aminomethylphosphonic acid, and glufosinate, in indoor dust, with a low quantification limit (25 ng/g). The dust from vacuum cleaner bags of 60 rural and urban households (Brittany, France) was analyzed. All samples contained glyphosate (median 1675 ng/g for rural dwellings (n = 29), 457 ng/g for urban dwellings (n = 31)), more than 90 % contained aminomethylphosphonic acid, and none contained glufosinate. Concentrations were influenced by the rural or urban setting, the proximity of crops, and the use of weed killers on driveways or lawns. Glyphosate exposure via indoor dust ingestion was < 1 % of both acceptable daily intake and dietary intake. However, the high quantification limit of the glyphosate concentration in the food analysis method probably leads to overestimation of the dose from food.

Association of Lifetime Exposure to Glyphosate and Aminomethylphosphonic Acid (AMPA) with Liver Inflammation and Metabolic Syndrome at Young Adulthood: Findings from the CHAMACOS Study

BACKGROUND

The prevalence of liver disorders and metabolic syndrome has increased among youth. Glyphosate, the most widely used herbicide worldwide, could contribute to the development of these conditions.

OBJECTIVE

We aimed to assess whether lifetime exposure to glyphosate and its degradation product, aminomethylphosphonic acid (AMPA), is associated with elevated liver transaminases and metabolic syndrome among young adults.

METHODS

We conducted a prospective cohort study (n = 480 mother-child dyads) and a nested case-control study (n = 60 cases with elevated liver transaminases and 91 controls) using data from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS). We measured glyphosate and AMPA concentrations in urine samples collected during pregnancy and at child ages 5, 14, and 18 y from cases and controls. We calculated glyphosate residue concentrations: [glyphosate  +   ( 1.5 × AMPA ) ]. We estimated the amount of agricultural-use glyphosate applied within a 1 - km radius of every residence from pregnancy to age 5 y for the full cohort using California Pesticide Use Reporting data. We assessed liver transaminases and metabolic syndrome at 18 y of age.

RESULTS

Urinary AMPA at age 5 y was associated with elevated transaminases [relative risk (RR) per 2 - fold increase = 1.27 , 95% confidence interval (CI): 1.06, 1.53] and metabolic syndrome (RR = 2.07 , 95% CI: 1.38, 3.11). Urinary AMPA and glyphosate residues at age 14 y were associated with metabolic syndrome [RR = 1.80 (95% CI: 1.10, 2.93) and RR = 1.88 (95% CI: 1.03, 3.42), respectively]. Overall, a 2-fold increase in urinary AMPA during childhood was associated with a 14% and a 55% increased risk of elevated liver transaminases and metabolic syndrome, respectively. Living near agricultural glyphosate applications during early childhood (birth to 5 y of age) was also associated with metabolic syndrome at age 18 y in the case-control group (RR = 1.53 , 95% CI: 1.16, 2.02).

DISCUSSION

Childhood exposure to glyphosate and AMPA may increase risk of liver and cardiometabolic disorders in early adulthood, which could lead to more serious diseases later in life. https://doi.org/10.1289/EHP11721.

Microplastic appraisal of soil, water, ditch sediment and airborne dust: The case of agricultural systems

Although microplastic pollution jeopardizes both terrestrial and aquatic ecosystems, the movement of plastic particles through terrestrial environments is still poorly understood. Agricultural soils exposed to different managements are important sites of storage and dispersal of microplastics. This study aimed to identify the abundance, distribution, and type of microplastics present in agricultural soils, water, airborne dust, and ditch sediments. Soil health was also assessed using soil macroinvertebrate abundance and diversity. Sixteen fields were evaluated, 6 of which had been exposed to more than 5 years of compost application, 5 were exposed to at least 5 years of plastic mulch use, and 5 were not exposed to any specific management (controls) within the last 5 years. We also evaluated the spread of microplastics from the farms into nearby water bodies and airborne dust. We found 11 types of microplastics in soil, among which Light Density Polyethylene (LDPE) and Light Density Polyethylene covered with pro-oxidant additives (PAC) were the most abundant. The highest concentrations of plastics were found in soils exposed to plastic mulch management (128.7 ± 320 MPs.g-¹ soil and 224.84 ± 488 MPs.g-¹ soil, respectively) and the particles measured from 50 to 150 μm. Nine types of microplastics were found in water, with the highest concentrations observed in systems exposed to compost. Farms applying compost had higher LDPE and PAC concentrations in ditch sediments as compared to control and mulch systems; a significant correlation between soil polypropylene (PP) microplastics with ditch sediment microplastics (r² 0.7 p < 0.05) was found. LDPE, PAC, PE (Polyethylene), and PP were the most abundant microplastics in airborne dust. Soil invertebrates were scarce in the systems using plastic mulch. A cocktail of microplastics was found in all assessed matrices.

Can calcite play a role in the adsorption of glyphosate? A comparative study with a new challenge

Calcite as a sorbent can interact with both inorganic and organic substances through their functional groups. To measure its adsorption ability, another sorbent, saponite was selected because it can sorb glyphosate, an organic compound with a polar molecule and widely used as a herbicide. In this study, the two sorbents calcite and saponite were saturated by calcium chloride, and characterized by SEM-EDX, X-ray diffraction, and Zeta Potential Analyzer to investigate their capacity to sorb glyphosate. After saturation, the saponite became homoionic Ca-saponite with minor changes in morphology and specific surface area. But, the morphology of calcite transformed from rhombohedron to scalenohedron, with an increase of 75-folds in its specific surface, and the zeta potential became positive in alkaline pH, which contradicts the results of all previous research. The modified sorbents (Ca-calcite and Ca-saponite) were added to two soil samples to investigate each sorbent's effect on glyphosate sorption. Adsorption isotherm and percentage of glyphosate desorbed revealed the difference in binding and adsorption sites. The Langmuir and Temkin models fitted isotherm data in low concentrations better and suggested chemosorption for the uptake of glyphosate. FTIR analyses of samples with and without glyphosate were compared and results suggested that the bulk of adsorption happened in siloxane groups and on calcium carbonates surfaces.

