Concentrations Of Glyphosate Research Articles

Associations of glyphosate exposure and serum sex steroid hormones among 6–19-year-old children and adolescents

Glyphosate, ranked as one of the most widely used herbicides in the world, has raised concerns about its potential disruptive effects on sex hormones. However, limited human evidence was available, especially for children and adolescents. The present study aimed to examine the associations between exposure to glyphosate and sex hormones among participants aged 6–19 years, utilizing data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2013 and 2016. Children and adolescents who had available data on urinary glyphosate, serum sex steroid hormones, including testosterone (TT), estradiol (E2) and sex hormone binding globulin (SHBG), and covariates were selected. Additionally, the ratio of TT to E2 (TT/E2) and the free androgen index (FAI), which was calculated using TT/SHBG, were also included as sex hormone indicators. Survey regression statistical modeling was used to examine the associations between urinary glyphosate concentration and sex hormone indicators by age and sex group. Among the 964 participants, 83.71% had been exposed to glyphosate (>lower limit of detection). The survey regression revealed a marginally negative association between urinary glyphosate and E2 in the overall population, while this association was more pronounced in adolescents with a significant trend. In further sex-stratified analyses among adolescents, a significant decrease in E2, FAI, and TT (p trend <0.05) was observed in female adolescents for the highest quartile of urinary glyphosate compared to the lowest quartile. However, no similar association was observed among male adolescents. Our findings suggest that exposure to glyphosate at the current level may decrease the levels of sex steroids in adolescents, particularly female adolescents. Considering the cross-sectional study design, further research is needed to confirm our findings.

Association between glyphosate exposure and osteoarthritis in US adults: Especially in people who are obese and inactive in leisure time physical activity

ObjectiveLittle has been known on the effect of chronic glyphosate exposure on osteoarthritis (OA). The aim of this study was to investigate the association between glyphosate exposure and OA and to further investigate the different moderating effects of leisure time physical activity (LTPA) and body mass index (BMI) types on the association between glyphosate exposure and OA. MethodsCross-sectional data from 2540 participants in the 2015–2018 National Health and Nutrition Examination Survey (NHANES) were used to explore the association between glyphosate exposure and OA. Multivariate logistic regression models and restricted cubic spline models were used to investigate the association between glyphosate exposure and OA, and further analyses were conducted to determine the association between glyphosate exposure and OA under different LTPA and BMI types. ResultsOf the 2540 participants, 346 had OA. Participants with the highest glyphosate concentration (Q4) had a higher incidence of OA compared to participants with the lowest glyphosate concentration (Q1) (OR, 1.88; 95 % confidence interval [CI]: 1.13, 3.13), there was no nonlinear association between glyphosate and OA (non-linear P = 0.343). In the no LTPA group, glyphosate concentration in the Q4 group was correlated with OA (OR, 2.65; 95%CI: 1.27, 5.51). In the obese group, glyphosate concentration in the Q4 group was correlated with OA (OR, 2.74; 95 % CI: 1.48, 5.07). Among people with high BMI and inactive in LTPA, glyphosate concentrations in Q4 were associated with OA (OR, 2.19; 95 % CI: 1.07, 4.48). ConclusionsGlyphosate is associated with OA odd, and physical activity and moderate weight loss can mitigate this association to some degree. This study provides a scientific basis for rational prevention of OA by regulation of LTPA and BMI under glyphosate exposure.

