Roundup Research Articles

Effects of glyphosate-based herbicide on gut microbes and hepatopancreatic metabolism in Pomacea canaliculata

Roundup®, a prominent glyphosate-based herbicide (GBH), holds a significant position in the global market. However, studies of its effects on aquatic invertebrates, including molluscs are limited. Pomacea canaliculata, a large freshwater snail naturally thrives in agricultural environments where GBH is extensively employed. Our investigation involved assessing the impact of two concentrations of GBH (at concentrations of 19.98 mg/L and 59.94 mg/L, corresponding to 6 mg/L and 18 mg/L glyphosate) during a 96 h exposure experiment on the intestinal bacterial composition and metabolites of P. canaliculata. Analysis of the 16 S rRNA gene demonstrated a notable reduction in the alpha diversity of intestinal bacteria due to GBH exposure. Higher GBH concentration caused a significant shift in the relative abundance of dominant bacteria, such as Bacteroides and Paludibacter. We employed widely-targeted metabolomics analysis to analyze alterations in the hepatopancreatic metabolic profile as a consequence of GBH exposure. The shifts in metabolites primarily affected lipid, amino acid, and glucose metabolism, resulting in compromised immune and adaptive capacities in P. canaliculata. These results suggested that exposure to varying GBH concentrations perpetuates adverse effects on intestinal and hepatopancreatic health of P. canaliculata. This study provides an understanding of the negative effects of GBH on P. canaliculata and may sheds light on its potential implications for other molluscs.

Aged polyethylene microplastics and glyphosate-based herbicide co-exposure toxicity in Pacific white shrimp (Litopenaeus vannamei)

Microplastics and glyphosate-based herbicides (GBHs) unavoidably contaminate aquatic environments, yet their combined effect on aquatic organisms has been scarcely investigated. We present a short-term study on individual and combined effects of aged polyethylene (PE) microplastics and GBH exposures at environmentally relevant concentrations on oxidative damage, antioxidant responses, immune parameters, and hepatopancreas histology in shrimp (Litopenaeus vannamei). In addition, acetylcholinesterase (AChE) was evaluated as a biomarker of GBH exposure. After 96 hours of exposure, individual PE microplastic exposure slightly influenced oxidative status, immune parameters, and histology. Decreases in AChE concentration and alterations in oxidative status, immunity, and cell population in hepatopancreas were observed in single GBH-exposed shrimp. The combinations of aged PE microplastics and GBH induced some changes that differed from individual GBH exposures. For instance, some alterations implied that the presence of aged PE microplastics may alter GBH toxicity to L. vannamei (AChE concentration and some expressions of immune-related genes). In conclusion, our results suggest that single exposure of aged PE microplastics at environmental concentration may slightly affect the health of L. vannamei and that aged PE microplastics are likely to modify the toxicity of other co-exposed chemicals.

Glyphosate and its formulated product Roundup Transorb R® affect locomotor activity and reproductive and developmental parameters in Jenynsia lineata fish: An intergenerational study

Glyphosate is the most widely utilized herbicide worldwide due to its effectiveness in controlling agricultural weeds. However, its persistence in aquatic ecosystems has raised concerns about the well-being of non-target organisms such as fish. This study aimed to evaluate the effects of chronic exposure (21 days) to glyphosate or its formulated product Roundup Transorb R®, at an environmentally relevant concentration permitted by regulations in certain countries (65 μg/L of glyphosate), on the locomotor activity and reproductive success of the fish Jenynsia lineata, as well as on the morphology/development and locomotor activity of its offspring, as intergenerational effects. Neither the pure nor formulated herbicide altered the distance traveled and velocity of adult fish exposed to the herbicide (F0), but they negatively affected reproductive success, decreasing the percentage of positive response to the presence of the female, reducing the number of gravid females, causing abortions, and lowering offspring survival (F1). In the F1 generation, a decrease in weight and length was noted along with developmental abnormalities in both treatment groups (pure or formulated glyphosate), with the formulation causing more harm. Observed developmental abnormalities included muscle atrophy, ascites, pigmentary disorders, vertebral agenesis, spinal deviation, and exophthalmia. Furthermore, parental exposure to pure glyphosate led to an increase in the distance traveled and velocity of F1 (hyperlocomotion), whereas exposure to the formulated product resulted in a decrease in these behaviors (hypolocomotion) of F1. These findings highlight the toxic effects of glyphosate at very low concentrations, although varying between pure and formulated, and demonstrate the intergenerational consequences of herbicide exposure, underscoring the risk to the survival of fish offspring in glyphosate-contaminated environments.