Human serum lipidomics analysis revealed glyphosate may lead to lipid metabolism disorders and health risks

Glyphosate-based herbicides (GBH) are one of the most widely used pesticides worldwide. Industrial workers in glyphosate-based herbicides manufacture are the populations who experience long-term exposure to high glyphosate levels. The impacts of glyphosate on human health are the important public health problem of great concern. Up to date, the potential adverse effects of glyphosate on humans or other mammals have been reported in multiple studies. However, limited research is available on lipid alternations related to human exposure to glyphosate. In fact, the perturbations in some lipid metabolisms have been found in industrial workers in previous work. This study aims to explore the serum lipidomic characterization and to understand the underlying mechanisms of health risks associated with glyphosate exposure. A nontargeted lipidomics study was conducted to investigate the 391 serum samples from the general population and chemical factory workers. It was demonstrated that glyphosate caused significant perturbations of 115 differentially expressed lipids. The main manifestations were the elevation of circulating diacylglycerols (DG), cholesteryl esters (CE), ceramides (Cer), sphingomyelins (SM), lysophosphatidylethanolamines (LPE) and phosphatidylcholines (PC), and the decrease of ysophosphatidylcholines (LPC), triacylglycerols (TG), fatty acids (FA) and phosphatidylethanolamines (PE). A total of 88 lipids were further screened as potential lipid biomarkers associated closely with glyphosate using partial correlation analysis, and five of which (including PC 16:0/18:2; O, PC 18:0/18:2; O, PC 18:0/20:4; O, PC O-40:9 and CE 18:3) showed excellent superior performance (AUC = 1) to evaluate and monitor health risks due to glyphosate exposure. The present work discovered glyphosate-induced potential health risks, including chronic hepatic and renal dysfunction, atherosclerosis, cardiovascular disease and neurodegenerative diseases from a lipidomic perspective, and could inform the identification of early indicators and interpretation of biological mechanisms to detect health risks of the glyphosate-exposed populations as early as possible.

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.

Herbicide residues in Australian grain cropping soils at sowing and their relevance to crop growth

Herbicides are used extensively in Australian grain cropping systems. Despite occasional observations of herbicide-induced phytotoxicity, there is little information on the persistence and carryover of multiple herbicide classes in cropping soils and the risk to subsequent crops. Two soil surveys were conducted, in 2015 (n = 40) and 2016 (n = 42), across different Australian grain cropping fields prior to sowing of winter crops, and soil samples analysed for herbicide residues (16 analytes in 2015 and 22 analytes in 2016). Samples in 2015 were taken at two depths (0-10 cm and 10-30 cm), whilst samples in 2016 were taken in topsoil (0-10 cm) only, but from two discrete locations in each field. Our research in both years found at least one herbicide (or herbicide metabolite) residue at all sites, with a median of 6 analytes detected in 2015 and 7 analytes detected in 2016. The most frequently detected residues were glyphosate and its primary breakdown product aminomethylphosphonic acid (AMPA), in 87 and 100%, respectively, of topsoil (0-10 cm) samples in 2015, and 67 and 93% of samples in 2016. The median concentration of glyphosate in 2015 was 0.12 mg kg^-1, while AMPA was 0.41 mg kg^-1. In 2016, median concentrations of glyphosate and AMPA were 0.22 mg kg^-1 and 0.31 mg kg^-1. Residues of 2,4-dichlorophenoxyacetic acid, trifluralin and diflufenican were also detected in >40% of topsoil samples in both seasons, but with median concentrations of <0.05 mg kg^-1. A literature review found limited availability of phytotoxicity thresholds for major grain crops exposed to soilborne herbicide residues. A risk assessment using available thresholds suggested that although up to 29% of fields contained trifluralin residues that could constrain cereal crop growth, and 24% of fields contained residues of phenoxy or sulfonylureas that could affect dicotyledonous crops, the majority of these fields when planted with tolerant crops would be unlikely to be affected by herbicide residues. More work is required to ascertain the spatial distribution, bioavailability and phytotoxicity of residues and residue mixtures to enable a more accurate agronomic risk assessment.

The study of human serum metabolome on the health effects of glyphosate and early warning of potential damage

Glyphosate is one of the most widely used herbicide with high efficiency, low toxicity and broad-spectrum. In recent decades, increasing evidence suggests that glyphosate may cause adverse health effects on human beings. However, until now, there is little data on the human metabolic changes. Since occupational workers are under greater health risks than ordinary people, the understanding regarding the health effects of glyphosate on occupational workers is very important for the early warning of potential damage. In this study, serum metabolic alterations in workers from three chemical factories were analyzed by gas chromatography-mass spectrometry (GC-MS) to assess the potential health risks caused by glyphosate at the molecular level. It was found that the levels of 27 metabolites changed significantly in the exposed group compared to the controls. The altered metabolic pathways, including amino acid metabolism, energy metabolism (glycolysis and TCA cycle) and glutathione metabolism (oxidative stress), etc., indicated a series of changes occur in health profile of the human body after glyphosate exposure, and the suboptimal health status of human may further evolve into various diseases, such as Parkinson's disease, renal and liver dysfunction, hepatocellular carcinoma, and colorectal cancer. Subsequently, 4 biomarkers (i.e., benzoic acid, 2-ketoisocaproic acid, alpha-ketoglutarate, and monoolein) were identified as potential biomarkers related to glyphosate exposure based on the partial correlation analyses, linear regression analyses, and FDR correction. Receiver-operating curve (ROC) analyses manifested that these potential biomarkers and their combinational pattern had good performance and potential clinical value to assess the potential health risk associated with glyphosate exposure while retaining high accuracy. Our findings provided new insights on mechanisms of health effects probably induced by glyphosate, and may be valuable for the health risk assessment of glyphosate exposure.

Phosphate addition enhances alkaline extraction of glyphosate from highly sorptive soils and aquatic sediments

BACKGROUND

Analytical constraints complicate environmental monitoring campaigns of the herbicide glyphosate and its major degradation product aminomethylphosphonic acid (AMPA): their strong sorption to soil minerals requires harsh extraction conditions. Coextracted matrix compounds impair downstream analysis and must be removed before analysis.