Modeling pesticides and ecotoxicological risk assessment in an intermittent river using SWAT

The present work aimed to predict the fate of two pesticides, copper (Cu) and glyphosate in a Mediterranean basin with an intermittent river and to assess the ecotoxicological risk related to their presence in water bodies coupling field measurements of streamflow and pesticide concentrations, and an eco-hydrological model. The Soil and Water Assessment Tool (SWAT) model was calibrated and, subsequently used to assess predicted environmental concentrations of pesticides in surface waters. The ecotoxicological risk related to the presence of Cu and glyphosate in surface water was assessed at the reach scale by using the Toxicity to Exposure Ratio approach (TER). Measurements of glyphosate concentrations (< 0.5 μg l−1) exceeded the maximum European threshold of environmental quality standards for pesticides (EQS) of 0.1 μg l−1. High concentrations of glyphosate were predicted in the wet season and in September, when glyphosate is mostly used in vineyards and olive grove productions. Acute risk (TER < 100) associated with the presence of glyphosate was detected for several reaches. High concentrations of Cu (< 6.5 μg l−1), mainly used as a fungicide in vineyards, were predicted in several river reaches. The results of the ecotoxicological risk assessment revealed that November and January were the critical months during which most of the river reaches showed a chronic risk associated with the presence of Cu.

Assessing the Profile of Glyphosate Residues in Maize Grains Sold in the Federal Capital Territory Abuja, Nigeria

The profile of glyphosate residues in maize grains sold in the Federal Capital Territory Abuja (FCT), Nigeria was assessed. Methods Twenty-six maize grains samples of yellow and white morphotypes were collected from some selected markets within the FCT, Abuja. Analytical methods on the pulverized maize grains included solvent extraction using (acetonitrile/water (55:45), clean-up of pesticide residues and their quantification by HPLC/UV as described by AOAC - QuEChERS method. Results The results showed that the mean concentration of glyphosate in the maize grains ranged from 0 to 24.30 ± 0.002 mgkg_1 with a mean glyphosate concentration of 3.474 mgkg-1 was detected. Four samples representing 17.86% of the samples collected violated WHO/FAO CODEX standard of 5.0 mgkg-1 while values recorded for Acceptable Daily Intake (ADI) for all the samples were within an acceptable limit of 0 - 1 mgkg-1. Heath risk index values were &lt;1 suggesting that the consumer populations were not at risk. Conclusion The high profile of glyphosate residue in maize grains from Gwagwalada Area Council of the FCT is of great concern and needed to be further investigated HIGHLIGHTS Maize grains had a low glyphosate residue contamination rate of 96.15% in the FCT, Nigeria. The concentration rate of glyphosate residue in the maize grains range was 0 - 24.3mg/kg Yellow maize grains from Gwagwalada Area Councils had the highest mean concentration of glyphosate residue. Four samples i.e. 15.38% of the maize grains violated the CODEX Maximum Residual limit. The Health Index (HI) for all the maize grains was ˂ 1 and signified no associated risk

Glyphosate exposure, muscular health and functional limitations in middle-aged and older adults

BackgroundGlyphosate is the most widely used herbicide worldwide, both in domestic and industrial settings. Experimental research in animal models has demonstrated changes in muscle physiology and reduced contractile strength associated with glyphosate exposure, while epidemiological studies have shown associations between glyphosate exposure and adverse health outcomes in critical biological systems affecting muscle function. MethodsThis study used data from a nationally representative survey of the non-institutionalized U.S. general population (NHANES, n = 2132). Urine glyphosate concentrations were determined by ion chromatography with tandem mass spectrometry. Hand grip strength (HGS) was measured using a Takei Dynamometer, and relative strength estimated as the ratio between HGS in the dominant hand and the appendicular lean mass (ALM) to body mass index (ALMBMI) ratio. Low HGS and low relative HGS were defined as 1 sex-, age- and race-specific SD below the mean. Physical function limitations were identified as significant difficulty or incapacity in various activities. ResultsIn fully-adjusted models, the Mean Differences (MD) and 95% confidence intervals [95%CI] per doubling increase in glyphosate concentrations were −0.55 [-1.09, −0.01] kg for HGS in the dominant hand, and −0.90 [-1.58. −0.21] kg for HGS/ALMBMI. The Odds Ratios (OR) [95% CI] for low HGS, low relative HGS and functional limitations by glyphosate concentrations were 1.27 [1.03, 1.57] for low HGS; 1.43 [1.05; 1.94] for low relative HGS; 1.33 [1.08, 1.63] for stooping, crouching or kneeling difficulty; 1.17 [0.91, 1.50] for lifting or carrying items weighting up to 10 pounds difficulty; 1.21 [1.01, 1.40] for standing up from armless chair difficulty; and 1.47 [1.05, 2.29] for ascending ten steps without pause difficulty. ConclusionsGlyphosate exposure may be a risk factor for decreased grip strength and increased physical functional limitations. More studies investigating the influence of this and other environmental pollutants on functional aging are needed.