Effects of the glyphosate-based herbicide roundup on C. elegans and S. cerevisiae mortality, reproduction, and transcription fidelity

Glyphosate-based weed killers such as Roundup have been implicated in detrimental effects on single- and multicellular eukaryotic model organism health and longevity. However, the mode(s) of action for these effects are currently unknown. In this study, we investigate the impact of exposure to Roundup on two model organisms: Saccharomyces cerevisiae and Caenorhabditis elegans and test the hypothesis that exposure to Roundup decreases transcription fidelity. Population growth assays and motility assays were performed in order to determine the phenotypic effects of Roundup exposure. We also used Rolling-Circle Amplification RNA sequencing to quantify the impact of exposure to Roundup on transcription fidelity in these two model organisms. Our results show that exposure to the glyphosate-based herbicide Roundup increases mortality, reduces reproduction, and increases transcription error rates in C. elegans and S. cerevisiae. We suggest that these effects may be due in part to the involvement of inflammation and oxidative stress, conditions which may also contribute to increases in transcription error rates.

Multigenerational effects of glyphosate-based herbicide and emamectin benzoate insecticide on the reproduction and gene expression of the copepod Pseudodiaptomus annandalei (Sewell, 1919)

This study investigates the effects of glyphosate-based herbicide (GLY) and pure emamectin benzoate (EB) insecticide on the brackish copepod Pseudodiaptomus annandalei. The 96h median lethal concentration (96 h LC50) was higher in the GLY exposure (male: 3420.96 ± 394.67 μg/L; female: 3093.46 ± 240.67 μg/L) than in the EB (male: 79.10 ± 7.30 μg/L; female: 6.38 ± 0.72 μg/L). Based on the result of 96h LC50, we further examined the effects of GLY and EB exposures at sub-lethal concentrations on the naupliar production of P. annandalei. Subsequently, a multigenerational experiment was conducted to assess the long-term impact of GLY and EB at concentrations 375 μg/L, and 0.025 μg/L respectively determined by sub-lethal exposure testing. During four consecutive generations, population growth, clutch size, prosome length and width, and sex ratio were measured. The copepods exposed to GLY and EB showed lower population growth but higher clutch size than the control group in most generations. Gene expression analysis indicated that GLY and EB exposures resulted in the downregulation of reproduction-related (vitellogenin) and growth-related (myosin heavy chain) genes, whereas a stress-related gene (heat shock protein 70) was upregulated after multigenerational exposure. The results of the toxicity test after post-multigenerational exposure indicated that the long-term GLY-exposed P. annandalei displayed greater vulnerability towards GLY toxicity compared to newly-exposed individuals. Whereas, the tolerance of EB was significantly higher in the long-term exposed copepod than in newly-exposed individuals. This suggests that P. annandalei might have greater adaptability towards EB toxicity than towards GLY toxicity. This study reports for the first time the impacts of common pesticides on the copepod P. annandalei, which have implications for environmental risk assessment and contributes to a better understanding of copepod physiological responses towards pesticide contaminations.

Effects of glyphosate herbicide ingestion on kidney function in rats on a balanced diet.