RESULTS

A new extraction method combined with subsequent capillary electrophoresis-mass spectrometry for derivatization-free analysis of glyphosate and AMPA in soil and sediment was developed and applied to a suite of environmental samples. It was compared to three extraction methods from literature. We show that no extraction medium reaches 100% recovery. The new phosphate-supported alkaline extraction method revealed (1) high recoveries of 70-90% for soils and aquatic sediments, (2) limits of detections below 20 μg kg-1 , and (3) a high robustness, because impairing matrix components (trivalent cations and humic acids) were precipitated prior to the analysis. Soil and sediment samples collected around Tübingen, Germany, revealed maximum glyphosate and AMPA residues of 80 and 2100 μg kg-1 , respectively, with residues observed along a core of lake sediments. Glyphosate and/or AMPA were found in 40% of arable soils and 57% of aquatic sediment samples.

CONCLUSION

In this work, we discuss soil parameters that influence (de)sorption and thus extraction. From our results we conclude that residues of glyphosate in environmental samples are easily underestimated. With its possible high throughput, the method presented here can resolve current limitations in monitoring campaigns of glyphosate by addressing soil and aquatic sediment samples with critical sorption characteristics.

Glyphosate and AMPA exposure in relation to markers of biological aging in an adult population-based study

BACKGROUND/AIM

Glyphosate, a broad-spectrum herbicide, and its main metabolite aminomethylphosphonic acid (AMPA) are persistent in the environment. Studies showed associations between glyphosate or AMPA exposure and several adverse cellular processes, including metabolic alterations and oxidative stress.

OBJECTIVE

To determine the association between glyphosate and AMPA exposure and biomarkers of biological aging.

METHODS

We examined glyphosate and AMPA exposure, mtDNA content and leukocyte telomere length in 181 adults, included in the third cycle of the Flemish Environment and Health Study (FLEHSIII). DNA was isolated from leukocytes and the relative mtDNA content and telomere length were determined using qPCR. Urinary glyphosate and AMPA concentrations were measured by Gas Chromatography-Tandem Mass Spectrometry (GC-MS-MS). We used multiple linear regression models to associate mtDNA content and leukocyte telomere length with glyphosate or AMPA exposure while adjusting for confounding variables.

RESULTS

A doubling in urinary AMPA concentration was associated with 5.19% (95% CI: 0.49 to 10.11; p = 0.03) longer leukocyte telomere length, while no association was observed with urinary glyphosate concentration. No association between mtDNA content and urinary glyphosate nor AMPA levels was observed.

CONCLUSIONS

This study showed that AMPA exposure may be associated with telomere biology in adults.

Predicting wind erosion rate using portable wind tunnel combined with machine learning algorithms in calcareous soils, southern Iran

Wind erosion is a critical factor in land degradation worldwide, particularly in arid and semi-arid regions of southern Iran, which have been severely exposed to wind erosion in the recent years due to climate change and land use changes. The main objective of the present study was to predict the wind erosion rate (WER) using easily measurable soil properties combined with some data mining approaches. For this purpose, the WER was measured at 100 locations with different land uses and soil types in the Fars Province, southern Iran using a portable wind tunnel. The WER was predicted by multiple linear regression (MLR), support vector regression (SVR) and decision tree (DT) algorithms using easily measurable soil properties. Results revealed that land use and soil type had significant effect on the WER. The highest mean WER was observed in Entisols with the lowest organic matter (OM), the lowest penetration resistance (PR) and the lowest aggregate mean weight diameter (MWD). Bare lands with the lowest OM and MWD showed the highest WER compared to other land uses. R² and RMSE of the non-linear regression models developed based on the type of the relationship between the WER and easily measurable soil properties improved by 15% and 12%, respectively, compared to the linear regression model. In both train and test datasets, the SVR and DT models coupled to a genetic algorithm (GA) used for selecting the effective easily measurable soil properties had higher performance than the SVR and DT models using all easily measurable soil properties for predicting WER. With respect to statistical indices, the SVR model with R² = 0.91 and RMSE = 0.68 g m^-2 s^-1 outperformed the MLR and DT for predicting the WER. We concluded that combining the SVR with GA could be an applicable and promising method for predicting WER.

First evidence of glyphosate and aminomethylphosphonic acid (AMPA) in the respirable dust (PM10) emitted from unpaved rural roads of Argentina

The aim of this work was to compare the concentration of glyphosate and AMPA in the PM10 and the actual PM10 emission from agricultural soils and unpaved roads, located inside and outside farm fields. To determine the actual PM10 emission by wind erosion, the actual wind erosion was estimated using the Wind Erosion Equation, and the PM10 emission efficiency was measured with the Easy Dust Generator. PM10 was collected in an electrostatic precipitator coupled to the Easy Dust Generator. Actual PM10 emission was 11.5 g ha^-1 year^-1 in agricultural soils and 4711.4 g ha^-1 year^-1 in unpaved roads. The high value of actual PM10 emission in unpaved roads was due to their high actual wind erosion and the high PM10 emission efficiency, while the low value in agricultural soils was due to their low actual wind erosion. Content of glyphosate in the PM10 ranged from 59 to 359 μg kg^-1 in agricultural soils, from 382 to 454 μg kg^-1 in unpaved roads inside farm fields, and from 39 to 639 μg kg^-1 in unpaved roads outside farm fields. Content of AMPA in the PM10 ranged from 387 to 7228 μg kg^-1 in agricultural soils, from 900 to 4138 μg kg^-1 in unpaved roads inside farm fields, and 98 to 500 μg kg^-1 in unpaved roads outside farm fields. AMPA concentration in PM10 was higher than that of glyphosate due to the longer persistence of AMPA than glyphosate. Glyphosate and AMPA concentrations in PM10 were higher than in soil, which is an additional risk that should be considered when the effect of PM10 emitted by agricultural soils and unpaved roads on human health are evaluated. Our results show that the amount and chemical composition of PM10 emitted by wind erosion from unpaved roads should be studied in other regions.

