Exposure to high-performance benzotriazole ultraviolet stabilizers: Advance in toxicological effects, environmental behaviors and remediation mechanism using in-silica methods

Comparative evaluation of soil accumulation of light stabilizers from biodegradable mulching films versus conventional polyethylene ones

Light stabilizers are commonly used as additives in mulching films and have environmental persistence, bioaccumulation and ecotoxicity. However, their occurrence and distribution in mulching films and accumulation in mulched soils are seldom reported. This study firstly presents a comprehensive screening of 19 light stabilizers in 65 mulching films and 30 farmland soils collected in China, of which five and eight light stabilizers were 100% detected, respectively. The light stabilizer concentration in biodegradable mulching films was significantly higher than that in polyethylene ones, with median concentrations of 1.75 × 106 μg/kg and 4.86 × 103 μg/kg, respectively. Furthermore, a positive correlation was observed between the light stabilizer concentration in mulching films and in soils. This indicates that mulching films play a critical role in the accumulation of light stabilizers in farmland soils, and biodegradable mulching films significantly increase benzotriazole light stabilizers in soils. Although the light stabilizer concentration in farmland soil is relatively low, the sustainable quantities of mulching film input and the long-term accumulation will still pose a threat to the ecological environment and organism health. Consequently, our work reveals the occurrence and environmental risk of light stabilizers in mulching films and farmland soils and brings attention to light stabilizers in the soil environment.

Amide herbicides: Analysis of their environmental fate, combined plant-microorganism soil remediation scheme, and risk prevention and control strategies for sensitive populations

In this study, we predicted the environmental fate of amide herbicides (AHs) using the EQC (EQuilibrium Criterion) model. We found that the soil phase is the main reservoir of AHs in the environment. Second, a toxicokinetic prediction indicated that butachlor have a low human health risk, while the alachlor, acetochlor, metolachlor, napropamide, and propanil are all uncertain. To address the environmental and human-health-related threats posed by AHs, 27 new proteins/enzymes that easily absorb, degrade, and mineralize AHs were designed. Compared with the target protein/enzyme, the comprehensive evaluation value of the new proteins/enzymes increased significantly: the absorption protein increased by 20.29-113.49%; the degradation enzyme increased by 151.26-425.22%; and the mineralization enzyme increased by 23.70-52.16%. Further experiments revealed that the remediating effect of 13 new proteins/enzymes could be significantly enhanced to facilitate their applicability under real environmental conditions. The hydrophobic interactions, van der Waals forces, and polar solvation are the key factors influencing plant-microorganism remediation. Finally, the simulations revealed that appropriate consumption of kiwifruit or simultaneous consumption of ginseng, carrot, and spinach, and avoiding the simultaneous consumption of maize and carrot/spinach are the most effective means reduce the risk of exhibiting AH-linked toxicity.

Triazine Herbicides Risk Management Strategies on Environmental and Human Health Aspects Using In-Silico Methods

As an effective herbicide, 1, 3, 5-Triazine herbicides (S-THs) are used widely in the pesticide market. However, due to their chemical properties, S-THs severely threaten the environment and human health (e.g., human lung cytotoxicity). In this study, molecular docking, Analytic Hierarchy Process—Technique for Order Preference by Similarity to the Ideal Solution (AHP-TOPSIS), and a three-dimensional quantitative structure-active relationship (3D-QSAR) model were used to design S-TH substitutes with high herbicidal functionality, high microbial degradability, and low human lung cytotoxicity. We discovered a substitute, Derivative-5, with excellent overall performance. Furthermore, Taguchi orthogonal experiments, full factorial design of experiments, and the molecular dynamics method were used to identify three chemicals (namely, the coexistence of aspartic acid, alanine, and glycine) that could promote the degradation of S-THs in maize cropping fields. Finally, density functional theory (DFT), Estimation Programs Interface (EPI), pharmacokinetic, and toxicokinetic methods were used to further verify the high microbial degradability, favorable aquatic environment, and human health friendliness of Derivative 5. This study provided a new direction for further optimizations of novel pesticide chemicals.