Development of a simulation model "InPest" for prediction of indoor behaviors of house-hold insecticides

A computer software (to be registered as InPest) was developed in order to make a risk assessment of indoor-use insecticides to both applicators and i ndoor occupants in various applications including space spraying, electric vaporizing, broadcast spraying and residual spraying. The movement of an in secticide in a sprayed room was described as precisely as possible by utili zing various physicochemical equations, which were incorporated in the Fuga city model (Level IV). When insecticide information regarding molecular wei ght, vapor pressure, water solubility and octanol/water partition coefficie nt is available, InPest is able to simulate the time-dependent concentratio ns of the insecticide in the air and residual amounts on floor, wall and ce iling compartments under various conditions. Simulation data indicate that the predicted behavior of the insecticide fully agrees with the measured on e. Based on the predicted concentrations, the levels of exposure to applica tors and room occupants via inhalation, dermal or oral intake can be comput ed and compared with the mammalian toxicological data. Thus, InPest is a po werful tool for evaluating the safety of indoor-use insecticides with regar d to human health.