A Modeling Approach for Assessing Ecological Risks of Neonicotinoid Insecticides from Emission to Nontarget Organisms: A Case Study of Cotton Plant

The use of neonicotinoid insecticides in agriculture has posed threats to ecological systems, and there is a need to assess the ecological risks of neonicotinoids from emission to non-target organisms. In this study, we introduced a modeling approach to assess ecological risks of neonicotinoids using honeybee and earthworm as model organisms, for which the simulation was flexible with different environmental conditions. Using the cotton plant as an example, the simulation results demonstrated that under current recommended application rates, the use of common neonicotinoid insecticides posed no threat to earthworms, with the simulated risk quotients (RQs) much lower than 1. However, the simulation for some neonicotinoid insecticides (e.g., acetamiprid) indicated that using these insecticides on cotton plants could threaten honeybees, with simulated RQs higher than 1. The variability analysis marked that in high-latitude regions, the unacceptable risk to honeybees posed by insecticide application can be further elevated, due to cold, wet weather that results in relatively high insecticide levels in pollen and nectar. The model evaluation showed large overlaps of simulated risk intervals between the proposed and existing (BeeREX) models. As the proposed and existing models have different simulation mechanisms, we recommend that these two models can be used together to complement each other in future studies.This article is protected by copyright. All rights reserved. Environ Toxicol Chem 2023;00:0–0. © 2023 SETAC.