Concentrations Of Glyphosate Research Articles

Acute and Chronic Effects of a Glyphosate and a Cypermethrin-Based Pesticide on a Non-Target Species Eucypris sp. Vavra, 1891 (Crustacea, Ostracoda)

Ostracoda species are indicators of their current and past environment (paleoenvironment). The study aims to evaluate the acute and chronic sensitivities of a freshwater ostracod species (Eucypris sp.) to agricultural pesticides (a cypermethrin-based insecticide and a glyphosate herbicide-based formulation). Lethal concentrations (LC50) of each pesticide for the species at 24 and 48 h were determined. The chronic exposure allowed assessing the effects of low concentrations of both pesticides; firstly, on the parthenogenetic reproduction of Eucypris sp., and, secondly, on its population growth. Then, individuals of Eucypris sp. were exposed to 0.536 ppb and 1.072 ppb of cypermethrin and 4.51 ppm and 9.03 ppm of glyphosate. These concentrations are respectively the 10%, and the 20% of the 48-h LC50 (median lethal concentration) of both pesticides for the species. The estimated 24-h LC50 of cypermethrin was 7.287 ppb. At 48-h, it was 5.361 ppb. For glyphosate, the 24-h LC50 was 50.521 ppm, while at 48-h it was 45.149 ppm. After 10 days of exposure to low concentrations of cypermehrin, only 30% of females reproduced parthenogenetically with 10% and 20% of LC50-48-h. For the control treatment, reproduction in 80% of females was observed. Eucypris sp. population growth after 28 days of exposure to low concentrations of cypermethrin showed significant retardation. Regarding glyphosate chronic exposure, 60%, 50%, and 90% of individuals were able to reproduce at 10% of LC50-48-h, 20% LC50-48-h, and the control treatment, respectively. The population growth was also affected by the tested low concentrations of glyphosate. The study showed high sensitivity of Eucypris sp. to cypermethrin compared to glyphosate. However, low concentrations of both pesticides affected the species at individual and population level.

Development of a sensitive direct injection LC-MS/MS method for the detection of glyphosate and aminomethylphosphonic acid (AMPA) in hard waters.

Glyphosate is currently the most widely used herbicide in the world; however, the zwitterionic and highly polar properties of glyphosate make current pesticide analysis methods unsuitable for its trace analysis in natural waters. Additionally, current glyphosate analysis methods do not account for waters of varying hardness, which is vital as glyphosate can complex with cationic species such as Ca2+ and Mg2+ in the environment. We detail here a robust LC-MS/MS method for the quantitation of glyphosate and its primary transformation product aminomethylphosphonic acid (AMPA) in environmental waters of varying water hardness. Chromatographic separation was achieved with a reversed-phase and weak anion-exchange mixed-mode column. We found that the addition of EDTA into hard water samples increases the response of both glyphosate and AMPA in the mass spectrometer. Limits of detection of 0.23 and 0.30μgL-1 for glyphosate and AMPA in EDTA-amended hard water were achieved, respectively. We have demonstrated that the accuracy of the method was consistent over a wide range of water hardness levels up to a maximum of ~340mgmL-1 CaCO3 hardness. We validated the method using matrix fortification of uncontaminated environmental samples from US river water. We then demonstrated that the method was successful at quantifying glyphosate and AMPA across surface and drinking water samples of varying water hardness from North Carolina and Sri Lanka. Measured concentrations of glyphosate and AMPA ranged from 1.6 to 13μgL-1 and 0.50 to 2.5μgL-1, respectively. This study represents a significant increase in sensitivity for LC-MS/MS analysis of glyphosate in hard water systems. Graphical abstract.

