Glyphosate and AMPA of agricultural soil, surface water, groundwater and sediments in areas prevalent with chronic kidney disease of unknown etiology, Sri Lanka

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.

Effects of herbicides and fertilization on biofilms of Pampean lotic systems: A microcosm study

We experimentally assessed the impact of the application of herbicides and fertilizers derived from agricultural activity through the individual and simultaneous addition of glyphosate, atrazine, and nutrients (nitrogen 'N' and phosphorus 'P') on the biofilm community and their resilience when the experimental factors were removed. We hypothesize that i) the presence of agrochemicals negatively affects the biofilm community leading to the simplification of the community structure; ii) the individual or simultaneous addition of herbicides and nutrients produces differential responses in the biofilm; and iii) the degree of biofilm recovery differs according to the treatment applied. Environmentally relevant concentrations of glyphosate (0.7 mgL-1), atrazine (44 μgL-1), phosphorus (1 mg P L-1 [KH2PO4]), and nitrogen (3 mg N L-1[NaNO3]) were used. Chlorophyll a, ash-free dry weight, abundance of main biofilm groups and nutrient contents in biofilm were analyzed. At initial exposure time, all treatments were dominated by Cyanobacteria; through the exposure period, it was observed a progressive replacement by Bacillariophyceae. This replacement occurred on day 3 for the control and was differentially delayed in all herbicides and/or nutrient treatments in which the abundance of cyanobacteria remains significant yet in T5. A significant correlation was observed between the abundance of cyanobacteria and the concentration of atrazine, suggesting that this group is less sensitive than diatoms. The presence of agrochemicals exerted differential effects on the different algal groups. Herbicides contributed to phosphorus and nitrogen inputs. The most frequently observed interactions between experimental factors (nutrients and herbicides) was additivity excepting for species richness (antagonistic effect). In the final recovery time, no significant differences were found between the treatments and the control in most of the evaluated parameters, evincing the resilience of the community.

Association of urine glyphosate levels with renal injury biomarkers in children living close to major vegetable-producing regions in China

Glyphosate (GLY)-based herbicides exposure contributes to renal dysfunction in experimental conditions, but the effects on humans are rarely reported. Biomonitoring is practically relevant for evaluating the association of urine GLY levels and renal damage in children living close to vegetable-cultivating regions. In this study, we collected the first-morning void urine samples of 239 healthy children (aged 3-12, 48.12 % boys) living near major vegetable-producing regions in March-May and August 2023 in Shandong Province, China. Urine levels of GLY and kidney injury-associated biomarkers were determined using ELISA kits to assess their correlation. GLY was detected in 92.05 % of urine samples (220 out of 239 participants) and the geometric concentration (GM) was 7.429 μg/L (range: 0.625 to 38.267 μg/L). Binary logistic regression and multivariate regression analysis revealed GLY detectability and levels positively correlated with home ventilation and self-producing vegetable intake of the subjects, as well as sampling periods. Moreover, a statistically significant concentration association with urine GLY was found for kidney injury-associated biomarkers (NGAL and KIM-1) (R2 = 0.923 and 0.855, respectively). Additionally, risk assessment revealed that the maximum value of probable daily intake was 0.150 mg/kg bw/day, accounting for 30.1 % of the established Acceptable Daily Intake of GLY. This study unveils a positive correlation between continuous GLY-based herbicide exposure and renal injury biomarkers of children. A large-scale epidemiological study is warranted for comprehensively assessing the effects of GLY-based herbicides on kidney function of the entire public.

Transcriptomic and behavioral analyses reveal unique target tissues and molecular pathways associated with embryonic exposure to low level glyphosate and metal mixtures in zebrafish

Investigation of developmental molecular events following exposure to environmentally relevant agrochemical mixtures is critical to predicting their potential long-term ecological and human health risks. Here, we sought to uncover transcriptomic changes during zebrafish (Danio rerio) embryonic development following exposure to glyphosate and co-exposure to metals. Glyphosate is widely used globally with an allowable drinking water limit of 700 ppb. We examined effects of glyphosate (10 ppb) alone and when co-exposed to a metal mixture containing low levels of arsenic (4 ppb), lead (5 ppb), cadmium (2 ppb), and vanadium (15 ppb). This mixture was derived based on behavioral and morphological toxicity findings and environmentally relevant concentrations found in agricultural regions where glyphosate and metals are ubiquitously present. Gene expression patterns coupled to a single-cell transcriptomic dataset revealed that developmental exposure (28-72 h post fertilization) to glyphosate dysregulates expression of developmental genes specific to the central nervous system. Subsequent studies indicated significant suppression of larval zebrafish movement with 10 ppb glyphosate exposure. Studies with glyphosate + metals mixture and metals mixture alone showed unique developmental transcriptomic patterns and behavioral changes compared to glyphosate exposure alone. However, some outcomes (e.g., changes in expression of genes involved in epigenetic regulation and extracellular matrix patterning) were common across all three exposures compared to the control. Notably, glyphosate + metals co-exposure distinctly suppresses lysosomal transcripts and targets renal developmental genes. While further studies are required to uncover the precise nature of the interactions between glyphosate and metals, our study shows that glyphosate at very low levels is a behavioral and neurotoxicant that changes when metals are present. Given this herbicide affects distinctive physiological processes, including renal development and lysosomal dysregulation when co-exposed with metals, we conclude that environmental cation levels should be considered in glyphosate toxicity and risk assessment.

Systemic Analysis of Glyphosate Impact on Environment and Human Health

With a growing global population, agricultural scientists are focusing on crop production management and the creation of new strategies for a higher agricultural output. However, the growth of undesirable plants besides the primary crop poses a significant challenge in agriculture, necessitating the massive application of herbicides to eradicate this problem. Several synthetic herbicides are widely utilized, with glyphosate emerging as a potential molecule for solving this emerging issue; however, it has several environmental and health consequences. Several weed species have evolved resistance to this herbicide, therefore lowering agricultural yield. The persistence of glyphosate residue in the environment, such as in water and soil systems, is due to the misuse of glyphosate in agricultural regions, which causes its percolation into groundwater via the vertical soil profile. As a result, it endangers many nontarget organisms existing in the natural environment, which comprises both soil and water. The current Review aims to provide a systemic analysis of glyphosate, its various effects on the environment, its subsequent impact on human health and animals, which will lead us toward a better understanding of the issues about herbicide usage and aid in managing it wisely, as in the near the future glyphosate market is aiming for a positive forecast until 2035.

Occurrence, multiphase partitioning, drivers, and ecological risks of current-use herbicides in a river basin dominated by rice-vegetable rotations in tropical China

Rice-vegetable rotation practices prevail in subtropical and tropical agriculture worldwide, with applications of current-use herbicides (CUHs) vital for nontarget plant control. After application, CUHs migrate to environmental compartments, where the occurrence, fate, and ecological risks have not been well characterized. To further understand the occurrence and multiphase partitioning, as well as to evaluate potential drivers and mixture risks in environmental compartments, we analyzed 11 CUHs in 576 samples from 36 rice-vegetable rotations in Nandu River basin, Hainan, China. Samples included soil, water, suspended particulate matter, and sediment collected during both rice and vegetable planting periods. The CUH concentrations varied across environmental compartments, but with high levels of glyphosate and aminomethylphosphonic acid organophosphorus herbicides (OPHs) frequently detected, accounting for 82.3 % to 99.0 % in environmental compartments. Phenoxy acid (PAA) and chloroacetanilide (ANH) herbicides were detected at lower frequencies. Spatiotemporal variation was significantly different among OPHs, ANHs, and PAAs, with geographic and crop-related patterns most evident for CUHs rather than OPHs. Structural equation model, redundancy, and boosted regression tree analyses indicated environmental compartment properties (pH, organic matter, and Fe/Al oxides), crop type, and wet/dry climate were important drivers of spatiotemporal patterns. Fugacity ratios indicated multiphase partitioning and transport of CUHs differed in rice and vegetable planting periods. A new assessment framework based on species-sensitive distributions and environmental compartment weight index indicated unacceptable risks of CUHs (risk quotient >1 in >50 % of sites), with most risks from OPHs (10.5 % to 98.0 %) and butachlor, acetochlor, and 2,4-dichlorophenoxyacetic acid. Risk hot spots were identified as the soil, the central region, and the vegetable planting period, potentially threatening nontarget organisms (e.g., Lemna minor, Glomus intraradices, and Apis mellifera). This study provides a new risk assessment framework and demonstrates the domination of OPHs in CUH contamination and risks in the tropics, thus helping guide policymakers and stakeholders on herbicide management.