Glyphosate is the most widely used herbicide worldwide and in Brazil. There is currently increasing concern about the effects of glyphosate on human health. The Brazilian Institute for Consumer Protection showed data on the presence of glyphosate in some of Brazil's most consumed ultra-processed products. Currently, regulations on the upper limit for these residues in ultra-processed foods have yet to be established by the National Health Surveillance, and ultra-processed food consumption is independently associated with an increased risk of incident chronic kidney disease. Since an unbalanced diet can interfere with kidney function, this study aims to investigate the effect of daily intake of 5 mg/kg bw glyphosate in conjunction with a balanced diet and the possible impact on renal function in rats. Kidney function, kidney weight, markers of renal injury, and oxidative stress were evaluated. There was a decrease in kidney weight. The main histopathological alterations in renal tissues were vacuolation in the initial stage and upregulation of the kidney injury marker KIM-1. Renal injury is associated with increased production of reactive oxygen species in mitochondria. This study showed changes in the kidney of rats exposed to a balanced diet with glyphosate, suggesting a potential risk to human kidney. Presumably, ultra-processed food that contain glyphosate can potentiate this risk. The relevance of these results lies in drawing attention to the need to regulate glyphosate concentration in ultra-processed foods in the future.

Effectiveness of integrating mowing and systemic herbicides applied with a weed wiper for Sporobolus indicus var. pyramidalis management in Florida

Abstract Giant smutgrass [Sporobolus indicus (L.) R. Br. var. pyramidalis (P. Beauv.) Veldkamp] is an invasive species in grasslands, and herbicide application has been the most efficient management method to suppress this weed. Experiments were conducted in 2017 and 2018 to determine the effects of wiping glyphosate and hexazinone on S. indicus var. pyramidalis. A dose–response experiment using a handheld weed wiper was established with 20 treatments comprising two herbicides (glyphosate and hexazinone), uni- and bidirectional wiping methods, and 5 herbicide concentrations (6.25% v/v, 12.5% v/v, 25.0% v/v, 50.0% v/v, and 100% v/v basis). Data were collected 30 and 60 d after treatment (DAT). An ATV-mounted roto-type weed-wiper experiment was established in a strip-plot arrangement, with mowing as the horizontal strip, the wiping method (unidirectional vs. bidirectional) randomized as the vertical strip with three dosages of each herbicide for a total of 12 wiping treatments. Data were collected at 35 and 90 DAT. The percent plant mortality was calculated using differences in pre- and posttreatment plant counts. ANOVA and log-logistic linear regression were used to analyze the data. The dose–response experiment showed that S. indicus var. pyramidalis mortality increased with herbicide concentration, and mortality was greater with the bidirectional wiping method compared with the unidirectional method. Treatments wiped bidirectionally with glyphosate at 70% v/v, hexazinone at 30% v/v, and hexazinone at 60% v/v resulted in S. indicus var. pyramidalis mortality ranging from 75% to 98% by 90 DAT across all locations. The ATV-mounted weed-wiper experiment showed that mowing before herbicide application with weed wipers decreased the efficacy of both herbicides. Overall, both experiments indicate that S. indicus var. pyramidalis should be wiped bidirectionally using either glyphosate (70% v/v) or hexazinone (at least 30% v/v) to obtain satisfactory control. Further work should be conducted to determine whether seasonality impacts the response of S. indicus var. pyramidalis to mowing and the application of these herbicides.

Does roundup® affect worker bees (Apis mellifera) that inhabit areas of high agrochemical pressure?

Glyphosate-based herbicides (GBHs) find wide application in conventional agroecosystems due to their effective mode of action. The impact of herbicides on bees may be underestimated due to the scarcity of studies assessing various exposure routes to GBHs, including contact and ingestion of contaminated food. This study evaluated the survival, food consumption, and body weight of honey bee populations in three different locations, characterized by different degrees of exposure to GBHs. In bioassays, honey bees were exposed to diets containing sucrose solutions infused with glyphosate, with dosages ranging from 0 to 14 mg (a.i./bee). During the experiment, the honey bee population had a period of exposure (6 h) to the syrup infused with glyphosate. Mortality counts and feeder weight measurements were performed to assess the effects. A significant reduction in syrup intake was observed in all three bee populations during the Roundup® exposure phase, leading to a decrease in GBH intake. Notably, the decrease in syrup consumption emerged as the main factor contributing to the lower body weight observed among honey bees from low- and high-impact locations, persisting into the post-exposure period. Overall, the results demonstrate that honey bees in the high-impact region are more sensitive to Roundup®. However, studies using biochemical biomarkers are still necessary to unravel how glyphosate interferes with the acquisition and expenditure of energy during periods of exposure of honey bees and which physiological changes allow them to adapt to inhabited places with high agricultural pressure.