Impact of Environmentally Relevant Concentrations of Glyphosate and 2,4-D Commercial Formulations on Nostoc sp. N1 and Oryza sativa L. Rice Seedlings

Wide applications of glyphosate and 2,4-dichlorophenoxyacetic acid (2,4-D) in rice paddy fields could lead to their residues in environment, posing adverse effects on rice growth and primary producers in the rice ecosystem. This research aims to determine the effects of environmentally relevant concentrations of glyphosate and 2,4-D commercial formulations on Nostoc sp. N1 and rice seedlings. The effects of herbicides on Nostoc sp. N1 were measured from the growth and acute toxicity. The germination and growth were used to determine the effects of herbicides on rice seedlings by measuring their physical and biochemical characteristics. Results showed that while glyphosate had higher toxicity than 2,4-D, both herbicides could stimulate the growth of Nostoc sp. N1 as indicated by their increase in biomass and chlorophyll a content. In Petri dish experiments, Nostoc sp. N1 cells not only promoted the germination of rice seedlings when added alone, but they also alleviated the toxicity of both herbicides to the rice seedlings. In pot experiments, the addition of Nostoc sp. N1 cells combined with herbicides promoted the biochemical characteristics of the rice seedlings by increasing the total chlorophyll, carotenoid and total amino acid content. Our results suggested that environmentally relevant concentrations of glyphosate and 2,4-D formulations should not pose any adverse effects on Nostoc sp. N1. Also, with their toxicity-mitigating and growth-promoting effects on rice seedlings, Nostoc sp. N1 cells could be applied in the alleviation of herbicide residue toxicity in paddy fields.

Characterization of a Glyphosate-Tolerant Enzyme from Streptomyces svecius: A Distinct Class of 5-Enolpyruvylshikimate-3-phosphate Synthases.

Natural and modified versions of the 5-enolpyruvylshikimate-3-phosphate synthase (epsps) gene have been used to confer tolerance to the broad-spectrum herbicide glyphosate in a variety of commercial crops. The most widely utilized trait was obtained from the Agrobacterium tumefaciens strain CP4 and has been commercialized in several glyphosate-tolerant crops. The EPSPS gene products are enzymes that have been divided into three classes based on sequence similarity, sensitivity to glyphosate, and steady-state catalytic parameters. Herein, we describe the informatics-guided identification and biochemical and structural characterization of a novel EPSPS from Streptomyces sviceus (DGT-28 EPSPS). The data suggest DGT-28 EPSPS and other closely related homologues exemplify a distinct new class (Class IV) of EPSPS enzymes that display intrinsic tolerance to high concentrations of glyphosate (Ki ≥ 5000 μM). We further demonstrate that dgt-28 epsps, when transformed into stable plants, provides robust (≥4× field rates) vegetative/reproductive herbicide tolerance and has utility in weed-control systems comparable to that of commercialized events.

Efectos de metales pesados, glifosato y sus mezclas binarias sobre el crecimiento de algas verdes

Rivers and streams of rural areas of the Buenos Aires Province contain variable concentrations of heavy metals and glyphosate. In this study, the toxicity of the metals Cu, Pb and Zn, the herbicide glyphosate (active product and ATANOR® formulation) and their binary combinations, was assessed on two green algae species (the standard species Raphidocelis subcapitata and a native strain of Scenedesmus acutus isolated from Burgos Stream [Buenos Aires]). The bioassays were carried out applying a concentration range of 0.5 mg/L - 20 mg/L, in incubations lasting 7 days after which the algal density was estimated. To obtain the effective concentrations inhibiting 10, 20 and 50% of the growth (EC10, EC20 and EC50) of individual substances and their combinations, the percentage of growth inhibition (%I) was modeled as a function of each concentration by a nonlinear fit. According to the EC50 obtained for each species, the toxicity of Cu and Zn was higher in R. subcapitata (7.47±2.14 and 6.51±2.26 mg/L, respectively) than in S. acutus (10.90±3.75 and> 20 mg/L), while Pb and glyphosate active compound were not toxic for neither of the two strains. ATANOR® glyphosate was toxic only to R. subcapitata (EC50=12.00±3.10 mg/L). According to the EC10 and EC20 values of the individual substances and the binary combinations, S. acutus showed higher sensitivity than R. subcapitata. From the analysis of toxic units (TU), the combinations Cu+Zn, Cu+glyphosate ATANOR® and Zn+glyphosate ATANOR® showed antagonistic effects on R. subcapitata (according to the TU values obtained from EC20 and EC50), while the Cu+Pb and Cu+Zn combinations showed synergistic and antagonistic effects, respectively, on S. acutus (according to the TU values obtained from the EC20). These results highlight the importance of conducting bioassays of toxic substances using native algal strains which allow inferring potential effects in native communities and food webs.