Environmental exposure to glyphosate does not inhibit human acetylcholinesterase and butyrylcholinesterase.

Glyphosate has remained the leading herbicide on the global market to date, despite the continuous debate between consumers, scientific community, and regulatory agencies over its carcinogenicity, genotoxicity, environmental persistence, and the role in the development of neurodegenerative disorders. Chemically, glyphosate belongs to a large family of organophosphorus pesticides, which exert a neurotoxic effect by inhibiting acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), enzymes of the cholinergic system essential for maintaining neurotransmission. Although research shows that glyphosate is a weak cholinesterase inhibitor in fish and mammals compared to other OP compounds, no conclusive data exist concerning the inhibition of human AChE and BChE. In our study we analysed its inhibitory potency on human AChE and BChE, by establishing its IC50 and reversible inhibition in terms of dissociation inhibition constants. Glyphosate concentration of 40 mmol/L caused near total inhibition of enzyme activity (approx. 10 % activity remaining). Inhibition dissociation constants (K i) of glyphosate-AChE and -BChE complexes were 28.4±2.7 mmol/L and 19.3±1.8 mmol/L, respectively. In conclusion, glyphosate shows a slight binding preference for BChE but exhibits inhibition only in a high concentration range. Our results are in line with studies reporting that its neurotoxic effect is not primarily linked to the cholinergic system.

Application of confocal microscopy and flow cytometry to identify physiological responses of Prorocentrum micans to the herbicide glyphosate

The physiological response of the dinoflagellate P. micans to the effect of the herbicide glyphosate at a concentration of 25–200 μg L−1 was evaluated. It has been shown that P. micans is able to grow due to the consumption of dissolved organic phosphorus formed as a result of the mineralization of glyphosate by bacteria. The addition of glyphosate to the medium inhibits the photosynthetic activity of cells; there is a pronounced inhibition of the relative electron transfer rate along the electron transport chain and the maximum quantum efficiency of the use of light energy. Morphological and ultrastructural changes in P. micans cells were evaluated at sublethal (150 μg L−1) and lethal (200 μg L−1) glyphosate concentrations. It has been shown that at a herbicide concentration of 150 μg L−1, the first signs of apoptosis appear in most P. micans cells: a decrease in lateral light scattering, cytoplasmic retraction, partial destruction of cytoplasmic organelles, a change in the morphology of nuclei, mitochondria, a change in the potential of mitochondrial membranes, and a decrease in the autofluorescence of chlorophyll in cells. At a glyphosate concentration of 200 μg L−1, P. micans showed signs of a late stage of apoptosis: violation of the integrity of intracellular organelles and chromatin organization, fragmentation of nuclei, condensation of cytoplasm, disorganization of chloroplasts in the cells, and the release of cell contents beyond the cell membrane. The effectiveness of using flow cytometry and laser scanning confocal microscopy methods for identifying signs and stages of cell apoptosis when exposed to glyphosate is discussed.