Glyphosate, aminomethylphosphonic acid, and glufosinate ammonium in agricultural groundwater and surface water in China from 2017 to 2018: Occurrence, main drivers, and environmental risk assessment

Glyphosate and glufosinate ammonium are the main herbicides used to control weeds in no-tillage agricultural fields in China. However, their leaching risk to groundwater and ecological risk to aquatic organisms remain unclear. From the agricultural basins among 10 provinces of China, glyphosate, its main metabolite aminomethylphosphonic acid (AMPA), and glufosinate ammonium were detected in 1.01%, 0.86%, 0% of 694 groundwater samples with the maximum concentrations of 2.09, 5.13, and <0.05 μg/L, and were detected in 14.3%, 15.8%, and 2.6% of 196 surface water samples with the maximum levels of 32.49, 10.31 and 13.15 μg/L. Furthermore, to evaluate the main drivers of exposure to the targets in water bodies, the fate models were used. The model simulation indicated that spray drift and overflow runoff were the key factors affecting the exposure to targets in surface water adjacent to rice field, whereas the spray drift deposition, runoff, and erosion induced the exposure to the targets in pond water close to dry land crop fields under different meteorological conditions and soil characteristics. The targets in groundwater posed a low risk to water consumption, while fish embryos might be at unacceptable risk due to glufosinate ammonium exposure in surface water with median risk quotient (RQ) equal to 55.6. The results highlight the spatial and seasonal distribution of glyphosate, AMPA, and glufosinate ammonium in groundwater and surface water in agricultural basins of China, providing the first evidence to the environmental risk of the targets to drinking water consumption and aquatic organism safety in China agriculture system.

Pesticides in a case study on no-tillage farming systems and surrounding forest patches in Brazil

With the growing global concern on pesticide management, the relationship between its environmental recalcitrance, food security and human health has never been more relevant. Pesticides residues are known to cause significant environmental contamination. Here, we present a case study on long-term no-tillage farming systems in Brazil, where Glyphosate (GLY) has been applied for more than 35 years. GLY and its main breakdown product, aminomethylphosphonic acid (AMPA) were determined in topsoil (0-10 cm) samples from no-tillage fields and nearby subtropical secondary forests by high-performance liquid chromatography coupled with a fluorescence detector. In addition, the presence of carbamates, organochlorines, organophosphates and triazines were also screened for. GLY and AMPA were present in all soil samples, reaching values higher than those described for soils so far in the literature. A significant decrease for AMPA was observed only between the secondary forest and the farm's middle slope for site B. GLY and AMPA were observed respectively at peak concentrations of 66.38 and 26.03 mg/kg soil. GLY was strongly associated with forest soil properties, while AMPA associated more with no-tillage soil properties. Soil texture was a significant factor contributing to discrimination of the results as clay and sand contents affect GLY and AMPA retention in soils. This was the first study to report DDT and metabolites in consolidated no-tillage soils in Brazil (a pesticide fully banned since 2009). Based on human risk assessment conducted herein and the potential risk of GLY to local soil communities, this study offers a baseline for future studies on potential adverse effects on soil biota, and mechanistic studies.

Are glyphosate and glyphosate-based herbicides endocrine disruptors that alter female fertility?

Numerous evidences have alerted on the toxic effects of the exposure to glyphosate on living organisms. Glyphosate is the herbicide most used in crops such as maize and soybean worldwide, which implies that several non-target species are at a high risk of exposure. Although the Environmental Protection Agency (EPA-USA) has reaffirmed that glyphosate is safe for users, there are controversial studies that question this statement. Some of the reported effects are due to exposure to high doses; however, recent evidences have shown that exposure to low doses could also alter the development of the female reproductive tract, with consequences on fertility. Different animal models of exposure to glyphosate or glyphosate-based herbicides (GBHs) have shown that the effects on the female reproductive tract may be related to the potential and/or mechanisms of actions of an endocrine-disrupting compound. Studies have also demonstrated that the exposure to GBHs alters the development and differentiation of ovarian follicles and uterus, affecting fertility when animals are exposed before puberty. In addition, exposure to GBHs during gestation could alter the development of the offspring (F1 and F2). The main mechanism described associated with the endocrine-disrupting effect of GBHs is the modulation of estrogen receptors and molecules involved in the estrogenic pathways. This review summarizes the endocrine-disrupting effects of exposure to glyphosate and GBHs at low or "environmentally relevant" doses in the female reproductive tissues. Data suggesting that, at low doses, GBHs may have adverse effects on the female reproductive tract fertility are discussed.

Ecotoxicological Assessment of a Glyphosate-Based Herbicide in Cover Plants: Medicago sativa L. as a Model Species

Despite the several innovations that have been incorporated in agriculture, the use of herbicides, especially glyphosate (GLY), is still the major tool for weed control. Although this herbicide has a notable worldwide representation, concerns about its environmental safety were recently raised, with a lot of divergence between studies on its non-target toxicity. Therefore, it is of utmost importance to understand the risks of this herbicide to non-target plants, including cover crop species, which have a crucial role in maintaining agroecosystems functions and in preventing soil erosion. Thus, this work aims to evaluate the growth and physiological responses of a cover plant species (Medicago sativa L.) exposed to increasing concentrations of a GLY-based herbicide (GBH), particularly focusing on the oxidative metabolism. The growth of roots and shoots was affected, being this effect accompanied by a rise of lipid peroxidation, suggesting the occurrence of oxidative stress, and by an activation of the antioxidant (AOX) system. Indeed, the results showed that adverse effects are visible at active ingredient concentrations of 8.0 mg kg−1, with the lowest EC50 being 12 mg kg−1, showing that GBH-contaminated soils may pose a risk to the survival of non-target plants in the most contaminated areas. Overall, these findings proved that GBH greatly impairs the growth of a non-target plant, strengthening the need of additional studies to unravel the real risks associated with the over usage of this pesticide, since there is an evident lack of studies performed with contaminated soils.

