Improving pesticide fate models for a simple household food processing: considering multiple crop units.

To understand the fate of pesticides in crops during household cooking processes and human health risks associated with the ingestion of pesticide-contaminated crops, we propose unit-variability-enhanced models, which are capable of evaluating the removal efficiency of pesticides in multiple crop units by soaking in water. The approach integrates the lognormal production model to reveal the modeling mechanics of internal contamination among two crop units in one soaking bowl. The simulated results for 197 pesticides indicate that pesticides with larger unit-to-unit variability factors (VF) at the residue levels and diffusivity rates in water (D W ) are more likely to cause internal contamination. Although internal contamination of pesticide residues between two crop units may occur, we find that the overall removal factor ([Formula: see text]) for two crop units is independent of the ratio of initial residue levels between the two crop units. Based on this discovery, we propose the unit-variability-based (UVB) rule to generalize the [Formula: see text] for an n-crop-unit system, where n crop units soak simultaneously in one container. In addition, we demonstrate that under the same consumable and recycling resources, the soaking of two crop units together in one container can yield a maximum mass removal of pesticides if the two units are randomly sampled. Although other factors, such as temperature and the nature of solutions in the cooking process, should be considered in future studies, our models suggest that this soaking method can be conveniently realized in households to reduce negative health effects.