Inhalation bioaccessibility of inhaled triazole fungicides and health risk assessment during spraying.

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 an in vitro method for the inhalation bioaccessibility (IBA) measurement of triazole fungicides and to incorporate this into inhalation exposure assessment during pesticide spraying.

Results: The IBA of triazole fungicides increased logarithmically with extraction duration, plateauing after 6 h. The frequency of agitation displayed a similar pattern, whereas 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 optimized 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 -2.1 × 10  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 were calculated to be within an acceptable level.

Conclusion: This in vitro method supplements bioaccessibility evaluation based on pesticide inhalation exposure, along with the risk to human health. © 2023 Society of Chemical Industry.