Impact of glyphosate and glyphosate-based herbicides on phyllospheric Methylobacterium

Symbiotic Methylobacterium comprise a significant portion of the phyllospheric microbiome, and are known to benefit host plant growth, development, and confer tolerance to stress factors. The near ubiquitous use of the broad-spectrum herbicide, glyphosate, in farming operations globally has necessitated a more expansive evaluation of the impacts of the agent itself and formulations containing glyphosate on important components of the plant phyllosphere, including Methylobacterium.This study provides an investigation of the sensitivity of 18 strains of Methylobacterium to glyphosate and two commercially available glyphosate-based herbicides (GBH). Nearly all strains of Methylobacterium showed signs of sensitivity to the popular GBH formulations WeatherMax® and Transorb® in a modified Kirby Bauer experiment. However, exposure to pure forms of glyphosate did not show a significant effect on growth for any strain in both the Kirby Bauer test and in liquid broth, until polysorbate-20 (Tween20) was added as a surfactant. Artificially increasing membrane permeability through the introduction of polysorbate-20 caused a 78–84% reduction in bacterial cell biomass relative to controls containing glyphosate or high levels of surfactant only (0–9% and 6–37% reduction respectively). Concentrations of glyphosate as low as 0.05% w/v (500 µg/L) from both commercial formulations tested, inhibited the culturability of Methylobacterium on fresh nutrient-rich medium.To better understand the compatibility of important phyllospheric bacteria with commercial glyphosate-based herbicides, this study endeavours to characterize sensitivity in multiple strains of Methylobacterium, and explore possible mechanisms by which toxicity may be induced.

Glyphosate- and aminomethylphosphonic acid (AMPA)-induced mortality and residues in juvenile brown trout (Salmo trutta f. fario) exposed at different temperatures

BackgroundGlyphosate is a broad-spectrum, non-selective systemic herbicide with a commonly assumed low potential for accumulation in biota. Nevertheless, glyphosate has been shown to bioaccumulate in the tissues of several organisms. To understand the bioconcentration dynamics of glyphosate in fish, brown trout (Salmo trutta forma fario) of different age were exposed to different concentrations of glyphosate, the formulation Roundup® LB Plus, and the major transformation product aminomethylphosphonic acid (AMPA) for two, three, or four weeks at different temperatures in the laboratory. Mortality rates were determined, and tissue samples were collected at the end of the experiment to ascertain concentrations of glyphosate and AMPA residues by liquid chromatography coupled to mass spectrometry (LC–MS/MS).ResultsBrown trout mortality during exposure to glyphosate or AMPA was considerably higher at 15 °C than at 7 °C. Also, a significant increase in glyphosate concentrations in samples containing muscle, head, backbone, and caudal fin tissue with increasing exposure concentrations and temperatures was observed. Six-month-old fish contained more glyphosate per kg wet weight after exposure than ten-month-old fish. The bioconcentration factors (BCFs) for glyphosate and AMPA were much higher at 15 °C than at 7 °C, but in both cases decreased with higher glyphosate concentrations. The BCF for glyphosate formulated in Roundup® was higher than the one for the parent compound. Approximately 30–42% of the organ-absorbed glyphosate and AMPA remained in the tissues even when the fish were kept in clean water lacking the test substances for three weeks after termination of exposure.ConclusionOur study demonstrated that there is an interaction between glyphosate and ambient temperature in terms of toxicity. Further it was shown that increasing concentrations of glyphosate and AMPA in the surrounding media lead to significantly increased concentrations of these substances in brown trout tissues, although neither bioconcentration nor bioaccumulation of glyphosate in animal tissues is expected due to the high water solubility of this chemical. As a consequence, the uptake of glyphosate by humans through the consumption of contaminated edible fish is very likely.

