LAUSR

BACKGROUND Ambient air pollution caused by pesticide drift has received great attention. To accurately evaluate the health risk of inhaled pesticides, bioaccessibility should be considered. However, methods to reliably assess pesticide residues remain limited, hindering the precise estimation of exposure assessment. We aimed to optimize in vitro method for inhalation bioaccessibility (IBA) measurement of triazole fungicides and to incorporate it into inhalation exposure assessment during pesticide spraying. RESULTS IBA of triazole fungicides increased logarithmically with extraction duration, plateauing after 6 hours. The frequency of agitation displayed a similar pattern, while the ratio of solid to liquid between 1/1500 and 1/250 was considerably negatively associated. The predicted values (35.9-53.5%) for IBA based on optimised methodological parameters determined using a response surface methodology showed an acceptable deviation from experimental values (30.7-50.8%), suggesting feasibility for in vitro IBA measurement. Incorporating IBA into calculations of inhalation exposure amount (IE) yielded a value of 8.5×10-7 -2.1×10-5 mg/kg/day, a 50-68% reduction compared to IE based on total amount. Additionally, the safety exposure threshold was determined for triazole fungicides using benchmark dose modelling of data from lung A549 cell proliferation toxicity assays, and in this context, margin of exposure (MOE) values was calculated to be within an acceptable level. CONCLUSION The findings supplement the bioaccessibility evaluation based on pesticide inhalation exposure, along with the risk to human health.