Kinetics of glyphosate and aminomethylphosphonic acid sorption onto montmorillonite clays in soil and their translocation to genetically modified corn

The co-occurrence of glyphosate (GLP) and aminomethylphosphonic acid (AMPA) in contaminated water, soil, sediment and plants is a cause for concern due to potential threats to the ecosystem and human health. A major route of exposure is through contact with contaminated soil and consumption of crops containing GLP and AMPA residues. However, clay-based sorption strategies for mixtures of GLP and AMPA in soil, plants and garden produce have been very limited. In this study, in vitro soil and in vivo genetically modified corn models were used to establish the proof of concept that the inclusion of clay sorbents in contaminated soils will reduce the bioavailability of GLP and AMPA in soils and their adverse effects on plant growth. Effects of chemical concentration (1-10 mg/kg), sorbent dose (0.5%-3% in soil and 0.5%-1% in plants) and duration (up to 28 days) on sorption kinetics were studied. The time course results showed a continuous GLP degradation to AMPA. The inclusion of calcium montmorillonite (CM) and acid processed montmorillonite (APM) clays at all doses significantly and consistently reduced the bioavailability of both chemicals from soils to plant roots and leaves in a dose- and time-dependent manner without detectable dissociation. Plants treated with 0.5% and 1% APM inclusion showed the highest growth rate (p ≤ 0.05) and lowest chemical bioavailability with up to 76% reduction in roots and 57% reduction in leaves. Results indicated that montmorillonite clays could be added as soil supplements to reduce hazardous mixtures of GLP and AMPA in soils and plants.

Underestimation of glyphosate intake by the methods currently used by regulatory agencies

The acceptable daily intake (ADI) is an estimate of the amount of a substance in food or beverages that can be consumed daily over a lifetime without presenting an appreciable risk to health. To assess the risk of ingesting glyphosate, regulatory agencies compare glyphosate daily intake to ADI. Based on published data on urine glyphosate levels measured according to known quantities of ingested glyphosate, our objectives were to test the robustness of the mathematical model currently used to calculate glyphosate daily intake, and to propose alternative models based on urinary excretion kinetics. Our results support that the quantity of ingested glyphosate is systematically underestimated by the model currently used by regulatory agencies, whereas the other models evaluated showed better estimations, with differences according to gender. Our results also show a great variability between individuals, leading to some uncertainties notably with regards to the ADI, and further support that glyphosate excretion varies significantly among individuals who follow a similar dosing regimen. In conclusion, our study highlights the lack of reliability of assessment processes carried out by regulatory agencies for glyphosate in particular, and pesticides in general, and questions the relevance of such processes supposed to safeguard human health and the environment.

Occurrence and exposure assessment of glyphosate in the environment and its impact on human beings

Glyphosate is a broad-spectrum and one of the most widely used herbicides in the world, which has led to its high environmental dissemination. In 2015, the International Agency for Research on Cancer stated that glyphosate was a probable human carcinogen. Since then, several studies have provided new data about the environmental exposure of glyphosate and its consequences on human health. Thus, the carcinogenic effects of glyphosate are still under debate. This work aimed to review glyphosate occurrence and exposure since 2015 up to date, considering studies associated with either environmental or occupational exposure and the epidemiological assessment of cancer risk in humans. These articles showed that herbicide residues were detectable in all spheres of the earth and studies on the population showed an increase in the concentration of glyphosate in biofluids, both in the general population and in the occupationally exposed population. However, the epidemiological studies under review provided limited evidence for the carcinogenicity of glyphosate, which was consistent with the International Agency for Research on Cancer classification as a probable carcinogen.

Universal Method Based on Layer-by-Layer Assembly for Aptamer-Based Sensors for Small-Molecule Detection

Development of a fast and accurate pesticide analysis system is a challenging task, as a large amount of commonly used pesticide has negative effects on humans' health. Detection of pesticide residues is crucial for food safety management and environmental protection. Aptamers─short single-stranded oligonucleotides (RNA or DNA) selected by aptamer selection method SELEX─can selectively bind to their target pesticide molecules with high affinity. Thus, in the present study, we developed an electrochemical biosensor based on aptamers to detect the commonly used pesticide, glyphosate. Carbon fibers were used as the platform to assemble polyelectrolyte layers with the incorporated aptamers selectively binding with glyphosate molecules for electrochemical detection. The best limit of detection of 0.3 μM was achieved at open-circuit potential measurements, which is comparable to the current need in detection of glyphosate. The developed method can be implemented into existing systems for the determination of pesticides on farms to control residual concentrations of glyphosate in soil and water.

Methods and Strategies for Biomonitoring in Occupational Exposure to Plant Protection Products Containing Glyphosate

Glyphosate, and the ever growing reliance on its use in agriculture, has been a point of contention for many years. There have been debates regarding the risk and safety of using glyphosate-based herbicides as well as the effects of occupational, accidental, or systematic. Although there have been a number of studies conducted, the biomonitoring of glyphosate poses a series of challenges. Researchers attempting to determine the occupational exposure face questions regarding the most appropriate analytical techniques and sampling procedures. The present review aims to summarize and synthetize the analytical methodologies available and suitable for the purpose of glyphosate biomonitoring studies as well as discuss the advantages and disadvantages of each analytical technique, from the most modern to more well-established and older ones. The most relevant publications that have described analytical methods and published within the last 12 years were studied. Methods were compared, and the advantages and disadvantages of each methods were discussed. A total of 35 manuscripts describing analytical methods for glyphosate determination were summarized and discussed, with the most relevant one being compared. For methods that were not intended for biological samples, we discussed if they could be used for biomonitoring and approaches to adapt these methods for this purpose.

Fluorescence characteristics and source analysis of DOM in groundwater during the wet season in the CKDu zone of North Central Province, Sri Lanka

The dissolved organic matter (DOM) should be purified for safe drinking water due to disinfection by-products (DBPs) produced by disinfectants reaction with DOM. Current research on groundwater in the chronic kidney disease with unknown etiology (CKDu) zone of the North Central Province (NCP) in Sri Lanka has focused mainly on aquatic chemistry, with limited attention paid to the spatial distribution, compositional sources and factors of DOM. Therefore, the structure, composition, source and spatial distribution of the DOM of two kinds of groundwater samples collected from dug well and tube well in the NCP during the wet season were determined, compared and analyzed by analytical tools such as parallel factor analysis (PARAFAC). Results show that the average concentrations of TOC in these two groundwater samples are generally higher than 5.0 mg/L, and the concentration of TOC in the groundwater of the shallow weathered aquifer is higher than that of the deep hard rock aquifer, while its distribution of the two aquifers are on contrary. The DOM in the dug well has three types and four components, including humus-like component C1 (33.36%) and C2 (38.60%), protein-like component C3 (13.09%) and heterogeneous organic component C4 (14.95%). In the tube well, two types and two components of the DOM are determined, including humus-like component CⅠ (69.80%) widely existing in natural water and soluble microbial by-product CⅡ (30.20%) produced by microbial community activities. In the dug well, DOM is mainly exogenous input, the higher ion concentration in water affected the fluorescence intensity of humus and protein components. And in the tube well, DOM has obvious endogenous characteristics, and higher pH value may inhibit the production of protein like fluorescent substances to a certain extent.