Injection-based approaches for controlling Douglas-fir (Pseudotsuga menziesii) invasion in conservation efforts of the Patagonian forest

Abstract Invasion by nonnative woody species poses a major threat to the environment, biodiversity, and economies worldwide. Nahuel Huapi National Park in Argentina is a protected area for habitat conservation that harbors several invasive Pinaceae species, where Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] is one of the most aggressive and abundant conifer tree invaders. Management of invasions in protected areas must include efficient, easy to deploy, and cost-effective techniques, while reducing the impact on native ecosystems. Because the region has no control measures applied other than conventional felling, we analyzed the effectiveness of two systemic herbicides (glyphosate and aminopyralid + triclopyr) at two different concentrations, applied with the drill and fill method. We then quantified defoliation of P. menziesii trees 6, 12, and 24 mo after application and performed an economic cost analysis to determine profitability. For the application, the trees were grouped into diameter at breast height classes and randomly assigned to one of the four treatments. Herbicide doses were adjusted according to tree size. We found that glyphosate at high concentrations completely defoliated 33% of the trees after 6 mo and 87% after 12 and 24 mo. Glyphosate at low concentrations defoliated almost 30% of the trees after 24 mo, most of which were smaller trees. The aminopyralid + triclopyr treatment did not produce significant defoliation at any of the tested concentrations. When compared with conventional felling, the drill and fill method was found to reduce removal costs by 98%. We observe that differences in costs are mainly due to dead trees that remain standing, decompose slowly, and do not generate costs associated with their removal and debris management. Drill and fill is a suitable method for treating scattered trees in a native forest community, with reduced environmental consequences compared with other removal techniques currently applied within conservation areas of the Patagonian forest.

Chemical desiccation of potato haulms to increase skin hardness and potato yield

Desiccation of potato crops using herbicides is one of the methods widely used by farmers. Desiccation affects several key aspects such as tuber yield and potato skin hardness. This study aimed to investigate the effects of desiccation on potato (Solanum tuberosum L.) on skin hardness and yield. Experimental methods were used by varying the level of desiccation on different herbicide groups. Ammonium glufosinate, glyphosate, paraquat and saflufenacil herbicides were used in this study which were then compared with manual trimming and no desiccation treatment. The results showed that all herbicides reached a percentage of desiccation above 95% on the 15 days after application. All herbicide treatments other than glyphosate showed the same potato skin hardness as the manual trimming treatment and were harder than potato tubers without desiccation treatment. Desiccation using ammonium glufosinate herbicide at 375 g a.i./ha had the highest potato tuber yield compared to other herbicide applications.

Glyphosate resistance and biodegradation by Burkholderia cenocepacia CEIB S5-2.

Glyphosate is a broad spectrum and non-selective herbicide employed to control different weeds in agricultural and urban zones and to facilitate the harvest of various crops. Currently, glyphosate-based formulations are the most employed herbicides in agriculture worldwide. Extensive use of glyphosate has been related to environmental pollution events and adverse effects on non-target organisms, including humans. Reducing the presence of glyphosate in the environment and its potential adverse effects requires the development of remediation and treatment alternatives. Bioremediation with microorganisms has been proposed as a feasible alternative for treating glyphosate pollution. The present study reports the glyphosate resistance profile and degradation capacity of the bacterial strain Burkholderia cenocepacia CEIB S5-2, isolated from an agricultural field in Morelos-México. According to the agar plates and the liquid media inhibition assays, the bacterial strain can resist glyphosate exposure at high concentrations, 2000mg·L-1. In the degradation assays, the bacterial strain was capable of fast degrading glyphosate (50mg·L-1) and the primary degradation metabolite aminomethylphosphonic acid (AMPA) in just eight hours. The analysis of the genomic data of B. cenocepacia CEIB S5-2 revealed the presence of genes that encode enzymes implicated in glyphosate biodegradation through the two metabolic pathways reported, sarcosine and AMPA. This investigation provides novel information about the potential of species of the genus Burkholderia in the degradation of the herbicide glyphosate and its main degradation metabolite (AMPA). Furthermore, the analysis of genomic information allowed us to propose for the first time a metabolic route related to the degradation of glyphosate in this bacterial group. According to the findings of this study, B. cenocepacia CEIB S5-2 displays a great glyphosate biodegradation capability and has the potential to be implemented in glyphosate bioremediation approaches.

