Food Sustainability

Project Summary

Potential negative impacts of pesticides during and after applications on both environment and human health have always been a focus for evaluating current agricultural practice. These overall impacts can be evaluated based on the fate processes and the ultimate residues of the pesticides among different media, which includes air, water, soil, sediment and organism. However, it’s often hard to describe these processes comprehensively and efficiently, since the fate of the pesticides depend not only on the physicochemical properties of these substances, but also on the specific application methods, crop types and environmental conditions. As a result, for a certain pesticide, the dynamic residue concentrations in each media may vary greatly depending on different crop-environment combinations (planting patterns). Hence, pattern-specific assessments are necessary to avoid common inadequacies like insufficient evaluation in the existing approaches.To address this problem, a dynamic crop-based model, dynamiCROP, has been developed to first simulate the dynamic distribution of the pesticides during a crop season among multiple environmental media, and then to evaluate the human health impacts due to direct ingestion exposure of the cultivated crops. Along with dynamiCROP, a generic linear-regression model based on pesticide properties and crop types has also been proposed to provide the most critical parameter, pesticide half-lives in plants, that is necessary in dynamiCROP.

The current goal of the project is to utilize dynamiCROP as a framework to build/modify a model that is specific suitable for two typical and major Chinese Planting Patterns (Southern Paddy Rice and Heavily-Dosed Greenhouse Tomato), in order to provide critical information for a comprehensive assessment system for Chinese pesticide control in the future. Multimedia samples (soil, plant, water, and air) collected from the real agricultural sites in Changsha and Shouguang are being analyzed with LC-MS/MS for pesticide residues to build up and/or validate the dynamic processes in the model. To further judge the effects of pesticide application on the ecosystem, species sensitivity distribution (SSD) is selected as the tool to provide a comprehensive view for pesticide control of these two patterns.