Removal characteristics of high concentration glyphosate in bioretention cells

ABSTRACT Glyphosate, as one of the most widely used pesticides, has been found in rainwater runoff. A bioretention cell with two types of fillers was constructed to explore removal of glyphosate in runoff an transformation of glyphosate in the filler. The type of filler had a significant impact on adsorption and degradation of glyphosate in the bioretention cell. The glyphosate removal efficiencies of coal cinder modified loess (CLB) and zeolite modified loess (ZLB) were 33.13–99.7% and 55.04–99.7%, respectively. Conversion of glyphosate in the bioretention cell occurred mainly in the upper layer of the filler. When the concentration of glyphosate in the runoff was 0.25 or 0.5 mg/L, the concentration of glyphosate degradation products at the two outlets along the way was as much as 26 times higher than that at the lowest outlet. Rainfall events promoted the migration of glyphosate and its degradation products within the filler. Glyphosate and its degradation products in ZLB were mainly distributed at 15 and 25 cm deep in the filler layer, while the highest concentrations in CLB were at 5 and 35 cm. Discontinuous runoff into the bioretention cell leads to continuous leaching and adsorption of glyphosate in the bioretention cell until complete degradation occurs.

Developmental effects of zebrafish (Danio rerio) embryos after exposure to glyphosate and lead mixtures

Natural aquatic environments have a heterogeneous composition; therefore, simultaneous exposure to multiple contaminants is relevant and more realistic when assessing exposure and toxicity. This study examines the combinatorial effects of two compounds found ubiquitously in drinking water across the United States: glyphosate and lead acetate. Zebrafish (Danio rerio) embryos were used as a model for investigating developmental delays following controlled exposures. Six different environmentally relevant exposure concentrations of glyphosate, ranging from 0.001 to 10 ppm, and lead acetate, ranging from 0.5 to 4 ppm, were applied first as single exposures and then as co-exposures. The sublethal endpoints of hatching and coagulation were quantified to determine potencies. Results indicate that higher concentrations of the individual chemicals correlate with later hatching with correlation coefficients of 0.71 and 0.40 for glyphosate and lead acetate respectively, while the co-exposure at lower concentrations induced earlier hatching with a correlation coefficient 0.74. In addition, increased levels of coagulation and glutathione reductase activity were observed following co-exposure, as compared to the individual exposures, suggesting potential toxicological interactions. These results support the need for further work assessing the combined potencies of aquatic contaminants rather than individual exposures.

Zooplankton vulnerability to glyphosate exacerbated by global change

Anthropogenic activities generate a severe footprint at a global scale. Intensive agriculture is a global change driver that affects aquatic systems due to the discharge of pollutants. This situation can be modified or aggravated by other aspects, such as the disturbance history and other global change factors. Following our study line, it is necessary to evaluate how the disturbance history combined with temperature changes can affect the functioning of aquatic systems. The objectives of this study were divided into two phases. The objectives of phase 1 were to induce vulnerability in Daphnia magna populations through a disturbance history based on sublethal glyphosate concentration exposure under different temperature conditions (20 °C and 25 °C). In phase 2, vulnerability was assessed through the exposure to subsequent stressors (starvation, increased salinity and paracetamol) combined with changes in temperature. During the glyphosate exposure period in phase 1, differences were observed in the D. magna populations with respect to temperature, with lower abundance at 25 °C than at 20 °C. However, no differences were observed in abundance regarding glyphosate treatment. The results obtained in phase 2 with the new stressors combined with temperature changes in both directions, revealed stronger effects in vulnerable populations than in control populations. In addition, the temperature changes modulated the effects in the starvation and increased salinity tests. Agrochemical sublethal concentrations induce vulnerability in D. magna populations and inflicted temperature changes can act as a modulating factor for this vulnerability, showing the complexity in assessing the responses under the multiple scenarios associated with global change.

Phytotoxic and cytogenotoxic assessment of glyphosate on Lactuca sativa L.

