Degradation patterns and risks quantification of chlorfluazuron, chlorfenapyr and metabolite in chives by multi-model...

Elucidating the degradation fate and risk characteristics of chlorfluazuron, chlorfenapyr, and its metabolite in chives in both open-field and greenhouse cultivations is crucial for safeguarding the ecosystem and humans from their hazardous effects. This study shows that the dissipation pattern and concentration variations of these pesticides are governed by multiple factors, including cultivation patterns and climatic conditions. A biexponential model revealed that the half-lives of chlorfluazuron and chlorfenapyr were 5.4-11.8 d and 3.3-11.6 d in chives, respectively, as indicated by lower akaike information criterion values and the residual mass closer to zero. Additionally, tralopyril was detected at concentrations up to 0.02 mg/kg after chlorfenapyr application. A novel risk assessment framework was developed by integrating deterministic modeling with probabilistic Monte Carlo simulation. The deterministic model showed that the chronic dietary risks of chlorfluazuron and chlorfenapyr in chives were 4.731%-12.969% and 0.523%-1.434%, respectively. Children aged 2-6 years were identified as the most significantly exposed group, with risk levels approximately 1.4-1.8 times higher than other groups. Furthermore, rural residents exhibited markedly greater exposure risk than urban counterparts. Notably, chlorfluazuron accounted for 90.04% of the cumulative risk, thereby being prioritized in risk management strategies. Although the exposure risks were acceptable, the potential health hazards of chlorfluazuron to vulnerable groups should be taken into account, given its widespread presence and high contribution to combined risks.