DETERMINING OFF-SITE CONCENTRATIONS OF VOLATILE PESTICIDES USING THE TRAJECTORY-SIMULATION MODEL

An environmental transport model is described and illustrated that will enable the prediction of the mass and/or concentration of volatile pesticides at any depth in the soil profile and at any height in the atmosphere relatively far distanced downwind from agricultural fields. The theoretical profile shape model is used to determine transport in the atmosphere and is coupled to the behavior assessment model (BAM) to describe transport in soils. The model outputs include the soil-water concentrations, the surface volatilization rate, the concentration of pesticides in the atmosphere above the field, and the atmospheric concentration at specified distances downwind from the field. The results from this approach can be used in exposure assessment studies to determine the risk for individuals living near agricultural fields.