The active ingredient glyphosate is the most commercialized herbicide on the world market due to its capability in eliminating weeds. However, it can harm the development of non-target organisms and threaten environmental quality. This study analyzed the effects of potentially toxic concentrations of glyphosate on germination, growth, cell cycle and genomic stability of Lactuca sativa L., and identified the most sensitive variables for assessing the toxicity of this herbicide to this biomonitor. Seeds of L. sativa were germinated in Petri dishes containing a sheet of filter paper moistened with 5 mL of a concentration of glyphosate (1.34, 3.35, 6.70, 10.05, 13.40 mg L-1). Controls consisted of distilled water (negative) and 3 mg L-1 CuSO4 (positive). Macroscopic and microscopic variables were analyzed. The germination of L. sativa was not affected by the concentrations of glyphosate. Root length and shoot height of the plants and the mitotic index decreased from the lowest concentration tested on. The chromosomal anomaly index and frequency of micronuclei increased by 3.2 and 22 times, respectively, with the presence of the lowest concentration of glyphosate compared to the negative control. The observed phytotoxic and cytogenotoxic effects demonstrate the negative influence that glyphosate has on the development of L. sativa. Root length and microscopic variables showed the highest sensitivity. This study warns of the possible harmful effects that glyphosate can have on non-target organisms and suggests greater control over the use of this herbicide to mitigate its environmental impact.

Effects of Low Concentration of Glyphosate-Based Herbicide on Genotoxic, Oxidative, Inflammatory, and Behavioral Meters in Danio rerio (Teleostei and Cyprinidae).

The glyphosate herbicide is a pesticide widely used in the world and can contaminate soil, air, and water. The objective of this work was to evaluate the toxicity of a glyphosate-based herbicide (GBH) in zebrafish (Danio rerio). Fish were exposed to different concentrations of GBH (0, 50, 250, and 500 µg/L) for 96 hours. Brain, liver, and blood were collected for biochemical and genotoxicity analyses, and behavioral tests were performed. The results showed that there was a reduction in the activity of the antioxidant enzymes of catalase (CAT) and glutathione-S-transferase (GST) in the liver at all concentrations and at the highest concentration in the brain. There was also a reduction in lipid peroxidation in the liver at all concentrations of glyphosate. There was an increase in micronuclei in the blood at the 500 µg/L concentration. However, the count of nuclear abnormalities showed no differences from the control. Interleukin-1beta (IL-1β) generation was inhibited at all concentrations in the liver and at the highest concentration in the brain. No significant differences were found in the behavioral test compared to the control. The results showed that acute exposure to GBH promoted an inflammatory event, which reduced the efficiency of antioxidants, thus producing a disturbance in tissues, mainly in the liver, causing immunosuppression and generating genotoxicity.

Exploring the interactions of glyphosate in soil: the sorption scenario upon soil depletion and effect on waterleaf (Talinum triangulare) growth.

The pesticide glyphosate has contributed immensely to the ease of farming and high yields. However, the ever-increasing environmental input of pesticides is of particular interest due to several unintended effects on non-target organisms. In soil, the sorption, transport, possible uptake, and effect on plant growth are still not well understood, and much so for the sub-Sahara. Sorption processes are contingent on the soil composition, characteristics, and ambient conditions, and these are becoming increasingly affected by climate change in a way that may alter pesticide fate. Hence, representative sub-Saharan whole soil (WS) treated to eliminate organic matter (OMR) and iron oxides (IOR) was employed to ascertain the contributions of these major constituents to glyphosate sorption processes, as well as ascertain the effect of glyphosate in soil on the growth of Talinum triangulare-waterleaf. Glyphosate sorption for all treatments was rapid with equilibrium at around 720 min. The sorption decreased as pH increased, and was concentration-dependent, gradually increasing with glyphosate concentration. The process was endothermic, and sorption data were better described by the fractal pseudo-second-order and Freundlich adsorption isotherm models, suggesting a complex interplay of interactive sorption forces. The IOR sample (with iron oxide depleted but organic matter intact) exhibited higher sorption than the OMR and WS, highlighting the contribution of organic matter in glyphosate sorption. Hysteresis was high for all samples and increased with temperature. Considering the unregulated usage of glyphosate in the sub-Sahara, the poor sorption, especially in treated soils, observed in this study suggests a high possibility of glyphosate leaching into the aquifer and poisoning of this water source, while the high hysteresis implied the bio-availability of glyphosate in surface soil for plant absorption, hence affecting growth; as confirmed in the waterleaf growth study where growth in the organic-matter/iron-oxide-depleted soils was substantially stunted. Hence, glyphosate affects waterleaf growth, especially in organic-matter/iron-oxide-depleted soils.