Ecotoxicological relevance of glyphosate and flazasulfuron to soil habitat and retention functions - Single vs combined exposures

Glyphosate (GLY) and flazasulfuron (FLA) are two non-selective herbicides commonly applied together. However, research focused on their single and combined ecotoxicological impacts towards non-target organisms is still inconclusive. Therefore, this study aimed to test their single effects on soil's habitat and retention functions, and to unravel their combined impacts to earthworms and terrestrial plants. For this, ecotoxicological assays were performed with plants (Medicago sativa), oligochaetes (Eisenia fetida) and collembola (Folsomia candida). Soil elutriates were also prepared and tested in macrophytes (Lemna minor) and microalgae (Raphidocelis subcapitata). FLA (82-413 µg kg^-1) reduced earthworms' and collembola's reproduction and severely impaired M. sativa growth, being much more toxic than GLY (up to 30 mg kg^-1). In fact, the latter only affected plant growth (≥ 9 mg kg^-1) and earthworms (≥ 13 mg kg^-1), especially at high concentrations, with no effects on collembola. Moreover, only elutriates from FLA-contaminated soils significantly impacted L. minor and R. sucapitata. The experiments revealed that the co-exposure to GLY and FLA enhanced the toxic effects of contaminated soils not only on plants but also on earthworms'. However, such increase in toxicity was dependent on GLY residual concentrations in soils. Overall, this work underpins that herbicides risk assessment should consider herbicides co-exposures, since the evaluation of single exposures is not representative of current phytosanitary practices and of the potential effects under field conditions, where residues of different compounds may persist in soils.

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

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

Environmental behaviour of a pesticide metabolite, the AMPA. Sequestration of Ca2+, Mg2+, Cu2+, Zn2+ and Al3. CHEMOSPHERE 2022;306:135535. [PMID: 35792217 DOI: 10.1016/j.chemosphere.2022.135535]

The chelating and sequestering ability of a glyphosate metabolite, the aminomethylphosphonic acid (AMPA) towards bi- and trivalent metal cations, such as Ca²⁺, Mg²⁺, Zn²⁺, Cu²⁺ and Al³⁺, were investigated in aqueous solutions of NaCl, in an ionic strength range of 0.1 ≤ I/mol dm^-3 ≤ 1.0 and at constant temperature of T = 298.15 ± 0.15 K. The investigations on the acid-base properties and complexing ability were performed, by means of potentiometry, in conditions of different c_M:c_AMPA molar ratios and pH values. The formation of insoluble species was experimentally observed in the Mⁿ⁺/AMPA^2- systems, and the solid phases were characterized by means of X-Ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and InfraRed Attenuated Total Reflection spectroscopy (IR-ATR). The dependence on ionic strength of the stability constants of the Mⁿ⁺/AMPA^2- complexes species, determined at different ionic strengths, was modelled by the Debye-Hückel type equation. The sequestering ability of AMPA toward the investigated metal cations was evaluated by pL_0.5 parameter.

Effects of the herbicide glyphosate on fish from embryos to adults: a review addressing behavior patterns and mechanisms behind them

The use of agrochemicals has grown in recent years following the increase in agricultural productivity, to eliminate weeds that can compromise crop yields. The intensive use of these products combined with the lack of treatment of agricultural wastewater is causing contamination of the natural environments, especially the aquatics. Glyphosate [N-(phosphonomethyl) glycine] is the most commonly used herbicide in agriculture worldwide. Studies have shown that this compound is toxic to a variety of fish species at the concentrations of environmental relevance. Glyphosate-based herbicides can affect fish biochemical, physiological, endocrine, and behavioral pathways. Changes in behaviors such as foraging, escaping from predators, and courtship can compromise the survival of species and even communities. The behavior patterns of fish has been shown to be a sensitive tool for risk assessment. In this sense, this review summarizes and discusses the toxic effects of glyphosate and its formulations on the behavior of fish in different life stages. Additionally, behavioral impairments were associated with other negative effects of glyphosate such as energy imbalance, stress responses, AChE inhibition, and physiological and endocrine disturbances, which are evidenced and described in the literature. Graphical abstract.

Capturing In Situ Glyphosate (De)sorption Kinetics in Floodplain Aquifer Sediment Columns: Geophysical Measurements and Reactive Transport Modeling

Glyphosate, an ionizable organic herbicide, is frequently detected in soils and groundwater globally despite its strong retention via sorption. Understanding its apparent mobility hinges on our ability to quantify its system-specific sorption behavior, hindered by its affinity to adsorb onto sediments, yielding very low aqueous concentrations. Here, we present findings from a saturated flow-through column experiment in which we monitored glyphosate sorption onto a natural calcareous aquifer sediment, using the noninvasive geophysical method spectral induced polarization (SIP). Our kinetic sorption reactive transport model predicted the strong nonlinear reversible retention of glyphosate and reproduced the spatial profile of retained glyphosate in the sediment, with a measured maximum of 0.06 mg g^-1. The strong contribution of sorption to pore fluid conduction masked the expected variations in imaginary conductivity, σ″. However, time constants derived from a Cole-Cole model matched the timing and spatial distribution of model-predicted sorbed concentration changes, increasing from 0.8 × 10^-3 to 1.7 × 10^-3 s with an increase in sorbed glyphosate of 0.1 mg g^-1. Thus, glyphosate sorption modified the surface charging properties of the sediment proportional to the solid-bound concentrations. Our findings link SIP signal variations to sorption dynamics and provide a framework for improved monitoring of charged organic contaminants in natural sediments.

Overview of Environmental and Health Effects Related to Glyphosate Usage

Since the introduction of glyphosate (N-(phosphomethyl) glycine) in 1974, it has been the most used nonselective and broad-spectrum herbicide around the world. The widespread use of glyphosate and glyphosate-based herbicides is due to their low-cost efficiency in killing weeds, their rapid absorption by plants, and the general mistaken perception of their low toxicity to the environment and living organisms. As a consequence of the intensive use and accumulation of glyphosate and its derivatives on environmental sources, major concerns about the harmful side effects of glyphosate and its metabolites on human, plant, and animal health, and for water and soil quality, are emerging. Glyphosate can reach water bodies by soil leaching, runoff, and sometimes by the direct application of some approved formulations. Moreover, glyphosate can reach nontarget plants by different mechanisms, such as spray application, release through the tissue of treated plants, and dead tissue from weeds. As a consequence of this nontarget exposure, glyphosate residues are being detected in the food chains of diverse products, such as bread, cereal products, wheat, vegetable oil, fruit juice, beer, wine, honey, eggs, and others. The World Health Organization reclassified glyphosate as probably carcinogenic to humans in 2015 by the IARC. Thus, many review articles concerning different glyphosate-related aspects have been published recently. The risks, disagreements, and concerns regarding glyphosate usage have led to a general controversy about whether glyphosate should be banned, restricted, or promoted. Thus, this review article makes an overview of the basis for scientists, regulatory agencies, and the public in general, with consideration to the facts on and recommendations for the future of glyphosate usage.

