Investigation of the dissipation behaviour and exposure of flonicamid and imidacloprid in open field green beans under dry climatic conditions

Abstract

ABSTRACT Flonicamid and imidacloprid are insecticides that are commonly used for the protection of many annual open field crops, such as beans, against insects. Residues of these insecticides in the consumable product above the acceptable limits can cause health concerns or trade barriers; thus, the dissipation behaviour and the consumer risk assessment of flonicamid and imidacloprid residues in open field green beans were investigated. The initial concentrations were found to be 0.44 and 0.99 mg kg−1. The decline of residues followed in both cases the first-order kinetics model with half-lives of 2.3 (r2 0.912) and 2.1 (r2 0.977) days, for flonicamid and imidacloprid, respectively, while degraded almost completely after 14 days if applied according to the authorised patterns. The dietary risk assessment performed using the hazard quotient (RQ) and the EFSA PRIMo model showed no concern to consumer health with exposure values <2% of the acceptable daily intake (ADI) and <22% of the acute reference dose (ARfD) of each compound. In conclusion, the investigation of the dissipation behaviour of these compounds in green bean provides useful information to ensure safe pre-harvest intervals, acceptable dietary exposure and compliance with good agricultural practices and maximum residue levels.