Effect of glyphosate contamination on surface charge change and nutrients of degraded Inceptisols ameliorated with sub-bituminous coal

The widespread use of glyphosate to eradicate weeds in agricultural areas has the potential for contamination and residues in the soil that must be carefully considered. This study aimed to elucidate the effect of glyphosate contamination on the chemical properties of an Inceptisol ameliorated with sub-bituminous coal. This study used a completely randomized design with three treatments and three replications, namely A = control (soil with no glyphosate and sub-bituminous coal), B = 5 kg soil + 100 mg glyphosate L-1, and C = 5 kg soil + 40 t sub-bituminous coal ha-1 + 100 mg glyphosate L-1. The results showed that glyphosate contamination significantly affected pH, electrical conductivity (EC), mineral and organic matter (OM) composition, cation exchange capacity (CEC), organic carbon (OC), total N, and available P of an Inceptisol ameliorated with sub-bituminous coal. The application of 40 t sub-bituminous coal ha-1 as an alternative ameliorant improved pH H2O by 0.30, EC by 0.05 dS m-1, OM by 1.03%, CEC by 18.08 cmol(+) kg-1, OC by 1.16%, total N by 0.20% and available P by 5.47 ppm of the soil compared to the control. The residual glyphosate concentration in the soil ameliorated with sub-bituminous coal was 0.04 mg kg-1 compared to the initial glyphosate concentration of 100 mg L-1. The correlation between glyphosate residue had no significant relationship with the chemical properties of an Inceptisol ameliorated with sub-bituminous coal.

Eficácia in vitro do benzoato de emamectina e do glifosato contra parasitos monogenéticos de Colossoma macropomum

ABSTRACT This study investigated the in vitro efficacy of emamectin benzoate and glyphosate against monogeneans from Colossoma macropomum and tolerance of this species to these therapeutic drugs. In vitro assays demonstrated that concentrations of emamectin benzoate (12.5, 16.6, 20.8 and 25.0g/L) and glyphosate (2,000; 3,000; 4,000 and 5,000mg/L) were 100% effective against Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri. The highest concentrations of emamectin benzoate (20.8 and 25.0g/L) were 100% effective after 30 minutes of exposure. For glyphosate, the highest concentrations were the most effective, and 4,000 and 5,000 mg/L immobilized 100% of parasites in 45 minutes and 30 minutes, respectively. Scanning electron microscopy revealed that the parasites exposed to 20.8 and 25.0g/L of emamectin benzoate and 5,000 mg/L of glyphosate presented integument covered with deeper wrinkles. Behavioral changes occurred in C. macropomum exposed to all concentrations of both drugs, were as mortality occurred following exposure to emamectin benzoate and glyphosate at 2.0,12,5 and 25.0g/L and 500, 1,000, 2,000, 3,000, 4,000 and 5,000mg/L, respectively. Low concentrations of emamectin benzoate and of glyphosate were tolerated by C. macropomum, but these concentrations may have not efficacy against infection of monogeneans.

Photocatalytic degradation of glyphosate using TiO2/Al2O3 using Box-Behnken Design