Hydrogeological features affecting spatial distribution of glyphosate and AMPA in groundwater and surface water in an agroecosystem. Córdoba, Argentina

The study area is located in the eastern slope of Las Peñas Mountain and its adjacent oriental fluvio-aeolian-plain. Agriculture is the main activity (soybean, maize, wheat, peanuts and alfalfa) with no-tillage farming and intensive use of agrochemicals (pesticides-fertilizers). Glyphosate (N-phosphono-methylglycine) is the most common used herbicide which suffers microbial biodegradation giving aminomethylphosphonic acid (AMPA), its main metabolite. The objective of this work is to evaluate hydrogeological features which influence the presence of glyphosate and AMPA in waters. In the study area, the main flow direction of surface and groundwater is NW-SE. The unsaturated zone thickness decreases in the same direction from 60 to 0 m, so groundwater surges in low areas in the eastern sector. From the total water samples collected, glyphosate was detected in 66% of surface water samples (0.2 to 167.4 μg/L), in 15.8% of the groundwater samples (1.3 to 2 μg/L) and in the harvested precipitation sample (0.2 μg/L). AMPA was found in 33% of surface water and 15.8% of groundwater. The herbicide detection was related to areas with the shallowest water table (< 4 m), low hydraulic conductivity in the aquifer (K = 1.5 m/d), low hydraulic gradient (i = 0.16%) and very low flow velocity (0.02 m/d). The most outstanding result is that the groundwater presents higher values in comparison with the surface water samples, which can be explained by the greater dilution capacity of streams. The detection of glyphosate and AMPA in the unconfined aquifer shows that the application for decades under the prevailing agricultural model exceeds the degradation potential of the soil and the unsaturated zone, causing groundwater contamination.

The impact of pesticides used at the agricultural land of the Puck commune on the environment of the Puck Bay

Background

The Puck commune is one of the largest agricultural regions in the Pomeranian Voivodship that due to the pollution of the coastal zone negatively affects the functioning of the Puck Bay, including health of its inhabitants, and causes decrease in tourism as well as in overall economic value of the region. The objective of the undertaken study was to assess the extent of risk to the environment posed by the pesticides used in agricultural production in the coastal area of the Puck commune.

Methods

The study focused on organochlorine insecticides (DDT and its metabolites: α, β, ϒ, δ-HCH, aldrin, dieldrin, endrin, isodrine), glyphosate and its metabolite AMPA, and 309 active substances used as pesticides. Analyses were carried out using GC-MS, GC-MS/MS and LC-MS/MS techniques. The undertaken novel approach included “tracking” of a large number of substances in multiple environmental matrices (surface water, groundwater, seawater, soil, sediment and fish), along with examination of their transport routes from the pesticides application locality to the Puck Bay.

Results

Glyphosate and its metabolite AMPA, anthraquinone, boscalid, chlorpyrifos-ethyl, dimethachlor, diflufenican, difenoconazole, epoxiconazole, fluopicolide and metazachlor were found in soil samples and surface water samples collected from drainage ditches surrounding the studied agricultural plots. In the samples of seawater and fish taken from the Puck Bay no studied pesticides were found.

Glyphosate and aminomethylphosphonic acid (AMPA) are commonly found in urban streams and wetlands of Melbourne, Australia

Glyphosate is the most widely-used pesticide for weed control in agriculture and in urban and residential areas. This is the first study to quantify glyphosate and AMPA levels in surface water in Australia from different land uses. Glyphosate and AMPA was measured in surface water from 10 rural streams, 30 urban stormwater wetlands and 9 urban streams located in and around the city of Melbourne, Australia on five occasions between October 2017 and February 2018. Glyphosate and AMPA were present in most of the urban surface water samples. The frequency of detection of glyphosate was 77% in wetlands and 79% in urban streams, whereas it was only detected in 4% of the rural streams. Similarly, AMPA detection was 91% in wetlands and 97% in urban streams, whereas it was only present in 6% of the rural stream samples. In both urban streams and wetlands, the highest average glyphosate concentrations occurred in November (1.8 ± 2.2 μg L-1). Overall, wetlands and streams associated with urban land use are vulnerable to glyphosate contamination. These results highlight the importance of screening for contaminants in urban stormwater to identify the source of pollutants that may end up in aquatic ecosystems and the risks therefrom.

Modeling the mobility of glyphosate from two contrasting agricultural soils in laboratory column experiments

Glyphosate (GLP) currently is one of the most widely used herbicides worldwide. The persistence of GLP and its major metabolite, aminomethylphosphonic acid (AMPA) in the environment has been described by other authors. This study was aimed at comparing the GLP and AMPA behavior in sandy and loamy sand soils after spiking with enhanced (445 µg g-1) concentrations of GLP in herbicide KLINIK® (Nufarm, Austria) and bioaugmentation followed by 40 days weathering and a consistent three-stage leaching in a laboratory column experiment. Soil samples were obtained from mineral topsoil (0-10 cm) within former agricultural lands where soil parent material was formed by glacigenic deposits. The total amount of GLP and AMPA collected during three leaching stages was significantly (p<.05) higher from columns with sandy soil, compared to loamy sand soil. Bioaugmentation resulted in considerably lower concentrations of AMPA in leachates, especially in the sets with sandy soil (p=.01). Leachates were tested using FTIR spectroscopy and Daphnia magna. Statistical analysis of the changes in Ntot, Ctot, K+, Mg2+, Al3+, Ca2+, Mn2+ and Fe3+ concentrations in soils after the leaching experiment revealed that the loamy sand soil was likely to be more sensitive to the addition of GLP and bioaugmentation than sandy soil.

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

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

Wind erosion as a driver for transport of light density microplastics

Microplastic pollution in the environment is a growing concern in today's world. Wind-eroded sediment, as an environmental transport pathway of microplastics, can result in environmental and human exposure far beyond its sources. For the first time, this study investigates the presence of microplastics in wind-eroded sediments from different land uses in the Fars Province, Iran. Eleven test plots were selected based on land use and wind erosion risk. On each plot, wind erosion was simulated using a portable wind tunnel and the eroded sediment was collected for further analysis aimed at measuring light density microplastics (LDMP). The LDMPs were extracted in both soil and wind-eroded sediment using a floatation method and then further examined using microscopy. Annual LDMP transport by wind erosion was estimated using wind data from the study areas. LDMPs were detected in six study areas in the Fars Province which are highly prone to wind erosion. Although LDMPs were found mostly in agricultural land, it was also detected in the soils and sediments from two natural areas. The total concentrations of LDMPs in polluted areas were 6.91 and 20.27 mg kg^-1 of microplastics in soil and wind-eroded sediments, respectively. The enrichment ratio for LDMP ranged from 2.83 to 7.63 in different areas. The erosion rate of LDMP ranged from 0.08 to 1.48 mg m^-2 min^-1. The results of this study confirmed the key role of wind erosion in the spread of microplastics in terrestrial environments which could form an exposure risk to humans via direct inhalation of the particles transported with the dust.