Toxicity response of Chlorella microalgae to glyphosate herbicide exposure based on biomass, pigment contents and photosynthetic efficiency

The extensive use of glyphosate (N-(phosphonomethyl) glycine) herbicide in agriculture is accompanied by the risk of environmental contamination of aquatic ecosystems. In this study, the effects of glyphosate at different concentrations (50–500 µg ml-1) on three Chlorella species including Chlorella ellipsoidea, Chlorella sorokiniana and Chlorella vulgaris especially in relation to the biomass, pigment contents and photosynthetic efficiency were assessed. After treatment for 24 hr, the acute toxicity results showed that C. vulgaris (IC50 = 449.34 ± 6.20 µg ml-1) was more tolerant to glyphosate than C. ellipsoidea (IC50 = 288.23 ± 23.53 µg ml-1) and C. sorokiniana (IC50 = 174.28 ± 0.50 µg ml-1). After a 72-hr chronic toxicity treatment with glyphosate, glyphosate concentrations decreased to 400–500 µg ml-1 in C. ellipsoidea, 200–300 µg ml-1 in C. sorokiniana and 200–500 µg ml-1 in C. vulgaris respectively. During 24-hr acute toxicity exposure to glyphosate, the pigment contents and maximum quantum efficiency of photosystem II (Fv/Fm) decreased as the concentration of glyphosate increased. Overall, the biomass, pigment contents and photosynthetic efficiency presented a high positive correlation. It is worthwhile to mention that our study provides detailed information on the toxicity and sensitivity of these Chlorella species to glyphosate.

Glyphosate-remediation potential of selected plant species in artificial wetlands

Glyphosate is a systemic herbicide with an important environmental impact due to its adverse effect on non-target organisms. Its removal can be accomplished by wild (native) plants which, together with their associated microbiota, have acquired tolerance against glyphosate or are able to degrade it. Little is known, however, about these plants' potential for glyphosate remediation and the role that plant-microbe interactions play in this process. The objective of the present study was to evaluate plant species from locations with a history of glyphosate exposure – drainage ditches of banana plantations (Musa sp.), or riparian areas - to determine which, in combination with their microbiota, promote the removal of glyphosate. Five plant species were selected to evaluate their response to inundated growing conditions and exposure to 20 mg glyphosate acid equivalent/L for 47 days. Parameters affecting plant growth and glyphosate removal were recorded. Rhizosphere bacterial strains were identified and their tolerance to different glyphosate concentrations determined. Also, the activity of 19 rhizospheric enzymes associated with the phosphorus, carbon and nitrogen cycles were analyzed. Glyphosate-treated Panicum maximum exhibited the highest removal efficiency (87%), followed by Typha domingensis and Heliconia latispatha. All plants were associated with glyphosate-tolerant bacteria, and in the cases of Xanthosoma sagittifolium and Fimbristylis dichotoma, strains were recovered that even succeeded in growing in a medium containing 40 g glyphosate ae/L. Processes involved in carbon, nitrogen and phosphorus metabolism in the rhizosphere were affected by glyphosate exposure, and the importance of plant-microbe-substrate interactions in the elimination of glyphosate was evinced. Although all plants contributed to the removal of glyphosate, their use in phytoremediation projects will depend on the location and nature of the environmental problem to be resolved.

Effects of glyphosate spray-drift on plant flowering.

Recent studies have shown that sub-lethal doses of herbicides may affect plant flowering, however, no study has established a direct relationship between the concentrations of deposited herbicide and plant flowering. Here the aim was to investigate the relationship between herbicide spray drift deposited on non-target plants and plant flowering in a realistic agro-ecosystem setting. The concentrations of the herbicide glyphosate deposited on plants were estimated by measuring the concentration of a dye tracer applied together with the herbicide. The estimated maximal and average deposition of glyphosate within the experimental area corresponded to 30g glyphosate/ha (2.08% of the label rate of 1440g a.i./ha) and 2.4g glyphosate/ha (0.15% label rate), respectively, and the concentrations decreased rapidly with increasing distance from the spraying track. However, there were not a unique relation between distance and deposition, which indicate that heterogeneities of turbulence, wind speed and/or direction can strongly influence the deposition from 1min to another during spraying. The effects of glyphosate on cumulative flower numbers and flowering time were modelled using Gompertz growth models on four non-target species. Glyphosate had a significantly negative effect on the cumulative number of flowers on Trifolium pratense and Lotus corniculatus, whereas there were no significant effects on Trifolium repens, and a positive, but non-significant, effect on number of flowers on Cichorium intybus. Glyphosate did not affect the flowering time of any of the four species significantly. Lack of floral resources is known to be of major importance for pollinator declines. The implications of the presented results for pesticide risk assessment are discussed.