Urinary Levels of Sirtuin-1, π-Glutathione S-Transferase, and Mitochondrial DNA in Maize Farmer Occupationally Exposed to Herbicide

Epidemiologic studies have suggested an association between agrochemical exposure and risk of renal injury. Farmers face great risks to developing adverse effects. The most appropriate biomarker related to renal injury needs to be developed to encounter earlier detection. We aim to study the association between early renal biomarker and occupational herbicide exposure in maize farmers, Thailand. Sixty-four farmers were recruited and interviewed concerning demographic data, herbicide usage, and protective behavior. Two spot urines before (pre-work task) and after (post-work task) herbicide spraying were collected. To estimate the intensity of exposure, the cumulative herbicide exposure intensity index (cumulative EII) was also calculated from activities on the farm, type of personal protective equipment (PPE) use, as well as duration and frequency of exposure. Four candidate renal biomarkers including π-GST, sirtuin-1, mitochondrial DNA (mtDNA) were measured. Most subjects were male and mostly sprayed three herbicides including glyphosate-based herbicides (GBH), paraquat, and 2,4-dichlorophenoxyacetic acid (2,4-D). A type of activity in farm was mixing and spraying herbicide. Our finding demonstrated no statistical significance of all biomarker levels between pre- and post-work task urine. To compare between single and cocktail use of herbicide, there was no statistical difference in all biomarker levels between pre- and post-work task urine. However, the urinary mtDNA seems to be increased in post-work task urine. Moreover, the cumulative EII was strongly associated with change in mtDNA content in both ND-1 and COX-3 gene. The possibility of urinary mtDNA as a valuable biomarker was promising as a noninvasive benchmark for early detection of the risk of developing renal injury from herbicide exposure.

A review of molecular mechanisms linked to potential renal injury agents in tropical rural farming communities

The chronic kidney disease of unknown etiology (CKDu) is a global health concern primarily impacting tropical farming communities. Although the precise etiology is debated, CKDu is associated with environmental exposures including heat stress and chemical contaminants such as fluoride, heavy metals, and herbicide glyphosate. However, a comprehensive synthesis is lacking on molecular networks underpinning renal damage induced by these factors. Addressing this gap, here we present key molecular events associated with heat and chemical exposures. We identified that caspase activation and lipid peroxidation are common endpoints of glyphosate exposure, while vasopressin and polyol pathways are associated with heat stress and dehydration. Heavy metal exposure is shown to induce lipid peroxidation and endoplasmic reticulum stress from ROS activated MAPK, NFĸB, and caspase. Collectively, we identify that environmental exposure induced increased cellular oxidative stress as a common mechanism mediating renal cell inflammation, apoptosis, and necrosis, likely contributing to CKDu initiation and progression.

Quantifiable urine glyphosate levels detected in 99% of the French population, with higher values in men, in younger people, and in farmers

France is the first pesticide-consuming country in Europe. Glyphosate is the most used pesticide worldwide and glyphosate is detected in the general population of industrialized countries, with higher levels found in farmers and children. Little data was available concerning exposure in France. Our objective was to determine glyphosate levels in the French general population and to search for an association with seasons, biological features, lifestyle status, dietary habits, and occupational exposure. This study includes 6848 participants recruited between 2018 and 2020. Associated data include age, gender, location, employment status, and dietary information. Glyphosate was quantified by a single laboratory in first-void urine samples using ELISA. Our results support a general contamination of the French population, with glyphosate quantifiable in 99.8% of urine samples with a mean of 1.19 ng/ml + / - 0.84 after adjustment to body mass index (BMI). We confirm higher glyphosate levels in men and children. Our results support glyphosate contamination through food and water intake, as lower glyphosate levels are associated with dominant organic food intake and filtered water. Higher occupational exposure is confirmed in farmers and farmers working in wine-growing environment. Thus, our present results show a general contamination of the French population with glyphosate, and further contribute to the description of a widespread contamination in industrialized countries.

Groundwater-Based Drinking Water Supply in Sri Lanka: Status and Perspectives

Drinking water is largely from groundwater in Sri Lanka, so quality management is of great concern. In order to achieve the 6th goal of United Nations (UN) Sustainable Development Goals (SDG), more efforts are being undertaken to secure drinking water quality. In this paper, the current status, challenges and opportunities of groundwater quality management and improvement in Sri Lanka were reviewed and discussed, based on previous studies. There are Ca-HCO3 type, Ca–Mg-HCO3 type and Na–SO4–Cl type groundwater dominated in the wet zone, intermediate and the dry zone, respectively. Elevated levels of hardness, fluoride, DOC, and alkalinity, and salinity are reported in the groundwater in the dry zone controlled by geology and arid climate. Although groundwater in some regions contain significant levels of nitrates, arsenic, cadmium and lead, the majority remain at acceptable levels for drinking purposes. As for treatment technologies, existing membrane-based drinking water treatment technologies such as RO (Reverse Osmosis) stations can produce safe and clean drinking water to the community, but this has still a limited coverage. To achieve a safe drinking water supply for all, especially in rural communities of Sri Lanka under the 6th goal of the UN SDG, more efforts in building up the infrastructure and man power are needed to monitor and assess groundwater quality regularly so as to develop management strategies. Research and development can be directed towards more cost-effective water treatment technologies. Protection of groundwater from being polluted, and educational and awareness programs for the stakeholders are also essential tasks in the future.

Microbiomes and glyphosate biodegradation in edaphic and aquatic environments: recent issues and trends

Glyphosate (N-(phosphonomethyl)glycine) has emerged as the top-selling herbicide worldwide because of its versatility in controlling annual and perennial weeds and the extensive use of glyphosate-resistant crops. Concerns related to the widespread use of glyphosate and its ubiquitous presence in the environment has led to a large number of studies and reviews, which examined the toxicity and fate of glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA) in the environment. Because the biological breakdown of glyphosate is most likely the main elimination process, the biodegradation of glyphosate has also been the object of abundant experimental work. Importantly, glyphosate biodegradation in aquatic and soil ecosystems is affected not only by the composition and the activity of microbial communities, but also by the physical environment. However, the interplay between microbiomes and glyphosate biodegradation in edaphic and aquatic environments has rarely been considered before. The proposed minireview aims at filling this gap. We summarize the most recent work exploring glyphosate biodegradation in natural aquatic biofilms, the biological, chemical and physical factors and processes playing on the adsorption, transport and biodegradation of glyphosate at different levels of soil organization and under different agricultural managements, and its impact on soil microbial communities.

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.

Chronic kidney disease of unknown etiology in India: a comparative study with Mesoamerican and Sri Lankan nephropathy

Chronic kidney disease of unknown etiology [CKDu] is a condition characterized by decline in kidney function and is not associated with diabetic nephropathy or hypertensive nephropathy. In this review, we have done a detailed literature analysis on CKDu in India, and then had a comparison with that of Mesoamerica and Sri Lanka. In India, CKDu became the second most common type of CKD after diabetic nephropathy. Silica was seen in the groundwater of both India and Sri Lanka, whereas in Mesoamerica silica exposure through particulate matter was seen among CKDu communities. DDE is a common agrochemical seen in both India and Sri Lanka. The risk factors vary from region to region and it is important to categorize CKDu population based on the risk factors to avoid misinterpretation of the condition as non-CKDu category and to evade further complications. More studies have to be conducted to reveal the detailed pathophysiological mechanisms and its relation with irrational exploitation of environmental resources.

Glyphosate vs. Glyphosate-Based Herbicides Exposure: A Review on Their Toxicity

Glyphosate-based herbicide has been the first choice for weed management worldwide since the 1970s, mainly due to its efficacy and reported low toxicity, which contributed to its high acceptance. Many of the recent studies focus solely on the persistence of pesticides in soils, air, water or food products, or even on the degree of exposure of animals, since their potential hazards to human health have raised concerns. Given the unaware exposure of the general population to pesticides, and the absence of a significant number of studies on occupational hazards, new glyphosate-induced toxicity data obtained for both residual and acute doses should be analyzed and systematized. Additionally, recent studies also highlight the persistence and toxicity of both glyphosate metabolites and surfactants present in herbicide formulations. To renew or ban the use of glyphosate, recently published studies must be taken into account, aiming to define new levels of safety for exposure to herbicide, its metabolites, and the toxic excipients of its formulations. This review aims to provide an overview of recent publications (2010–present) on in vitro and in vivo studies aimed at verifying the animal toxicity induced by glyphosate, its metabolite aminomethylphosphonic acid (AMPA) and glyphosate-based formulations, evaluated in various experimental models. Apart from glyphosate-induced toxicity, recent data concerning the role of surfactants in the toxicity of glyphosate-based formulations are discussed.