Microplastics mitigate the effects of glyphosate on the shikimic acid pathway enzymes in cyanobacteria

Microplastics, an environmental contaminant, can directly harm aquatic organisms and alter the toxicity and availability of other pollutants. The herbicide glyphosate (N-(phosphonomethyl) glycine) exerts its toxicity by inhibiting 5-enol-pyruvyl-shikimate-3-phosphate synthase (EPSPS), a key enzyme belonging to shikimic acid pathway that leads to the biosynthesis of aromatic amino acids; tolerance, instead, is dependent on a glyphosate -resistant EPSPS. We tested the effects of 0,2mM glyphosate alone and in combination with 170 mg/mL polyethylene microplastics (MPs) on the expression of EPSPS and chorismate synthase (ChS) on a culture of the cyanobacterium Limnospira maxima. Glyphosate caused the highest mortality after one week, with the resistant population surviving thereafter.However, when the culture was exposed to the combined treatment the mortality decreased. Proteomic profiles of treated cultures demonstrated that both enzymes were accumulated during the 21 days glyphosate treatment, suggesting that the surviving population of L. maxima might express glyphosate-resistant target enzymes. Treatment with combined solution caused a decrease of EPSPS and ChS levels compared to those of glyphosate alone. Our results strongly suggest that microplastics mitigate the toxicity of glyphosate towards target enzymes of the shikimic acid pathway, thereby increasing the resistance capacity of the L. maxima strain.

Assessing testicular morphofunctionality under Roundup WG® herbicide exposure in zebrafish.

Glyphosate-based herbicides, like Roundup WG® (RWG) used for a range of crops, such as corn, soybean, coffee, sugarcane, rice, apple, and citrus, can reach aquatic ecosystems and impact non-target organisms like fish. Thus, the fish were exposed to three RWG concentrations plus one negative control, which represents the concentration allowed for inland Brazilian waters and concentrations found in surface water worldwide (0.0, 0.065, 0.65, and 6.5mg a.i./L) for 7 and 15days. Morphological analysis revealed significant alterations in the testicular structure, particularly in Sertoli cell extensions and cytoplasmic bridges between germ cells. Subcellular compartments also displayed alterations, including dilated mitochondria and the loss of electron density and autophagic vesicles. Gene transcript levels related to autophagy and steroidogenic regulation were upregulated in exposed fish. Germ cell quality was also affected, increasing ROS (reactive oxygen species) production and DNA fragmentation. The study highlighted the RWG reproductive toxicity, providing valuable insights into understanding the morphofunctional alterations in somatic and germ cells of Danio rerio. In conclusion, the environmental relevant concentrations used in this study were toxic to male somatic and germ cells, which raises a concern about the concentrations considered safe for human and animal use.

Combined effect of light and glyphosate herbicide on growth rate of marine diatom algae.