Biogeochemistry of soil organic matter in agroecosystems & environmental implications

The biogeochemistry of soil organic matter (SOM), as a highly complex and dynamic soil property, is of vital importance for the health and ecological functioning of ecosystems, including managed and natural ones. Dominantly composed of carbon (C), SOM functions in global C cycling, including C sequestration and emission (e.g. soil respiration). Mediterranean agroecosystems especially, due to favourable climate conditions for mineralisation of SOM, are expected to go through enhanced SOM decomposition (i.e. C emission) under the ongoing global warming and related climatic change and variability (frequent heat waves, fires and extreme water disturbances). The relatively stable (humified) SOM components, especially in the organically-enriched topsoil layers, due to their specific physical chemistry (strongly charged interface) may have a significant role in biogeochemistry of charged (in)organic nutrients and/or contaminants such as toxic metal ions and persistent organic pollutants. The recent studies show that some natural vulnerabilities of Mediterranean regions (such as high risk of the erosion-driven processes) can increase movement of some hazardous pedospheric constituents (e.g. pesticides) to water bodies and/or into the air, thus influencing the whole ecosystem health. A majority of recent surveys confirm depletion of SOM and spatially variable distribution of metal contamination in the Mediterranean topsoils. Using the advanced geochemical prediction approaches in combination with the relevant soil databases, we characterised organo-mineral and organo-metal complexation and its effect on speciation and sorption of trace metals in karstified Mediterranean agroecosystems. Metal biogeochemistry was found to vary markedly under relatively constant pedosphere conditions, depending on organo-mineral soil components and pH, which may significantly impact metal mobility/availability in the soil-plant continuum. The knowledge of the SOM spatial distribution and dynamics and its interactions with other pedovariables is essential for sustainable management of SOM and control of contaminant mobility to avoid degradation processes in (agro)ecosystems.

Pesticide residues in European agricultural soils - A hidden reality unfolded

Pesticide use is a major foundation of the agricultural intensification observed over the last few decades. As a result, soil contamination by pesticide residues has become an issue of increasing concern due to some pesticides' high soil persistence and toxicity to non-target species. In this study, the distribution of 76 pesticide residues was evaluated in 317 agricultural topsoil samples from across the European Union. The soils were collected in 2015 and originated from 11 EU Member States and 6 main cropping systems. Over 80% of the tested soils contained pesticide residues (25% of samples had 1 residue, 58% of samples had mixtures of two or more residues), in a total of 166 different pesticide combinations. Glyphosate and its metabolite AMPA, DDTs (DDT and its metabolites) and the broad-spectrum fungicides boscalid, epoxiconazole and tebuconazole were the compounds most frequently found in soil samples and the compounds found at the highest concentrations. These compounds occasionally exceeded their predicted environmental concentrations in soil but were below the respective toxic endpoints for standard in-soil organisms. Maximum individual pesticide content assessed in a soil sample was 2.05 mg kg^-1 while maximum total pesticide content was 2.87 mg kg^-1. This study reveals that the presence of mixtures of pesticide residues in soils are the rule rather than the exception, indicating that environmental risk assessment procedures should be adapted accordingly to minimize related risks to soil life and beyond. This information can be used to implement monitoring programs for pesticide residues in soil and to trigger toxicity assessments of mixtures of pesticide residues on a wider range of soil species in order to perform more comprehensive and accurate risk assessments.

Biogenic transport of glyphosate in the presence of LDPE microplastics: A mesocosm experiment

The accumulation of plastic debris and herbicide residues has become a huge challenge and poses many potential risks to environmental health and soil quality. In the present study, we investigated the transport of glyphosate and its main metabolite, aminomethylphosphonic acid (AMPA) via earthworms in the presence of different concentrations of light density polyethylene microplastics in the litter layer during a 14-day mesocosm experiment. The results showed earthworm gallery weight was negatively affected by the combination of glyphosate and microplastics. Glyphosate and AMPA concentrated in the first centimetre of the top soil layer and the downward transport of glyphosate and AMPA was only detected in the earthworm burrows, ranging from 0.04 to 4.25 μg g-1 for glyphosate and from 0.01 (less than limit of detection) to 0.76 μg g-1 for AMPA. The transport rate of glyphosate (including AMPA) from the litter layer into earthworm burrows ranged from 6.6 ± 4.6% to 18.3 ± 2.4%, depending on synergetic effects of microplastics and glyphosate application. The findings imply that earthworm activities strongly influence pollutant movement into the soil, which potentially affects soil ecosystems. Further studies focused on the fate of pollutants in the microenvironment of earthworm burrows are needed.

Dynamics of glyphosate and AMPA in the soil surface layer of glyphosate-resistant crop cultivations in the loess Pampas of Argentina

This study investigates the dynamics of glyphosate and AMPA in the soil surface layer of two fields growing glyphosate-resistant crops in the loess Pampas of Córdoba Province, Argentina. Glyphosate decay and AMPA formation/decay were studied after a single application, using decay kinetic models. Furthermore, glyphosate and AMPA concentrations were investigated in runoff to evaluate their off-site risk. During a 2.5-month study, cultivations of glyphosate-resistant soybean and maize received an application of 1.0 and 0.81 kg a.e. ha-1, respectively, of Roundup UltraMax©. Topsoil samples (0-1, 1-2 cm) were collected weekly (including before application) and analysed for glyphosate, AMPA and soil moisture (SM) contents. Runoff was collected from runoff plots (3 m2) and weirs after 2 erosive rainfall events, and analysed for glyphosate and AMPA contents (water, eroded-sediment). Under both cultivations, background residues in soil before application were 0.27-0.42 mg kg-1 for glyphosate and 1.3-1.7 mg kg-1 for AMPA. In the soybean area, the single-first-order (SFO) model performed best for glyphosate decay. In the maize area, the bi-phasic Hockey-Stick (HS) model performed best for glyphosate decay, due to an abrupt change in SM regimes after high rainfall. Glyphosate half-life and DT90 were 6.0 and 19.8 days, respectively, in the soybean area, and 11.1 and 15.4 days, respectively, in the maize area. In the soybean area, 24% of the glyphosate was degraded to AMPA. In the maize area, it was only 5%. AMPA half-life and DT90 were 54.7 and 182 days, respectively, in the soybean area, and 71.0 and 236 days, respectively, in the maize area. Glyphosate and AMPA contents were 1.1-17.5 times higher in water-eroded sediment than in soil. We conclude that AMPA persists and may accumulate in soil, whereas both glyphosate and AMPA are prone to off-site transport with water erosion, representing a contamination risk for surface waters and adjacent fields.