Isolated and combined effects of glyphosate and its by-product aminomethylphosphonic acid on the physiology and water remediation capacity of Salvinia molesta

We evaluate the isolated and combined effects of glyphosate and its by-product aminomethylphosphonic acid (AMPA) and the potential of the aquatic macrophyte Salvinia molesta to remove these chemicals from contaminated water. Plants were exposed to environmentally relevant concentrations of glyphosate (0, 20, 40, 60, 80 and 100 µg l−1) or AMPA (0, 10, 20, 30, 40 and 50 µg l−1) for seven days. Then, based on the effective concentrations of glyphosate found to reduce photosynthetic rates by 10% (EC10) and 50% (EC50), the plants were exposed to combinations of 0, 16 and 63.5 µg glyphosate l−1 and 0, 5, 15, 25 µg AMPA l−1. The EC(10) and EC(50) were lower for AMPA (6.1 µg l−1 and 28.4 µg l−1 respectively) than for glyphosate (16 and 63.5 µg glyphosate l−1 respectively). When occurring together, the deleterious effects of those chemicals to plants increased. S. molesta plants removed up to 74.15% of glyphosate and 71.34% of AMPA from culture water. Due to its high removal efficiency, S. molesta can be used in phytoremediation programs. It will be important to evaluate the combined effects of glyphosate and AMPA in any toxicological studies of the herbicide.

Chronic exposure to glyphosate in Florida manatee

Florida manatees depend on freshwater environments as a source of drinking water and as warm-water refuges. These freshwater environments are in direct contact with human activities where glyphosate-based herbicides are being used. Glyphosate is the most used herbicide worldwide and it is intensively used in Florida as a sugarcane ripener and to control invasive aquatic plants. The objective of the present study was to determine the concentration of glyphosate and its breakdown product, aminomethylphosphonic acid (AMPA), in Florida manatee plasma and assess their exposure to manatees seeking a warm-water refuge in Crystal River (west central Florida), and in South Florida. We analyzed glyphosate’s and AMPA’s concentrations in Florida manatee plasma (n = 105) collected during 2009–2019 using HPLC-MS/MS. We sampled eight Florida water bodies between 2019 and 2020, three times a year: before, during and after the sugarcane harvest using grab samples and molecular imprinted passive Polar Organic Chemical Integrative Samplers (MIP-POCIS). Glyphosate was present in 55.8% of the sampled Florida manatees’ plasma. The concentration of glyphosate has significantly increased in Florida manatee samples from 2009 until 2019. Glyphosate and AMPA were ubiquitous in water bodies. The concentration of glyphosate and AMPA was higher in South Florida than in Crystal River, particularly before and during the sugarcane harvest when Florida manatees depend on warm water refuges. Based on our results, Florida manatees were chronically exposed to glyphosate and AMPA, during and beyond the glyphosate applications to sugarcane, possibly associated with multiple uses of glyphosate-based herbicides for other crops or to control aquatic weeds. This chronic exposure in Florida water bodies may have consequences for Florida manatees’ immune and renal systems which may further be compounded by other environmental exposures such as red tide or cold stress.

Effects of microplastics and glyphosate on growth rate, morphological plasticity, photosynthesis, and oxidative stress in the aquatic species Salvinia cucullata.

