Enantiomer-Specific Study of Fenpropathrin in Soil-Earthworm Microcosms: Enantioselective Bioactivity, Bioaccumulation, and Toxicity.

In this study, the enantiomer-specific bioactivity, bioaccumulation, and toxicity of fenpropathrin (FEN) enantiomers were investigated in soil-earthworm microcosms. The bioactivity order was -FEN > -FEN > -FEN for and . Moreover, -FEN was 12.0 and 32.2 times more toxic than -FEN and -FEN to earthworms, respectively. -FEN degraded faster than -FEN with the enrichment of -FEN in the soil environment. Furthermore, the peak-shaped accumulation curves for FEN enantiomers were observed, and -FEN was preferentially bioaccumulated by earthworms. As compared to -FEN, -FEN induced greater changes in the activities of detoxification enzymes, antioxidant enzymes, and malondialdehyde content, which suggested that earthworms exhibited enantioselective defense responses to -FEN and -FEN. Integrated biomarker response results indicated that -FEN exhibited higher toxic effects on earthworms than -FEN. Finally, molecular simulation revealed that the greater interaction forces between -FEN and sodium channel protein could be the primary reason for the enantioselective bioactivity and toxicity of FEN enantiomers. This study comprehensively highlights the enantiomer-specific bioactivity, bioaccumulation, toxicity, and mechanism of FEN in soil-earthworm microcosms at the enantiomer level. Our findings will contribute to a better risk assessment of FEN in the soil ecosystem.