Modification of sedimentation and bioaccumulation behavior as an efficient strategy to modulate the toxicity of pyraclostrobin to zebrafish (Danio rerio)

The behavior of pesticide particles or droplets might significantly influence their environmental risks. However, studies on the risk of different pesticide formulations in aqueous environments have rarely been reported. In this study, we prepared three types of pyraclostrobin formulations to evaluate their behavior in the aqueous envi-ronment and toxicological risks to zebrafish. The results showed that pyraclostrobin emulsifiable concentrate (EC) sank faster in water with increasing hydrophilicity and density of the solvent. The particles also sank faster with increasing particle size and particle density for suspension concentrate (SC) and microcapsules (MCs). Diverse behavior in water results in different temporal and spatial distributions of the active ingredient. EC-EGDA, SC-5 mu m, CS-Large and EC-MO sink or float over time, therefore reducing the effective dose suspended in water. Lower toxicological risks of the pesticides were also observed by reducing the enrichment of pyr-aclostrobin in zebrafish. In addition to the direct toxicity of the active ingredient, the type of pesticide formu-lations and their specific compositions might also influence the integrated toxicity. The environmental behavior of pesticide formulations should also be considered for their systematic assessment of environmental risks to ensure the scientific application of pesticides in different scenarios.