Glyphosate and atrazine in rainfall and soils in agroproductive areas of the pampas region in Argentina

The presence in the atmosphere of glyphosate (GLP) and atrazine (ATZ) was investigated-those pesticides dominating the market in Argentina-through rain, as the main climatic phenomenon associated with wet deposition, both through analyzing source-receptor relationships with soil along with the climatic influences that may condition that transport and through estimating the annual deposition on the surface of the Argentine pampas. Rainwater samples (n = 112) were collected throughout each rainfall in urban areas of the pampas having different degrees of land use and with extensive crop production plus subsurface-soil samples (n = 58) from the relevant periurban sites. The herbicides-analyzed by liquid-chromatography-mass-spectrometry-were detected in >80% of the rain samples at median-to-maximum concentrations of 1.24-67.3 μg·L^-1 (GLP) and 0.22-26.9 μg·L^-1(ATZ), while aminomethylphosphonic acid (AMPA) was detected at 34% (0.75-7.91 μg·L^-1). In soils, GLP was more frequently registered (41%; 102-323 μg·kg^-1) followed by ATZ (32%; 7-66 μg·kg^-1) and then AMPA (22%; 223-732 μg·kg^-1). The maximum GLP concentrations quantified in rainwater exceeded the previously reported levels for the USA and Canada. No associations were observed between soil and rainwater concentrations in the same monitoring areas-despite the soil's action as a source, as evidenced through the AMPA present in rainwater. Median GLP concentrations were significantly associated with isohyets, in an increasing gradient from the east to the west-as such in an inverse pattern to that of the annual rainfall volumes; whereas ATZ-rainwater levels exhibited no characteristic spatial configuration. The estimated annual deposition of GLP by rainfall indicated that more than onc source of a herbicide can lead to its presence in the atmosphere and points out the relevance of rainfall's contribution to the surface levels of a pollutant.

A simple and rapid direct injection method for the determination of glyphosate and AMPA in environmental water samples

Glyphosate is currently the most widely used herbicide in the world, yet screening of environmental waters for this chemical is limited by the need for specialized derivatization and measurement methods that can be tedious and time-consuming. In this work, we present a novel method for the detection and quantification at trace levels of glyphosate and aminomethylphosphonic acid (AMPA) in environmental water samples. The detection and quantification of the analytes was performed by liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS). Chromatographic separation was achieved with an ion-exchange column and a pH-gradient elution of a solution of ammonium hydroxide and ammonium acetate. The limit of detection for glyphosate and AMPA was 0.25 μg L^-1 and the limit of quantification was 0.5 μg L^-1with a 20-μL injection. The method was used to investigate the levels of glyphosate and AMPA in surface water samples from the Yarra River catchment area and urban constructed stormwater wetlands. The results indicate that at the time of sampling, no glyphosate or AMPA was present in the samples from the Yarra River catchment area (n = 10). However, glyphosate was detected above the limit of quantification in 33% of the wetland samples (n = 12), with concentrations ranging from 1.95 to 2.96 μg L^-1. Similarly, AMPA was quantified in 83% of the wetland samples, with concentrations ranging from 0.55 to 2.42 μg L^-1. To our knowledge, this is the first report of a pH-gradient LC-MS/MS method for glyphosate and AMPA analysis at ultratrace levels, with minimal sample processing, avoiding costly, time-consuming derivatization and preconcentration steps. Graphical abstract ᅟ.

Soil microbial communities and glyphosate decay in soils with different herbicide application history

This study evaluates the glyphosate dissipation under field conditions in three types of soil, and aims to determine the importance of the following factors in the environmental persistence of herbicide: i) soil bacterial communities, ii) soil physicochemical properties, iii) previous exposure to the herbicide. A soil without previous record of GP application (P0) and two agricultural soils, with 5 and >10years of GP exposure (A5 and A10) were subjected to the application of glyphosate at doses of 3mg·kg-1. The concentration of GP and AMPA was determined over time and the dynamics of soil bacterial communities was evaluated using 16S ARN ribosomal gene amplicon-sequencing. The GP exposure history affected the rate but not the extent of GP biodegradation. The herbicide was degraded rapidly, but P0 soil showed a dissipation rate significantly lower than soils with agricultural history. In P0 soil, a significant increase in the relative abundance of Bacteroidetes was observed in response to herbicide application. More generally, all soils displayed shifts in bacterial community structure, which nevertheless could not be clearly associated to glyphosate dissipation, suggesting the presence of redundant bacteria populations of potential degraders. Yet the application of the herbicide prompted a partial disruption of the bacterial association network of unexposed soil. On the other hand, higher values of linear (Kd) and nonlinear (Kf) sorption coefficient in P0 point to the relevance of cation exchange capacity (CEC), clay and organic matter to the capacity of soil to adsorb the herbicide, suggesting that bioavailability was a key factor for the persistence of GP and AMPA. These results contribute to understand the relationship between bacterial taxa exposed to the herbicide, and the importance of soil properties as predictors of the possible rate of degradation and persistence of glyphosate in soil.