The effect of glyphosate herbicide at concentrations of 25, 100, 150 and 200 μg.L-1 on growth characteristics of diatoms C. caspia and T. weissflogii under accumulative growth conditions was investigated. Increasing herbicide concentration in the medium resulted in growth suppression of both species and decreased the final abundance of the cultures in the stationary growth phase. The calculated concentrations of herbicide EC10 and EC50 (10 and 90 μg.L-1 for C. caspia and 7 and 25 μg·L-1 for T. weissflogii, respectively) led to a 10 and 50% reduction in the abundance of the studied cultures relative to the control, are ecologically significant and correspond to the values recorded in aquatic areas. The combined effect of light (in the range of 20-250 µE.m-2.s-1) and glyphosate (calculated concentrations of EC10 and EC50) on the growth characteristics of microalgae was evaluated. An increase in algal sensitivity to light was observed with glyphosate exposure. In both species, the increase in the concentration of glyphosate in the medium led to a decrease in the initial angle of slope of the light curve of growth under conditions of light limitation, a reduction in the value of light saturation of growth, narrowing of the boundaries of the light optimum and an increase in the degree of light inhibition. It is shown that the effect of the combined action of light and glyphosate exceeds the sum of the effects of each factor. This fact should be taken into account in ecotoxicological monitoring when assessing the risks of glyphosate ingress into aquatic ecosystems. An increase in glyphosate concentration in water during periods with high values of solar insolation is potentially dangerous due to a decrease in the photosynthetic activity of algae and a reduction in diatom algae abundance.

Sensitivity of Daphnia spinulata Birabén, 1917 to glyphosate at different salinity levels.

Daphnia spinulata Birabén, 1917 is an endemic cladoceran species, frequent in the zooplankton communities of the shallow lakes of the Pampean region of Argentina. These lakes have varying salinity levels and, being located in agricultural areas, are frequently subject to pesticide pollution. This study aimed to determine the effects of the herbicide glyphosate (Panzer Gold®) in combination with different salinity levels on the biological parameters of D. spinulata and its recovery ability after a short exposure. Three types of assays were performed: an acute toxicity test, a chronic assessment to determine survival, growth and reproduction, and recovery assays under optimal salinity conditions (1g L-1). The LC50-48h of glyphosate was 7.5mg L-1 (CL 3.15 to 11.72). Longevity and the number of offspring and clutches were significantly reduced due to the combined exposure of glyphosate and increased salinity. The timing of the first offspring did not recover after glyphosate exposure. Our results reveal that D. spinulata is sensitive to the herbicide Panzer Gold® at concentrations well below those indicated in the safety data sheet of this commercial formulation, which causes stronger negative effects in conditions of higher salinity. Further research is needed to shed light on the sensitivity of this cladoceran to glyphosate and its variability under other interactive stress factors.

The antioxidant and neuroprotective effects of melatonin on glyphosate-based herbicide-induced affective and cognitive impairments in rats

ABSTRACT Several studies have found that exposure to glyphosate-based herbicides (GBH) can lead to memory impairment and affective disorders. Oxidative stress (OS) is one of the mechanisms that can explain the neurotoxicity of GBH. Consequently, molecules with an antioxidant effect may have neuroprotective potential against GBH-related brain damage. In this work, we aim to evaluate the neuroprotective effect of melatonin (MEL) against affective and cognitive disorders caused by GBH. For this experiment, male Wistar rats received, during the peripubertal period, a daily administration of GBH (75 mg/kg) or GBH + MEL (4 mg/kg). At the end of the treatment, the open field, elevated plus maze, and forced swimming tests were used to explore anxiety levels and depression-like symptoms. While the Y-Maze and Morris Water Maze have been used to detect cognitive deficits, we also measured markers of OS, specifically catalase, nitric oxide, and lipid peroxidation, in the hippocampus and prefrontal cortex. Our results revealed that MEL reduces anxiety and depressive behavior, as well as the cognitive deficits caused by GBH. In addition, co-administration of MEL and GBH induced an improvement in the various markers of OS. The positive action of MEL against OS is therefore one of the mechanisms explaining its neuroprotective power against GBH.