A pyrene-based ratiometric probe for nanomolar level detection of glyphosate in food and environmental samples and its application for live-cell imaging

An in situ formed copper(ii)-complex is involved in analyzing glyphosate in real-life samples, such as crops, soil, water and biological fluids.

Glyphosate Use, Toxicity and Occurrence in Food

Glyphosate is a systemic, broad-spectrum and post-emergent herbicide. The use of glyphosate has grown in the last decades, and it is currently the most used herbicide worldwide. The rise of glyphosate consumption over the years also brought an increased concern about its possible toxicity and consequences for human health. However, a scientific community consensus does not exist at the present time, and glyphosate's safety and health consequences are controversial. Since glyphosate is mainly applied in fields and can persist several months in the soil, concerns have been raised about the impact that its presence in food can cause in humans. Therefore, this work aims to review the glyphosate use, toxicity and occurrence in diverse food samples, which, in certain cases, occurs at violative levels. The incidence of glyphosate at levels above those legally allowed and the suspected toxic effects of this compound raise awareness regarding public health.

Glyphosate concentrations in global freshwaters: are aquatic organisms at risk?

Glyphosate is the most used herbicide worldwide. Many studies have reported glyphosate risks to aquatic organisms of different trophic levels. Moreover, evidence suggests flaws in countries' legislation that may imply the non-protection of aquatic species exposed to glyphosate. Therefore, we aimed to investigate glyphosate concentrations in freshwater ecosystems worldwide based on a systematic literature review, to discuss the results considering each country's legislation, and to assess the relative tolerance and risk for aquatic species. Only articles providing in situ concentrations of glyphosate in freshwater systems were included in our study. In total, 73 articles met the inclusion criteria and were used in our analysis. The studies comprised freshwater ecosystems from 21 countries. Most countries evaluated (90%) did not have restrictive legislation for aquatic glyphosate concentrations, resulting in a potential non-protection of aquatic organisms. Glyphosate may pose a moderate to high risk in 95% of the countries investigated, reaching a maximum concentration of 105 mg L-1. Additionally, the risk analysis showed that glyphosate concentrations below 0.1 μg L-1 represent a low risk, whereas glyphosate concentrations above 1 μg L-1, which is below the limit established by some countries' legislation, represent a high risk to aquatic organisms. Therefore, we strongly recommend a revision of the countries' legislation for glyphosate concentration in freshwater systems.

Glyphosate Herbicide: Reproductive Outcomes and Multigenerational Effects

Glyphosate base herbicides (GBHs) are the most widely applied pesticides in the world and are mainly used in association with GBH-tolerant crop varieties. Indiscriminate and negligent use of GBHs has promoted the emergence of glyphosate resistant weeds, and consequently the rise in the use of these herbicides. Glyphosate, the active ingredient of all GBHs, is combined with other chemicals known as co-formulants that enhance the herbicide action. Nowadays, the safety of glyphosate and its formulations remain to be a controversial issue, as evidence is not conclusive whether the adverse effects are caused by GBH or glyphosate, and little is known about the contribution of co-formulants to the toxicity of herbicides. Currently, alarmingly increased levels of glyphosate have been detected in different environmental matrixes and in foodstuff, becoming an issue of social concern. Some in vitro and in vivo studies have shown that glyphosate and its formulations exhibit estrogen-like properties, and growing evidence has indicated they may disrupt normal endocrine function, with adverse consequences for reproductive health. Moreover, multigenerational effects have been reported and epigenetic mechanisms have been proved to be involved in the alterations induced by the herbicide. In this review, we provide an overview of: i) the routes and levels of human exposure to GBHs, ii) the potential estrogenic effects of glyphosate and GBHs in cell culture and animal models, iii) their long-term effects on female fertility and mechanisms of action, and iv) the consequences on health of successive generations.

Glyphosate Interaction with eEF1α1 Indicates Altered Protein Synthesis: Evidence for Reduced Spermatogenesis and Cytostatic Effect

The broad-spectrum herbicide, glyphosate, is considered safe for animals because it selectively affects the shikimate pathway that is specific to plants and microorganisms. We sought a previously unknown mechanism to explain the concerns that glyphosate exposure can negatively affect animals, including humans. Computer modeling showed a probable interaction between glyphosate and eukaryotic translation elongation factor 1 subunit alpha 1 (eEF1α1), which was confirmed by microcalorimetry. Only restricted, nondisrupted spermatogenesis in rats was observed after chronic glyphosate treatments (0.7 and 7 mg/L). Cytostatic and antiproliferative effects of glyphosate in GC-1 and SUP-B15 cells were indicated. Meta-analysis of public health data suggested a possible effect of glyphosate use on sperm count. The in silico, in vitro, and in vivo experimental results as well as the metastatistics indicate side effects of chronic glyphosate exposure. Together, these findings indicate that glyphosate delays protein synthesis through an interaction with eEF1α1, thereby suppressing spermatogenesis and cell growth.

Groundwater as a potential cause of Chronic Kidney Disease of unknown etiology (CKDu) in Sri Lanka: a review

The cause of Chronic Kidney Disease of unknown etiology (CKDu) in the rural dry zone of Sri Lanka remains unidentified, despite vast research efforts that brought about an extensive list of potential risk factors. Among these, the long-term exposure to various nephrotoxic elements through drinking groundwater was widely suspected owing to the unique geographical distribution of the disease. This review focuses on such well-known hypotheses suspecting the relations with fluoride, hardness, major ions, heavy metals, metalloids, organic matter, agrochemical residues, pathogens, and bacterial toxins in the groundwaters of the CKDu-endemic region. It was comprehensively discussed why each of these constituents was considered a risk factor of CKDu, how could they possibly trigger the pathogenesis of the disease, what was the evidence that supported or failed each hypothesis, and whether providing safe drinking water had been effective at mitigating the progression of the disease. Although plenty of circumstantial evidence supported an etiology related to groundwater for CKDu, it was impossible to elucidate the cause-effect relationships between drinking impaired groundwater and the occurrence of the disease. Future research should be effectively designed to clarify the role of groundwater in the onset of CKDu by taking into account the gaps in past research.

Epigenetic Changes Associated With Exposure to Glyphosate-Based Herbicides in Mammals

Glyphosate is a phosphonomethyl amino acid derivative present in a number of non-selective and systemic herbicides. During the last years the use of glyphosate-based herbicide (GBH) has been increasing exponentially around the world, including Argentina. This fact added to the detection of glyphosate, and its main metabolite, amino methylphosphonic acid (AMPA), in environmental matrices such as soil, sediments, and food, has generated great concern about its risks for humans, animals, and environment. During the last years, there were controversy and intense debate regarding the toxicological effects of these compounds associated with the endocrine system, cancer, reproduction, and development. The mechanisms of action of GBH and their metabolites are still under investigation, although recent findings have shown that they could comprise epigenetic modifications. These are reversible mechanisms linked to tissue-specific silencing of gene expression, genomic imprinting, and tumor growth. Particularly, glyphosate, GBH, and AMPA have been reported to produce changes in global DNA methylation, methylation of specific genes, histone modification, and differential expression of non-coding RNAs in human cells and rodents. Importantly, the epigenome could be heritable and could lead to disease long after the exposure has ended. This mini-review summarizes the epigenetic changes produced by glyphosate, GBHs, and AMPA in humans and rodents and proposes it as a potential mechanism of action through which these chemical compounds could alter body functions.