Kinetic study on biodegradation of glyphosate with unacclimated activated sludge

This article is concerned with the study of biodegradation of an organophosphorus herbicide (glyphosate) using unacclimated activated sludge. Glyphosate at different concentrations (0.1, 0.5, 1, 2 and 5 g/L) was tested for cellular growth. On the other hand, the effect of glyphosate on its own biodegradation was studied by evaluating the fittings of different kinetic models (Andrews, Aiba et al., Han and Levenspiel, Luong, Tessier, Webb, Tseng and Wayman, Yano and Koga). According to the obtained results, the activated sludge was able to use glyphosate as the sole carbon source; however, 2 and 5 g/L glyphosate seemed to inhibit cellular growth. Moreover, glyphosate at initial concentrations of 0.1, 0.5 and 1 g/L was completely degraded within 4, 13 and 18 h of incubation, respectively. Yano and Koga model was the best-fit model (R2 = 0.999, F = 173,106 and P = 0.000006).

Glyphosate affects the secretion of regulators of uterine contractions in cows while it does not directly impair the motoric function of myometrium in vitro

The effects of pure glyphosate and its most popular product (brand name: Roundup) on the secretion of hormones involved in the regulation of myometrial contractions as well as their direct effects on myometrial contractions were examined. Myometrial strips as well as uterine and ovarian cells were taken from cows during the oestrous cycle and they were treated with both compounds at concentrations from their environmental range. Glyphosate stimulated the secretion of oestradiol from granulosa cells while both herbicides increased and decreased oxytocin (OT) and progesterone secretion from luteal cells respectively. However only Roundup stimulated mRNA expression of the precursor of OT. Both compounds decreased the secretion of prostaglandins from endometrial cells while they exerted no effect on the basal and OT-stimulated force of myometrial contractions. The studied herbicides did not directly impair the motoric function of the myometrium. However our data indicate the potential of these compounds to disturb the secretory functions of the ovaries and uterus which can lead to the deregulation of uterine contractions and to the impairment of fertilisation or to difficulties in the maintenance of gestation.

Non-point source pollution of glyphosate and AMPA in a rural basin from the southeast Pampas, Argentina

We measured the occurrence and seasonal variations of glyphosate and its metabolite, aminomethylphosphonic acid (AMPA), in different environmental compartments within the limits of an agricultural basin. This topic is of high relevance since glyphosate is the most applied pesticide in agricultural systems worldwide. We were able to quantify the seasonal variations of glyphosate that result mainly from endo-drift inputs, that is, from direct spraying either onto genetically modified (GM) crops (i.e., soybean and maize) or onto weeds in no-till practices. We found that both glyphosate and AMPA accumulate in soil, but the metabolite accumulates to a greater extent due to its higher persistence. Knowing that glyphosate and AMPA were present in soils (> 93% of detection for both compounds), we aimed to study the dispersion to other environmental compartments (surface water, stream sediments, and groundwater), in order to establish the degree of non-point source pollution. Also, we assessed the relationship between the water-table depth and glyphosate and AMPA levels in groundwater. All of the studied compartments had variable levels of glyphosate and AMPA. The highest frequency of detections was found in the stream sediments samples (glyphosate 95%, AMPA 100%), followed by surface water (glyphosate 28%, AMPA 50%) and then groundwater (glyphosate 24%, AMPA 33%). Despite glyphosate being considered a molecule with low vertical mobility in soils, we found that its detection in groundwater was strongly associated with the month where glyphosate concentration in soil was the highest. However, we did not find a direct relation between groundwater table depth and glyphosate or AMPA detections. This is the first simultaneous study of glyphosate and AMPA seasonal variations in soil, groundwater, surface water, and sediments within a rural basin.

Distribution of glyphosate and aminomethylphosphonic acid (AMPA) in agricultural topsoils of the European Union

Approval for glyphosate-based herbicides in the European Union (EU) is under intense debate due to concern about their effects on the environment and human health. The occurrence of glyphosate residues in European water bodies is rather well documented whereas only few, fragmented and outdated information is available for European soils. We provide the first large-scale assessment of distribution (occurrence and concentrations) of glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) in EU agricultural topsoils, and estimate their potential spreading by wind and water erosion. Glyphosate and/or AMPA were present in 45% of the topsoils collected, originating from eleven countries and six crop systems, with a maximum concentration of 2mgkg^-1. Several glyphosate and AMPA hotspots were identified across the EU. Soil loss rates (obtained from recently derived European maps) were used to estimate the potential export of glyphosate and AMPA by wind and water erosion. The estimated exports, result of a conceptually simple model, clearly indicate that particulate transport can contribute to human and environmental exposure to herbicide residues. Residue threshold values in soils are urgently needed to define potential risks for soil health and off site effects related to export by wind and water erosion.

Spatial glyphosate and AMPA redistribution on the soil surface driven by sediment transport processes - A flume experiment

This study investigates the influence of small-scale sediment transport on glyphosate and AMPA redistribution on the soil surface and on their off-site transport during water erosion events. Both a smooth surface (T1) and a surface with "seeding lines on the contour" (T2) were tested in a rainfall simulation experiment using soil flumes (1 × 0.5 m) with a 5% slope. A dose of 178 mg m-2 of a glyphosate-based formulation (CLINIC®) was applied on the upper 0.2 m of the flumes. Four 15-min rainfall events (RE) with 30-min interval in between and a total rainfall intensity of 30 mm h-1 were applied. Runoff samples were collected after each RE in a collector at the flume outlet. At the end of the four REs, soil and sediment samples were collected in the application area and in four 20 cm-segments downslope of the application area. Samples were collected according to the following visually distinguished soil surface groups: light sedimentation (LS), dark sedimentation (DS), background and aggregates. Results showed that runoff, suspended sediment and associated glyphosate and AMPA off-site transport were significantly lower in T2 than in T1. Glyphosate and AMPA off-site deposition was higher for T2 than for T1, and their contents on the soil surface decreased with increasing distance from the application area for all soil surface groups and in both treatments. The LS and DS groups presented the highest glyphosate and AMPA contents, but the background group contributed the most to the downslope off-site deposition. Glyphosate and AMPA off-target particle-bound transport was 9.4% (T1) and 17.8% (T2) of the applied amount, while water-dissolved transport was 2.8% (T1) and 0.5% (T2). Particle size and organic matter influenced the mobility of glyphosate and AMPA to off-target areas. These results indicate that the pollution risk of terrestrial and aquatic environments through runoff and deposition can be considerable.