Modeling the impact of pesticide drift deposition on off-field non-target receptors

Abstract

Pesticide application can result in residue drift deposition in off-field areas, which can be harmful to non-target organisms inhabiting adjacent off-field environments. In order to comprehend the impact of pesticide drift deposition on off-field non-target organisms, an integrated modeling approach was incorporated into the life cycle analysis perspective for the assessment of their exposure to pesticide residues and the characterization of their human toxicity and ecotoxicity potentials. The modeling assumption comprises four modeling scenarios: children & cattle & sensitive crops (tomatoes) based on exposure assessment, and the continent-scale human health toxicity & ecotoxicity under a life cycle analysis perspective. The simulation results for the nearby off-field exposure scenario revealed that pesticide dissipation kinetics in environments and drift deposition type were two important factors influencing non-target organisms' exposure to pesticide residues deposited in off-field environments. The continental scenario simulated via USEtox revealed that considering off-field drift deposition resulted in lower simulated human toxicity potentials of pesticides when compared to simulation results that did not consider drift deposition, given that pesticide residues remaining within the treated field contributed the most to overall human exposure. Taking drift deposition into account, on the other hand, could result in higher or lower simulated ecotoxicity potentials of pesticides than not taking drift deposition in off-field areas into account, depending on the physicochemical properties of pesticides. The proposed modeling approach, which is adaptable to drift deposition types and chemical species, can aid in investigating the off-field impacts of pesticide residues. Future research will incorporate spatiotemporal factors to characterize region-specific drift deposition functions and pesticide fate in off-field environments to conduct site-specific impact assessments.