A comparative review: Chronic Kidney Disease of unknown etiology (CKDu) research conducted in Latin America versus Asia

INTRODUCTION

The incidence of chronic kidney disease of unknown or uncertain etiology (CKDu) is recognized as a global non-communicable health crisis. The goal of this work is to compare the types of research studies in Latin America and Asia, two regions with increasing CKDu incidence.

METHODS

A comparative literature review was conducted to evaluate the CKDu research design for peer-reviewed articles published from 2015 to 2019. Full texts were reviewed to identify study location, study type, study design, risk factors evaluated, and if applicable, sample type and number.

RESULTS

In Asia and Latin America, 82 and 65 articles were identified in total, respectively, with 55 field studies in Asia versus 34 in Latin America. In Asia, research was focused on drinking water (34), heavy metals (20), and agrochemical product usage (19) as potential risk factors. In Latin America, research focused mostly on heat stress/dehydration (36) and agrochemical product usage (18) as potential CKDu risk factors. Biological samples were collected more frequently than environmental samples, especially in Latin America.

DISCUSSION

Research to pinpoint the risk factors associated with CKDu to date is not standardized and typically limited in geographical scope. The emphasis of CKDu research varies by geographic region, with a greater priority placed on water quality and chemical exposure in Asia, versus dehydration and heat stress in Latin America. Using a harmonized approach to CKDu research would yield improved understanding of the risk factors associated with CKDu and how they compare across affected regions.

Renal tubular injury induced by glyphosate combined with hard water: the role of cytosolic phospholipase A2

Background

The combined effects of glyphosate and hard water on chronic kidney disease of unknown etiology (CDKu) have attracted much interest, but the mechanisms remain unknown. Cytoplasmic phospholipase A₂ (cPLA₂) plays a key role in the acute and chronic inflammatory reactions. This study explored the effect of glyphosate combined with hard water on renal tubules and the possible targets and mechanisms involved.

Methods

In vivo experiments were conducted to investigate the synergistic effects and potential mechanisms of glyphosate and hard water on renal tubular injury in mice.

Results

Administration of glyphosate in mice resulted in elevated levels of β2-microglobulin (β₂-MG), albumin (ALB), and serum creatinine (SCr) compared to control mice. This increase was more pronounce when glyphosate was combined with hard water. In the glyphosate-treated mice, small areas of the kidney revealed fibroblast proliferation and vacuolar degeneration, particularly at the higher dose of 400 mg/kg glyphosate. However, the combination of glyphosate and hard water induced an even greater degree of pathological changes in the kidney. Immunofluorescence and western blot analyses showed that glyphosate and hard water had a coordinated effect on calcium ions (Ca²⁺)-activated phospholipase A₂ and the activation may play a key role in inflammation and renal tubular injury. Exposure to glyphosate alone or glyphosate plus hard water increased the levels of oxidative stress markers and inflammatory biomarkers, namely, thromboxane A₂ (TX-A₂), leukotriene B₄ (LTB₄), prostaglandin E₂ (PGE₂), nitric oxide synthase (NOS), and nitric oxide (NO). Parameters of oxidative stress, including the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were decreased. Further analysis showed that the levels of these biomarkers were significantly different between the mice treated with glyphosate plus hard water and the mice treated with glyphosate alone.

Conclusions

These findings suggested that hard water combined with glyphosate can induce renal tubular injury in mice, and this may involve mitogen-activated protein kinases (MAPK)/cytosolic phospholipase A₂ (cPLA₂)/arachidonic acid (AA) and its downstream factors.

Progression of potential etiologies of the chronic kidney disease of unknown etiology in Sri Lanka

Chronic kidney disease of unknown etiology (CKDu) is a major health issue in agricultural areas in Sri Lanka. Despite many attempts to identifying causative factors of CKDu, the real cause/s remain/s elusive to date. Understanding the progression of potential etiologies may provide valuable insight into this quest. Literature relevant to CKDu addresses several etiologies, including quality of drinking water in the affected areas including hardness, fluoride, ionicity, agrochemical and heavy metal contaminations, consumption of contaminated food, and the genetic makeup of vulnerable populations. Progression of the etiologies revealed persistent interest in heavy metals of multiple origins: waterborne, foodborne, or soilborne. Secondary factors, such as water hardness, fluoride, and ionicity appear to act synergistically, aggravating the role of heavy metals on the onset, and the progression of CKDu. Demographical factors, such as male sex, over 50 years of age, agriculture-related occupation, and the consumption of contaminated water and food are intricately related with the disease progression while other minor risk factors such as smoking, alcohol consumption, etc. exasperate the disease condition. Since, none of these etiologies are examined adequately, conducting laboratory exposure studies under in-vivo and in-vitro settings to understand their role in CKDu is crucial.

Kidney developmental effects of metal-herbicide mixtures: Implications for chronic kidney disease of unknown etiology

Chronic kidney disease of unknown etiology (CKDu) is an emerging global concern affecting several agricultural communities in the Americas and South Asia. Environmental contaminants such as heavy metals (e.g., Cd, As, Pb, and V) and organic pesticides (e.g., glyphosate) in the drinking water have been hypothesized to play a role in childhood onset and progression of this disease. However, a comprehensive analysis of chemical contaminants in the drinking water and effects of these compounds and their mixtures on kidney development and function remains unknown. Here, we conducted targeted and non-targeted chemical analyses of sediment and drinking water in CKDu affected regions in Sri Lanka, one of the most affected countries. Using zebrafish Danio rerio, a toxicology and kidney disease model, we then examined kidney developmental effects of exposure to (i) environmentally derived samples from CKDu endemic and non-endemic regions and (ii) Cd, As, V, Pb, and glyphosate as individual compounds and in mixtures. We found that drinking water is contaminated with various organic chemicals including nephrotoxic compounds as well as heavy metals, but at levels considered safe for drinking. Histological studies and gene expression analyses examining markers of kidney development (pax2a) and kidney injury (kim1) showed novel metal and glyphosate-metal mixture specific effects on kidney development. Mitochondrial dysfunction is directly linked to kidney failure, and examination of mixture specific mitochondrial toxicity showed altered mitochondrial function following treatment with environmental samples from endemic regions. Collectively, we show that metals in drinking water, even at safe levels, can impede kidney development at an early age, potentiating increased susceptibility to other agrochemicals such as glyphosate. Drinking water contaminant effects on mitochondria can further contribute to progression of kidney dysfunction and our mitochondrial assay may help identify regions at risk of CKDu.

Engineered glyphosate oxidase coupled to spore-based chemiluminescence system for glyphosate detection

The extensive and intensive utilization of glyphosate (Glyp) caused public concerns on the potential risk of environment and health resulted from the chemical residues. Therefore, the development of a high-selective, low-cost and easy-operation Glyp detection methods is highly desired. Screening highly selective enzymes by directed evolution is important in practical applications. Herein, a glyphosate oxidase (GlypO) preferring substrate Glyp to produce H2O2 was obtained via directed evolution from glycine oxidase obtained from Bacillus cereus (BceGO). The catalytic efficiency, specificity constant, and affinity enhancement factor of GlypO toward Glyp were increased by 2.85 × 103-fold; 2.25 × 105-fold; and 9.64 × 104-fold, respectively, compared with those of BceGO. The catalytic efficiency toward glycine decreased by 78.60-fold. The spores of Bacillus subtilis (B. subtilis) effectively catalyzed luminol-H2O2 reaction to create excellent chemiluminescence (CL) signal because CotA-laccase exists on their surface. Based on these findings, a new CL biosensor via coupling to biological reaction system was presented for Glyp detection. The CL biosensor exhibited several advantages, such as eco-friendliness, low cost, high selectivity and sensitivity, and good practical application prospects for environmental pollution control.

