Enantioselective Behaviors of Chiral Fungicide Penthiopyrad in Five Kinds of Crops and Whole-Age Dietary Risk Assessments.

Abstract

Penthiopyrad is a widely used succinic dehydrogenase inhibitor fungicide with two enantiomers, while the data on its enantioselective behaviors in crops are limited. The enantioselective dissipation may directly or indirectly expose people to the preferentially residual enantiomer, which may affect the dietary risks of chiral penthiopyrad. In this study, the enantioselective behaviors of chiral penthiopyrad in five kinds of crops and whole-age dietary risk assessments were conducted. The dissipation half-lives of penthiopyrad enantiomers were in the range of 0.48-13.7 days. S-(+)-Penthiopyrad was preferentially dissipated in soybean plants, soybean, peanut kernel, peanut shell, celery, tomato, and soil, which was opposite in cabbage. The opposite enantioselective residue might expose people to different enantiomer, which bring more complex risks. On the 35th day (the harvest time), the residue concentrations of penthiopyrad were all lower than MRLs except celery. For acute dietary intake risks, the children aged 2-7 suffered the highest risks, especially for cabbage (RQa, 138%) and celery (RQa, 140%), which were unacceptable. For other people, the acute dietary intake risks of rac-penthiopyrad in cabbage and celery were also very high and in the range of 88.6-94.8%, which should raise concern. The chronic dietary intake risks of rac-penthiopyrad in the all crops for groups of Chinese population with different ages and genders were acceptable (HQ, 0.0006-29.1%), and the risks were the highest in celery, especially for children aged 2-7. This study could provide data support for the environmental behaviors and risk assessments of penthiopyrad at the enantiomeric level.