Glyphosate and microplastics are widely found in marine, terrestrial, and freshwater environments due to their globally widespread application. Further, they have proved to have specific ecotoxicity effects on aquatic plants. However, few studies have focused on the effects of small plastic particles and glyphosate, or especially, their combined effect on vascular plants in freshwater ecosystems. This study aimed to conduct a simulated greenhouse experiment to investigate the ecotoxicity of polystyrene microplastics and glyphosate on the floating plant Salvinia cucullata by exposure to fluorescent polystyrene microplastics (1μm; concentration, 3, 15, and 75mg/L), glyphosate (5, 25, and 50mg/L), and a mixture of the two (3+5, 15+25, and 75+50mg/L) for seven days. Glyphosate significantly reduced the relative growth rate, photosynthetic capacity, and root activity of S.cucullata. Polystyrene microplastics did not significantly influence photosynthesis or leaf morphological characteristics but they significantly reduced relative growth rate and root activity in S.cucullata, indicating that the effects of microplastics on aquatic plants are potentially associated with different organs exposed to pollution. Polystyrene microplastics and glyphosate activated the plant antioxidant defense systems by increasing antioxidative enzyme activities including, superoxide dismutase, ascorbate peroxidase, and catalase to cope with oxidative stress. Synergistic effects (only observed in percent leaf yellowing) were observed when S.cucullata was exposed to a high concentrations (≥15+25mg/L) of glyphosate and microplastics. Our results indicate that pervasive microplastics and herbicide contamination in freshwater may potentially affect the growth of aquatic plants.

Confirmation of Multiple Resistant Chloris radiata Population, Harvested in Colombian Rice Fields

This paper reports the first C. radiata population with resistance to glyphosate and multiple resistance to the acetolactate synthase (ALS) inhibitor, imazamox. Two populations, one putative resistant (R) and one susceptible (S), were used in the studies. Dose–response experiments were performed to evaluate the resistance factor (RF). Shikimic acid accumulation, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) and ALS enzyme activities were studied together with chemical integrated weed management (adjuvants and alternative herbicides). The resistance to glyphosate and imazamox was confirmed based on the dry weight reduction, visual evaluation and survival. The results of dose–response curve assays showed for the R population intermedium RF for glyphosate (5.1 and 9.7 for amount of herbicide needed to reduce the dry weight by 50% GR50 and lethal dose of 50% LD50, respectively) and high RF for imazamox (34.9 and 37.4, respectively). The low shikimic acid accumulation in R population confirmed the glyphosate resistance. The glyphosate concentration which inhibited the EPSPS enzyme in 50% (I50) was approximately 20 times higher for R population than the S population, while the imazamox I50 in ALS enzyme for the R plants was 89 times greater than the S plants. In the chemical integrated weed management, the foliar retention and effectivity assays showed that the use of adjuvants improves the retention of glyphosate and imazamox, and the reduction in dry weight of weeds. The alternative herbicides study showed that the acetyl-CoA carboxylase (ACCase) inhibitors, paraquat and glufosinate, had better results for control in this species. However, poor control was observed with bispyribac-sodium, metsulfuron-methyl and quinclorac, indicating possible cross-resistance for ALS-inhibitors and also multiple resistance for auxinic herbicides (quinclorac). Nevertheless dose–response experiments are required to confirm this assumption.

Evidence for soil pesticide contamination of an agroecological farm from a neighboring chemical-based production system

The global chemical-based agriculture (CBA) production system brought social and environmental consequences such as the contamination of soils, waters, bottom sediments and food, as well as negative effects on non-target species. As an alternative, a new paradigm emerged: agroecology-based agriculture (ABA), based on ecosystem services and the reduction of chemical inputs. More and more establishments have adopted this form of production; however, they are located next to crops to which pesticides are applied. The objective of this work was to study, through the spatio-temporal characterizations of pesticides in soils, how an ABA production system can be affected by the CBA fields around it. Two sampling campaigns were conducted and soil samples were obtained from "La Aurora", an agricultural establishment located in the Argentine pampa and recognized by the FAO for its agroecological practices, and from neighboring fields with CBA productions. The samples were tested for 19 herbicides (including 3 metabolites) and 3 fungicides by UPLC-MS/MS, of which we detected glyphosate and its metabolite AMPA, 2,4-D, atrazine, acetochlor, metsulfuron-methyl, desethyl-atrazine, epoxiconazole, and tebuconazole. Three or more pesticides co-occurred in 93% and 32% of the CBA and ABA samples, respectively. Glyphosate and AMPA, with the highest detection frequency, also accounted for 90% of the total pesticide load in both systems. The maximum concentrations (μg kg−1 dry weight) in the CBA/ABA fields, respectively, were glyphosate (1268.92/98.93), AMPA (2919.17/114.01), followed by 2,4-D (38.52/31.12), and epoxiconazole (13.35/18.41). No significant temporal differences were found in glyphosate concentration within each establishment, corroborating its pseudo-persistence in CBA establishments, and establishing it in ABA field. Moreover, glyphosate was found in the ABA field more than 300 m from the limit with the CBA fields. Glyphosate and AMPA concentrations are in the order of those reported to cause sublethal and lethal effects in soil organisms. These results highlight the mobility of pesticides, as the ABA establishment is affected by its surroundings where pesticides are used, even at sites far from the interface between them. Given their higher detection frequencies and environmental concentrations in comparison to the other pesticides, glyphosate and AMPA are proposed as environmental tracers of conventional agroproductive activities.