Determination of Glyphosate in Water from a Rural Locality in México and Its Implications for the Population Based on Water Consumption and Use Habits

Glyphosate is a broad-spectrum herbicide widely used worldwide. Indeed, it is the herbicide most applied to all Mexican crops. Due to the overuse and poor disposal of the waste, this herbicide can reach the aquatic environments such as groundwater and surface water. Thus, there is a clear need to implement monitoring and surveillance programs for evaluating and controlling the exposure to this herbicide in rural populations. The goal of this study was to quantify the presence of glyphosate in different water bodies (groundwater, surface and drinking water) as well as to identify the uses and managements of water resources by rural communities to evaluate the potential human exposure to glyphosate in the Tenampulco region of the Mexican state of Puebla. Measurements were performed by a rapid and cost-effective ELISA-based method in groundwater and surface water from various sampling sites of the Tenampulco region. Glyphosate was detected in all groundwater samples to be below the maximum limit for glyphosate in water in Mexico. Nevertheless, these results indicate an exposure of glyphosate in these agricultural communities and the need to establish a monitoring program.

Concentration Distribution and Analysis of Urinary Glyphosate and Its Metabolites in Occupationally Exposed Workers in Eastern China

Background: There are few published studies concerning occupational exposure to glyphosate (GLY), and these are limited to spraying, horticulture and other agricultural aspects. Therefore, the concentration of glyphosate and its metabolite aminomethylphosphonic acid (AMPA), in the urine of workers exposed to glyphosate during glyphosate production was determined, and the relationship between internal (urinary glyphosate and AMPA concentration) and external exposure dose (time weighted average (TWA) value of glyphosate in the air of workplace) was analyzed. Methods: To avoid the influence of preparations, we selected people who were only involved in GLY production (without exposure to its preparations) as our research subjects. We collected 134 urine samples of workers exposed to GLY (prototype, not preparation). The urinary concentrations of GLY and AMPA (internal exposure dose) were detected by gas chromatography-mass spectrometry. The subjects' exposure to the amount of GLY in the air (external dose) was determined using ion chromatography. Conventional statistical methods, including quartiles, t-tests and regression analysis, were applied for data processing. Results: An on-site investigation revealed that the workers involved in centrifugation, crystallization, drying, and packaging and feeding were exposed to GLY. The TWA value of GLY in the workshop air was <0.02 mg/m3-34.58 mg/m3. The detection rates of GLY and AMPA in the urine samples were 86.6% and 81.3%, respectively. The concentration of urinary GLY was <0.020-17.202 mg/L (median, 0.292 mg/L). The urinary AMPA concentration was <0.010 mg/L-2.730 mg/L (median, 0.068 mg/L). The geometric means were 0.262 mg/L and 0.072 mg/L for GLY and AMPA, respectively. There was a correlation between the urinary concentration of GLY and AMPA and the TWA value of exposed workers (correlation coefficient [r] = 0.914 and 0.683, respectively; p < 0.01). Furthermore, there was a correlation between the urinary concentration of GLY and AMPA in the exposure group (r = 0.736, p < 0.01). Conclusions: The urinary concentration of GLY and AMPA of workers was correlated with the TWA value of workers' exposure, which could reflect the actual exposure of the workers.

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.

Simultaneous and direct determination of glyphosate and AMPA in water samples from the hydroponic cultivation of eucalyptus seedlings using HPLC-ICP-MS/MS

Glyphosate is the main herbicide currently used in the world due to wide applicability and efficiency in controlling weeds in many crops. However, its overuse may lead to undesirable impacts on the environment and to human health in the long run. This present study aimed to optimize and validate solid phase extraction (SPE) using an anionic resin for the simultaneous and direct determination of glyphosate and aminomethylphosphonic acid (AMPA) in water samples using high-performance liquid chromatography combined with inductively coupled plasma with triple quadrupole mass spectrometer (HPLC-ICP-MS/MS). The results showed that recovery percentage and relative standard deviation were 103.9 ± 7.9 and 99.40 ± 9.9% for glyphosate and AMPA, respectively. The validation certified that the method was precise, accurate, linear, and selective, with a limit of quantification of 1.09 and 0.29 μg L-1 for glyphosate and AMPA, respectively. The optimized methodology reached the concentration factor of 250 times and was successfully applied to analyze water samples from hydroponic cultivation of the eucalyptus seedlings. The results showed that the exudation process occurs at glyphosate doses starting from 2 L ha-1.

Glyphosate exposures and kidney injury biomarkers in infants and young children

The goal of this study was to assess biomarkers of exposure to glyphosate and assess potential associations with renal function in children. Glyphosate is used ubiquitously in agriculture worldwide. While previous studies have indicated that glyphosate may have nephrotoxic effects, few have examined potential effects on kidney function in children. We leveraged three cohorts across different phases of child development and measured urinary levels of glyphosate. We evaluated associations of glyphosate with three biomarkers of kidney injury: albuminuria (ACR), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury marker 1 (KIM-1). Multivariable regression analyses examined associations of glyphosate with kidney injury biomarkers controlling for covariates. We identified glyphosate in 11.1% of the total participants. The herbicide was detected more frequently in the neonate population (30%). Multivariable regression models failed to identify significant associations of log-transformed glyphosate with any of the kidney injury biomarkers, controlling for covariates age, sex, and maternal education. While we confirm detectability of glyphosate in children's urine at various ages and stages of life, there is no evidence in this study for renal injury in children exposed to low levels of glyphosate. Further studies of larger sample size are indicated to better understand putative deleterious effects of the herbicide after different levels of exposure.

Prevalence of chronic kidney disease in Sri Lanka: A profile of affected districts reliant on groundwater

This analysis provides new estimates of chronic kidney disease (CKD) prevalence - including CKD of unknown etiology (CKDu) - across ten districts most affected by CKD in Sri Lanka, including an examination of rural households' historical reliance on groundwater consumption. A carefully designed household survey provides information on whether these households self-reported having a member in the decade prior to 2018, who had been clinically diagnosed with CKD. Households were classified according to whether or not they had used groundwater (from household wells, agro-wells or springs) as their primary source for drinking or cooking for at least five years between 1999 and 2018. More than 98% of households reported having consumed groundwater as their primary source of drinking or cooking water for at least five of those years and >15% of households reported having at least one CKD-affected member in the ten-year period up to 2018, but these numbers varied across and within districts. The reported characteristics of symptomatic individuals reveal that the incidence of CKD was significantly higher among females (62%) than males (38%). In addition to CKD, about 63% of symptomatic individuals had hypertension and about one-third of them also had diabetes. About 33% of the symptomatic individuals had neither diabetes nor hypertension, where this group most closely fits commonly used definitions of CKDu. With a survey response of over 8000 households comprising as many as 30,000 individuals, these data illustrate the scale of CKD in the most-affected districts of Sri Lanka on an aggregate basis as well as revealing differences across districts and at the sub-district level.

Chronic kidney disease of unknown aetiology in Sri Lanka and the exposure to environmental chemicals: a review of literature

Chronic kidney disease of unknown aetiology (CKDu) has emerged as a serious health issue in Sri Lanka. The disease has been recorded in the North Central Province of the country. While studies have elicited many hypotheses concerning the pathogenicity of CKDu, none adequately explains the cause of CKDu and the measures needed to minimise its occurrence. Nephrotoxic heavy metal (oid)s such as cadmium, arsenic, lead, and chromium are present in biological samples of people from endemic areas. This review appraises evidence on the effects of long-term exposure to low concentration of nephrotoxic heavy metals, which could be the principal cause of CKDu. Although a considerable variation exists in metal concentrations in patients' blood and urine, higher levels of heavy metals were consistently observed in affected areas. This review finds that the populations in the endemic areas are exposed to heavy metal (oid)s at low concentrations, which are considered as safe levels; nevertheless, it influences the incidence of CKDu. Recent global studies on chronic kidney disease (CKD) revealed a low concentration of heavy metals in diseased patients. Research findings indicated that CKDu patients in Sri Lanka demonstrated similar blood levels of Cd, Pb, and higher concentrations of Cr than that have been reported globally. Further studies on the influence of combinations of nephrotoxic heavy metals at low concentrations on reduced glomerular filtration rate and other renal biomarkers could explain CKDu pathogenicity.

