Comparison of the drinking water standard for pesticides of the Brazil with other countries

Low concentrations of complex mixtures of pesticides and metabolites are toxic to common Carp brain cells (Cyprinus carpio carpio)

Pesticide use increases annually, and Brazil is the world's largest consumer. However, unlike the European Union (EU), there is no established limit value for pesticide mixtures in drinking water, and therefore the concentration of pesticides can reach 3354 times the EU limit. Thus, determining the risk of exposure to pesticide mixtures and their main metabolites is challenging and requires the use of alternative methods. In the present study, the Common Carp Brain (CCB) cell line was used to evaluate the in vitro toxicity of relevant pesticide mixtures (glyphosate, 2,4-D, atrazine, and mancozeb) and their main metabolites after 72 h of exposure. The tested concentrations were based on the Acceptable Daily Intake (ADI) defined by Brazilian legislation. The results showed that cells exposed to lower concentrations of the pesticide mixtures and the pesticide + metabolite mixtures were affected by a decrease in cell confluence, resazurin metabolism, and wound healing capacity. The IBR index showed that lower concentrations had more severe effects, suggesting the absence of safe concentrations of these pesticide and metabolite mixtures for the CCB cell line within the tested concentration range. These findings raise concerns about the effects of exposure to these substances on animal and human health.

Effects of pasture intensification and sugarcane cultivation on non-target species: A realistic evaluation in pesticide-contaminated mesocosms

Conventional soil management in agricultural areas may expose non-target organisms living nearby to several types of contaminants. In this study, the effects of soil management in extensive pasture (EP), intensive pasture (IP), and sugarcane crops (C) were evaluated in a realistic-field-scale study. Thirteen aquatic mesocosms embedded in EP, IP, and C treatments were monitored over 392 days. The recommended management for each of the areas was simulated, such as tillage, fertilizer, pesticides (i.e. 2,4-D, fipronil) and vinasse application, and cattle pasture. To access the potential toxic effects that the different steps of soil management in these areas may cause, the cladoceran Ceriophania silvestrii was used as aquatic bioindicator, the dicot Eruca sativa as phytotoxicity bioindicator in water, and the dipteran Chironomus sancticaroli as sediment bioindicator. Generalized linear mixed models were used to identify differences between the treatments. Low concentrations of 2,4-D (<97 μg L-1) and fipronil (<0.21 μg L-1) in water were able to alter fecundity, female survival, and the intrinsic rate of population increase of C. silvestrii in IP and C treatments. Similarly, the dicot E. sativa had germination, shoot and root growth affected mainly by 2,4-D concentrations in the water. For C. sancticarolli, larval development was affected by the presence of fipronil (<402.6 ng g-1). The acidic pH (below 5) reduced the fecundity and female survival of C. silvestrii and affected the germination and growth of E. sativa. Fecundity and female survival of C. silvestrii decrease in the presence of phosphorus-containing elements. The outcomes of this study may improve our understanding of the consequences of exposure of freshwater biota to complex stressors in an environment that is rapidly and constantly changing.

Adsorption of diazinon from aqueous solution using metal organic framework and functionalized graphene: Comparison of BBD, ANN models

In the present study, metal organic frameworks (MOFs) and aminated graphitic carbonaceous structure (ACS-RGO) through chemical synthesis prepared by a simple precipitation method and used for diazinon removal. Several techniques such as XRD , FESEM and FTIR were applied for identification of MOF-5 and ACS-RGO. Also, response surface methodology (RSM) was employed in this work to look at the effectiveness of diazinon adsorption. To forecast pesticide removal, we applied artificial neural network (ANN) and Box-Behnken Design (BBD) models. For the ANN model, a sensitivity analysis was also performed. The effect of independent variables like solution pH, various concentrations of diazinon, MOFs and ACS-RGO adsorbent dose and contact time were assessed to find out the optimum conditions. Based on the model prediction, the optimal condition for adsorption ACS-RGO and MOF-5 were determined to be pH 6.6 and 6.6, adsorbent dose of 0.59 and 0.906 g/L, and mixing time of 52.15 and 36.96 min respectively. These conditions resulted in 96.69% and 80.62% diazinon removal using ACS-RGO and MOF-5, respectively. Isotherm studies proved the adsorption of ACS-RGO and MOF-5 following the Langmuir isotherm model for diazinon removal. Diazinon removal followed by the pseudo-second and Pseudo-first order kinetics model provides a better fit for analyzing the kinetic data associated with pesticide adsorption for ACS-RGO and MOF-5, respectively. Based on the obtained results, the predicted values for the efficiency of diazinon removal with the ANN and BBD were similar (R2=0.98). Therefore, two models were able to predict diazinon removal by ACS-RGO and MOF-5.

Are the issues involving acephate already resolved? A scientometric review

Acephate is a pesticide classified as moderately toxic, and its metabolite methamidophos is highly toxic for mammals and birds; even so, it is one of the most used insecticides in pest control for agricultural and domestic use. Acephate toxicity affects both target and non-target organisms and causes serious damage to the environment. There are several studies on different perspectives of acephate, such as monitoring, toxicity, and modeling. In this sense, this research aims to identify the structure of intellectual production on acephate and analyze the gaps and trends of scientific production on acephate through a scientometric analysis. The data was obtained from the Web of Science database, and after the refinement, 1.085 documents were used. A temporal pattern of the main research objectives is displayed. Most selected studies evaluated acephate efficiency, followed by toxicity and residue detection methods. The USA, China, India, Brazil, and Japan had the highest number of publications on acephate. The keywords most utilized were pesticides, toxicity, insecticide resistance, and residue. Research involving acephate requires greater attention from areas such as ecotoxicology, biochemistry, genetics, and biotechnology. There needed to be more discussions on chronic toxicity, genotoxicity, and cytotoxicity. Moreover, few studies about metabolic and biochemical pathways and genes related to acephate action and biodegradation were scarce.