Glyphosate-based herbicides affect behavioural patterns of the livebearer Jenynsia multidentata.

Roundup® is one of the most widely marketed glyphosate-based herbicides in the world. There are many different formulations of this brand that differ from each other in glyphosate concentration, salts and adjuvants, including surfactants, which are labelled as "inert" compounds. Several studies have shown that these formulations are highly toxic to fish, even compared with pure glyphosate. However, mechanisms underlying this toxicity are not fully understood. In this context, this study evaluated the effects of exposure to Roundup Original® (RO), Roundup Transorb® (RT), and Roundup WG® (RWG) on the behavioural patterns of the livebearer Jenynsia multidentata. This fish naturally inhabits agricultural areas in southern Brazil and Argentina where glyphosate is used extensively. In the experiment, animals were exposed to the herbicides for 96 h, at the environmentally relevant concentration of 0.5 mg/L of glyphosate. Swimming performance, anxiety, aggressiveness, long-term memory and male sexual activity were recorded. The formulation RWG negatively affected swimming performance, thigmotaxia and long-term memory consolidation. Conversely, RT reduced the sexual performance of males. These results confirm that Roundup® formulations are extremely harmful and also that they have different targets of toxicity, affecting behaviours that are essential for fish survival.

On the efficient removal, regeneration and reuse of quaternary chitosan magnetite nanosorbents for glyphosate herbicide in water

In this study, magnetic nanosorbents consisting of magnetite (Fe3O4) cores coated with trimethyl chitosan (TMC)-silica hybrid shells were synthesized using a one-step coating procedure, and their application in the adsorptive removal of glyphosate (GLY) from artificial (ultra-pure) and real water (wastewater) samples was investigated. In synthetic laboratory samples, the magnetic nanosorbents decreased realistic environmental concentrations of GLY to values that are below the maximum permissible value (0.1 μg/L) defined by the European Directive of Drinking Water. In spiked wastewater samples, the nanosorbents at a dose of 2.5 mg/mL removed 76.8% of the GLY (initial concentration of 3.0 μg/L), demonstrating the potential application of these nanosorbents in aqueous matrices of complex nature. The adsorption performance towards GLY was assessed by varying the operational conditions in ultra-pure water, including initial GLY concentration, pH, contact time and sorbent dose. The magnetic nanosorbent showed fast adsorption of GLY, with the maximum adsorption being reached within 60 min contact time attaining a maximum of 97% removal for the GLY concentrations tested. The kinetic data were consistent with the pseudo-first-order model. The equilibrium sorption data was better described by Sips model, with a maximum adsorption capacity of 3.04 mg/g. The magnetic nanosorbents could be reused after regeneration and the removal of GLY remained above 80% after 4 adsorption-desorption cycles. Our results indicate that assisted magnetic water remediation using recyclable TMC surface-modified nanosorbents is an efficient process for the elimination of glyphosate from ultra-pure water and real wastewater to meet water quality standards.

Use of Dielectric Spectroscopy for the Study of Concentration of Glyphosate in Distilled Water

In this paper, the capability of sensing low concentrations of glyphosate in water of two interdigital capacitive transducers are analyzed using numerical simulations and measurements. Each microwave sensor is analyzed using the surface electric field produced at the resonance frequency. In addition, the reflection coefficient of each transducer submerged in water with glyphosate is measured and compared with distilled water. Prepared samples with concentrations of 1ppm/L (1 part per million over a liter of distilled water) are used for the experimental tests.