Environmental exposures in young adults with declining kidney function in a population at risk of Mesoamerican nephropathy

OBJECTIVES

There is an epidemic of Mesoamerican nephropathy (MeN) in Central America, where sugarcane production is prominent. Numerous causes are proposed, but to date limited evidence supports any one hypothesis. A nested case-control study using biosamples from a rural, community-based follow-up study of 350 young adults from Northwest Nicaragua at risk of MeN was conducted with the aim of characterising the associations between urinary concentrations of metals, pesticides and mycotoxins from samples collected in the first 6 months and decline in kidney function over 2 years.

METHODS

Urine samples collected at baseline (pre-sugarcane harvest) and the first 6 month follow-up (post-sugarcane harvest) visit were tested. Twelve metals and metalloids (aluminium, total arsenic, cadmium, chromium, cobalt, copper, lead, manganese, mercury, selenium, silicon and strontium) were analysed by inductively coupled plasma-mass spectrometry. Twelve pesticides or their metabolites (2,4-dichlorophenoxyacetic acid, 3-phenoxybenzoic acid, 4-fluoro-3-phenoxybenzoic acid, chloro-3,3,3-trifluoro-1-propen-1-yl-2,2-dimethylcyclopropanecarboxylic acid, cis/trans 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, ethylenethiourea, glyphosate, 4-chloro-2-methylphenoxy acetic acid, 3-hydroxy-pyrimetanil, 5-hydroxytiabendazole, hydroxy-tebuconazole and 3,5,6-trichloro-2-pyridinol) and two mycotoxins (ochratoxin A (OTA) and citrinin (CIT)) were analysed by liquid chromatography coupled-mass spectrometry. Differences in the creatinine-corrected urinary concentrations of the measured exposures between outcome groups (participants with stable vs declining kidney function) were examined.

RESULTS

Elevated levels of aluminium and total arsenic as well as metabolites of several pesticides were detected across the population. No differences were identified between the declining and stable groups in the levels of metals or pesticides tested. OTA and CIT were below the limit of detection.

CONCLUSIONS

The tested metals, metalloids, pesticides and mycotoxins were not associated with loss of kidney function in participants at-risk of MeN.

Influence of electrolyte composition and pH on glyphosate sorption by cow-dung amended soil

This study investigated the pH-dependent relationship between glyphosate and soils before (NS) and after amendment with cow-dung, CD (SACD). Sorption isotherms were generated using batch equilibration techniques from CaCl2, KCl, CaSO4 and Ca(H2PO4)2 background electrolytes. Linear partition coefficients decreased with increase in pH in the order: CaCl2>KCl > CaSO4>Ca(H2PO4)2, which reflect both the effect of the inorganic anion in terms of competition and the cation in terms of bridging interactions. However, soil amendment with CD minimized the inhibitory effect of pH increase on glyphosate sorption. Variations in glyphosate sorption from CaCl2 and Ca(H2PO4)2 were attributed to fraction of hydrophilic contribution while variations in sorption from CaCl2 and KCl were attributed to Ca-bridging and ranged from 22 to 70% across the two soils. Estimated hydrophobic partitioning ( K OC pH ) systematically decreased with increasing soil solution pH from 36 to 3% and 5 to <1% in NS and SACD, respectively. Greater sorption in NS over SACD was partly attributed to higher phosphate level in SACD which is preferentially sorbed over glyphosate. This study noted CD application as soil amendment for agriculture could impede glyphosate sorption and facilitate its off-site leaching and contamination of surface and groundwater.

Acute exposure to chlorpyrifos and glyphosate induces changes in hemolymph biochemical parameters in the crayfish, Astacus leptodactylus (Eschscholtz, 1823)

Acute and subacute toxicity tests for chlorpyrifos and glyphosate were performed on the crayfish, Astacus leptodactylus. The crayfish were divided into a control group and four experimental groups with exposure from 50.18 to 301.11 μg L-1 of chlorpyrifos for 96 h under semi-static test conditions. In the same experiment, the crayfish were exposed to different concentrations of glyphosate (from 0.0, 8.14 to 13.05 mg L-1) for 96 h. Mortality was recorded, and the median lethal concentrations (LC50) were calculated using probit analysis. The 96 h LC50 values of chlorpyrifos and glyphosate to A. leptodactylus were 49.55 ± 4.66 μg L-1 and 7.83 ± 0.50 mg L-1, respectively. The results showed that chlorpyrifos was a few hundred times more toxic than glyphosate for the crayfish. Then, the crayfish were exposed to different subacute concentrations of chlorpyrifos (12.5 and 25 μg L-1) and glyphosate (2 mg L-1 and 4 mg L-1) for seven days, and their toxicity was evaluated through several hemolymph biochemical parameters. Chlorpyrifos and glyphosate exposure caused a significant (P < 0.01) increase in the activity of lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT). The results showed a significant (P < 0.01) decrease in acetylcholinesterase (AChE), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and phenoloxidase (PO) activities in the hemolymph of the crayfish exposed to chlorpyrifos and glyphosate. The total protein and cholesterol levels showed a significant decrease (P < 0.01) in the hemolymph of the crayfish after seven days of exposure to chlorpyrifos and glyphosate. There was a significant increase in triglycerides and glucose levels in treated crayfish. These results show that chlorpyrifos is highly toxic, while glyphosate is moderately toxic to A. leptodactylus. According to the results, subacute concentrations of chlorpyrifos and glyphosate could lead to a collapse of cellular homeostasis and changes in the hemolymph biochemical parameters in the crayfish. Physiological changes caused by exposure to chlorpyrifos and glyphosate in A. leptodactylus may have direct effects on the survival of these organisms.

Glyphosate's Synergistic Toxicity in Combination with Other Factors as a Cause of Chronic Kidney Disease of Unknown Origin

Chronic kidney disease of unknown etiology (CKDu) is a global epidemic. Sri Lanka has experienced a doubling of the disease every 4 or 5 years since it was first identified in the North Central province in the mid-1990s. The disease primarily affects people in agricultural regions who are missing the commonly known risk factors for CKD. Sri Lanka is not alone: health workers have reported prevalence of CKDu in Mexico, Nicaragua, El Salvador, and the state of Andhra Pradesh in India. A global search for the cause of CKDu has not identified a single factor, but rather many factors that may contribute to the etiology of the disease. Some of these factors include heat stroke leading to dehydration, toxic metals such as cadmium and arsenic, fluoride, low selenium, toxigenic cyanobacteria, nutritionally deficient diet and mycotoxins from mold exposure. Furthermore, exposure to agrichemicals, particularly glyphosate and paraquat, are likely compounding factors, and may be the primary factors. Here, we argue that glyphosate in particular is working synergistically with most of the other factors to increase toxic effects. We propose, further, that glyphosate causes insidious harm through its action as an amino acid analogue of glycine, and that this interferes with natural protective mechanisms against other exposures. Glyphosate's synergistic health effects in combination with exposure to other pollutants, in particular paraquat, and physical labor in the ubiquitous high temperatures of lowland tropical regions, could result in renal damage consistent with CKDu in Sri Lanka.