Application of Water Model for the Evaluation of Pesticide Exposure

Pesticide is used to protect the crops, but also become a cause of polluting the environment.Perform a risk assessment using physical and chemical properties, environmental fate and toxicity data inorder to determine the pesticide registration. The aquatic model estimates pesticide concentrations in waterbodies that result from pesticide applications to rice paddies and apple orchard. The used models are thePRZM, EXAMS and AGRO shell (PA5), Rice Water Quality Model (RICEWQ) and Screening ConcentrationIn GROund Water (SCI-GROW). The residual concentration of water body was estimated using meteorologicaldata, crop calendar and soil series of Korea. The chosen pesticides were butachlor, carbofuran, iprobenfos andtebuconazole. It has shown the potential that the RICEWQ is possible to predict residue level in water ofbutachlor and iprobenfos, because the maximum value in water monitoring data is lower than the peakconcentration of the model, and the minimum value is lower than the average annual concentration of themodel. But RICEWQ was insufficient to predict exposure concentrations in ground water. The estimatedexposure concentrations of carbofuran in ground water is very higher than in surface water because of its lowsoil adsorption coefficient. Although tebuconazole were not detected in the water monitoring that means verylow concentration, it is possible that the PA5 can be used to predict residue level in water.Key words rice paddies, water model, RICEWQ, SCI-GROW, PA5