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

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

In vivo and in vitro evaluation of the effect of glyphosate (Roundup) on Toxoplasma gondii.

Apicoplast, a derived non-photosynthetic plastid, which is found in most Apicomplexa, provides essential functions to parasites. The shikimate pathway is localized in the plant chloroplast as a remarkable route for the survival of the Toxoplasma. In this study, in vivo and in vitro effects of glyphosate (Roundup, Herbicide), as an inhibitor of the enzyme, were evaluated on T. gondii. Tachyzoites of RH strain were incubated for 1.5h in various concentrations (1-128µg/ml) of glyphosate. The parasite was cultivated in the cell monolayer of the heLa cell, and then the cultures were exposed to various concentrations. To evaluate the therapeutic quality, 2 × 105 tachyzoites were intradermally inoculated into ten mice from each group. Four doses of the compound were daily administrated every 24h after inoculation due 10days continuously. Also, two other groups were assigned as the positive and negative control. In flow cytometry, the highest mortality rate was related to concentrations of 128 and 256μg/ml, 18.29% and 18.64%, respectively, while the mortality rate was 0.03% in the negative control (P value > 0.05). Based on microscopic observation of the stained touch smear of the liver, all treated mice were killed by the parasite. This compound also had no lethal effect on the mice. According to the results of this study, glyphosate is not a good candidate for the treatment of toxoplasmosis. It seems that the parasite has another pathway for providing the essential amino acids.

Assessing glyphosate concentrations in six reservoirs of Paraíba do Sul and Guandu River Basins in southeast Brazil

Glyphosate is a popular herbicide used worldwide, and several studies consider it to be an environmental hazard affecting human health. The present study aimed to detect glyphosate in six different reservoirs of Paraíba do Sul and Guandu River Basins in Southeast Brazil, used for multiple purposes, including fishery activities and domestic water supply. Ion chromatography was used to analyze the water samples, as it is a fast and environmentally friendly technique to detect glyphosate. Our results revealed that, despite differences related to trophic state, season of the year or distance to urban areas, glyphosate was detected in all reservoirs and in three of them with concentrations above the limit imposed by Brazilian legislation. Among the environmental variables studied, turbidity presented the highest correlation with glyphosate concentrations. The effect of rainfall increasing turbidity in the rivers reinforces the importance of draining waters from surrounding areas that transport glyphosate into the aquatic ecosystems. The detection of the herbicide in the various systems confirms the wide use of this compound in the drainage basins of the studied reservoirs and highlights the importance of water monitoring. Further, the results reveal how urgent and important it is to explore through laboratory experiments the pathways of degradation of this herbicide in tropical and subtropical aquatic environments together with its effects on flora and fauna.

Pesticide Contamination in Drinking and Surface Water in the Cienega, Jalisco, Mexico

Sixty percent of global agricultural production depends on the use of pesticides, despite their adverse effects on human health and the ecosystem. In Mexico, the application of these products has been exacerbated, including pesticides already banned in other countries. The objective of this study was to determine pesticide concentrations in samples of water purification plants and surface water from the Cienega area of Jalisco, Mexico. A survey of 119 farmers with occupational exposure to pesticides was carried out in order to obtain information on the most frequently used pesticides. Subsequently, 51 samples taken at 7 different sites were analyzed using liquid chromatography and mass-mass spectrometry. The most frequently used pesticides were organophosphates (28.87%), pyrethroids (12.89%), and the herbicide paraquat (31.95%). In surface water, the prevalent pesticides were glyphosate (56.96–510.46 ppb) and malathion (311.76–863.49 ppb). Glyphosate levels were higher than the limits acceptable in daily water intake in Cumuato. Malathion levels exceeded the limits permissible by EPA in water purification plants in urban public establishments (100 ppb for children, and 200 ppb for adults). In addition, a multidimensional scaling analysis showed that the sampled sites could be grouped into 2 different bodies of water, based on similarities in their glyphosate concentrations (stress = 0.005), while the concentrations of malathion were heterogeneous (stress = 0.001).