The TiO2/Al2O3 photocatalyst was produced through a hydrothermal process. The experiment was based on Box-Behnken design (BBD) considering three factors with three levels. A total of 17 experiments were designed and conducted to study the effect of variables such as TiO2/Al2O3 photocatalyst ratio (50:50 - 90:10), TiO2/Al2O3 photocatalyst amount (1.0 g – 40.0 g), and initial concentration of glyphosate (5.0 - 10.0 mg/L) on the percentage of degradation. Glyphosate degradation was conducted under UV light for three hours and monitored using a UV-Vis spectrophotometer (DR6000 HACH). Regression analysis was used to model the experimental results, and a quadratic model was established to study the effect of selected variables on the percentage of degradation. The optimal degradation percentage of 99.87% at the ratio of 50:50 TiO2 to Al2O3, the amount of 40.0 g photocatalyst TiO2/Al2O3 used, and the initial concentration of glyphosate 7.5 mg/L was obtained from the developed RSM model, and the optimized conditions were verified with experimental results. The degradation percentage was predicted using a second-order polynomial model, and the coefficient of determination (R2) were determined as 0.9133. Process variables optimized for percentage degradation were a good match for the BBD method. Finally, the prepared TiO2/Al2O3 photocatalyst was beneficial in degrading herbicides.

The Effect of Silica Nanoparticles Addition on Removal of Glyphosate Residue from Aqueous Solutions

Al-Tharwani, W.S., M.T. Mohammadali and I.M. Abd al-Ridha. 2024. The Effect of Silica Nanoparticles Addition on Removal of Glyphosate Residue from Aqueous Solutions. Arab Journal of Plant Protection, 42(2): 255-259. https://doi.org/10.22268/AJPP-001231 The aim of this study was to evaluate herbicide Tiller 48% SL (Glyphosate) residues in aqueous water by using silica nanoparticles as adsorption agent to remove glyphosate from aqueous solutions. Results obtained showed that when three concentrations of 10, 15 and 20 ml/L water were used, glyphosate concentration determined immediately after treatment was 3520, 5600 and 7955 mg/L, respectively. The concentration of the herbicide decreased with time and reached 1203 mg/L on the tenth day after treatment. No residues were detected by HPLC 21 days after treatment. The results of the study of the use of Nano-silica as an agent for the removal of glyphosate in aqueous solutions showed that the concentration 200 mg/L nano-silica achieved the highest rate of herbicide removal of 89.37%, outperforming the other two concentrations of 100 and 150 mg/L, which achieved 63.45 and 82.87% removal, respectively. Keywords: Glyphosate, residues, silica nanoparticles, adsorptio

Response Surface Method for the Optimization of Glyphosate Degrada-tion by Bacillus sp. Isolated from Soils Near Lake Maninjau

The study utilized a Box-Behnken experimental design to assess the impact of three parameters on the percentage of glyphosate biodegradation by a bacterium. The variables examined were incuba-tion period (measured in days), glyphosate concentration (measured in grams per liter), and pH, each assessed at three different levels. The quadratic model, which has squared terms, interaction products, linear terms, and an intercept, most accurately characterizes the connection between the variables and the response. The findings demonstrated that glyphosate concentration exerted the most pronounced impact on glyphosate degradation, with pH ranking second, as supported by substantial F-values and low p-values. The incubation period had no discernible effect. The ANOVA analysis validated the dependability of the model, as evidenced by an R² value of 0.9602 and an adjusted R² value of 0.9091. These values indicate that the model accounts for 90% of the variability observed in the response data. The contour and response surface plots demon-strated substantial interactions among the variables, specifically between pH and glyphosate con-centration and between the incubation period and glyphosate concentration. The model's anticipat-ed optimal conditions were experimentally tested, demonstrating no significant deviation from the projected values. The predicted maximum biodegradation of 90.097% closely matched the exper-imentally observed value of 92.505% (p&gt;0.05). The predicted combination to give the desired maximum response was at pH 6.81, glyphosate concentration of 0.692 g/L and an incubation period of 3.092 days. On the other hand, the predicted combination to give the desired maximum response is based on the requirement for the conditions where biodegradation is at the highest possible glyphosate concentration of 0.844 g/L and an incubation period of 3.112 days. A higher response of about 5.779% degradation was achieved through RSM. This study showcases the efficacy of the Box-Behnken design in optimizing biodegradation processes, offering a solid sta-tistical basis for further investigations on glyphosate degradation.