Neonicotinoid Residues in Fruits and Vegetables: An Integrated Dietary Exposure Assessment Approach

Neonicotinoids have become the most widely used insecticides in the world since introduced in the mid 1990s, yet the extent of human exposure and health impacts is not fully understood. In this study, the residues were analyzed of seven neonicotinoids in fruit and vegetable samples collected from two cross-sectional studies: the U.S. Congressional Cafeteria study (USCC) and the Hangzhou China (HZC) study. We then employed a relative potency factor method to integrate all neonicotinoids in each food sample using the respective reference dose values as the basis for summation. The findings were compared with data published by the U.S. Department of Agriculture Pesticide Data Program (USDA/PDP). Imidacloprid and thiamethoxam were the most commonly detected neonicotinoids in fruits and vegetables with 66 and 51% detection in the HZC study and 52 and 53% detection in the USCC study, respectively. The overall frequency of detection for neonicotinoids in the USDA/PDP samples was much lower than those reported here for the USCC or HZC studies, with imidacloprid being the most frequently detected neonicotinoid at 7.3%. The high frequencies of neonicotinoid detection in fruits and vegetables in the USCC and HZC studies give us a snapshot of the ubiquity of neonicotinoid use in global agriculture and make it clear that neonicotinoids have become part of the dietary staple, with possible health implications for individuals.