Comparison of Translocation, Distribution, Metabolism, and the Health Risk of Cyetpyrafen in Strawberry-Soil Systems...

Selection of the appropriate application method is critical for ensuring pesticide efficacy and food/environment safety. This study systematically compared the fate and health risks of cyetpyrafen in strawberry-soil systems under foliar spray and root irrigation. Foliar spray resulted in a limited downward translocation of cyetpyrafen with translocation factors (TF_root/leaf) of 0.002-0.006. In contrast, root irrigation led to its preferential accumulation in roots with root concentration factors up to 3.11 and limited upward translocation (TF_leaf/root: 0.01-0.13). Photoisomerization to E-cyetpyrafen (18.9-32.5%) was the dominant transformation pathway in strawberry plants under foliar spray, whereas cyetpyrafen was mainly hydrolyzed to M-309 (7.7-22.5%) in roots under root irrigation. Although its dietary risks for humans were acceptable (the maximum risk quotient: 7.29 × 10^-7) for both methods, M-309 in roots (up to 497.8 μg kg^-1) and soil (45.0 μg kg^-1) under root irrigation posed potential risks to nontarget organisms.