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

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

Determination of glyphosate, glufosinate, and metabolites in honey based on different detection approaches supporting food safety and official controls

Honey, a component of the European diet, faces contamination challenges that impact both consumer and bee health. Glyphosate and glufosinate-based herbicides are widely used in both agriculture and domestic settings, posing potential threats to humans and bees. This study addresses the need for robust analytical methods to detect glyphosate, glufosinate, and their metabolites in honey, considering the complexities of the matrices. Advanced techniques, such as Liquid Chromatography-Mass Spectrometry (LC-MS/MS) and Ion Chromatography-High-Resolution Mass Spectrometry (IC-HRMS) were employed for method validation and monitoring across 97 honey samples. The extraction procedure was optimized, and the validation procedure followed EU Regulation 808/2021 and SANTE 11312/2021 guidelines. LC-MS/MS and IC-HRMS demonstrated comparability and high sensitivity, with RSDr and RSDR values falling within the range of 3%–18% and 6%–22%, respectively, for all analytes considered except for AMPA. AMPA showed CV% values > 25% at the concentration of 5 and 10 ng/g in LC–MS/MS. For IC-HRMS RSDr and RSDR values for all analytes fall within the 3%–14% and 4%–14% range, respectively. Glyphosate was quantified in 12% of the samples, with one sample exceeding Maximum Residue Level (MRL). Glufosinate and its metabolites were not detected in any of the samples.

Linkage between glyphosate adsorption/desorption and mineralization in Central European agricultural soils

The pesticides bioavailability in soil is primarily governed by sorption behaviors of soil. This study aimed to study adsorption, desorption, and bioavailability of glyphosate in agricultural soils and to find relationships to its mineralization. We examined 21 soil samples from Germany and Slovenia, varied widely in soil texture (8–86% sand), soil organic matter (1.2–4.5%), pH (5.0–7.1), exchangeable ions (7.5–32.9 mmolc 100 g−1) parameters. A batch experiment based on OECD guideline 106 was utilized to assess adsorption/desorption characteristics in soil of the herbicide glyphosate. Experimental results indicated that glyphosate was strongly adsorbed (77 and 100%) at Kelheim and Brezje soils, and weakly desorbed (5.7 and 49.0 %) at Brezje and Skrinjar soils, respectively. A significant variance in glyphosate mineralization was observed across different soils. Among evaluated parameters, exchangeable acidity was found to be the primary factor influencing adsorption and desorption of glyphosate, revealing a significant negative correlation at p < 0.0001. Additionally, a statistically significant relationship (R2 = 0.5299 at p = 0.0002) was obtained between adsorption/desorption and mineralization in soils of glyphosate herbicide. The study revealed that adsorption/desorption of glyphosate is heavily influenced by exchangeable acidity, and the mineralization of glyphosate is closely tied to a soil's capacity for glyphosate adsorption/desorption.

High-performing structural optimization of graphene quantum dots as glyphosate herbicide photoluminescent probes: real case studies and mechanism insights

The widespread usage of the herbicide glyphosate calls for urgent action, aiming at the development of new, simple, low-cost, and eco-friendly detection approaches. In the last decade, investigation of graphene quantum dots (GQDs) as potential optical probes for various pollutants rapidly grew, thanks to their easy-manipulative structure, remarkable photoluminescence (PL) in the visible part of the spectrum, good dispersibility, biocompatibility, and non-toxicity, as well. Herein, a fast, simple, and environmentally friendly method for GQDs structural modification is presented. GQDs raw powder was exposed to γ- rays at three different doses (100, 200, and 300 kGy) in air, without any solvent or reagents. Irradiation of dots under such affordable conditions led to the additional incorporation of oxygen-containing moieties in the GQD structure. For the first time, oxygen-rich GQDs irradiated at a 300 kGy dose were successfully applied as direct turn-off PL probe for glyphosate detection. The high coefficient of determination (R-squared (R2) = 0.99) and very low limit of detection (3.02 μmol L-1) reveal good linearity between the potential sensor and analyte, as well as sensitivity. Glyphosate was successfully detected in celery samples, with a recovery value of 107 ± 0.85%. To evaluate the biological safety of the proposed sensing probe, [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) and the hemolysis assays were performed. Obtained results show that irradiated and non-irradiated GQDs did not cause the death of MRC-5 cells, and hemolysis of erythrocytes. The obtained results demonstrate that GQDs irradiated in an air medium can be potentially applied for glyphosate detection.