Abstract
A model with which to estimate long-term average atmospheric concentrations of chemicals was developed. The model validation was conducted for trichloroethylene and tetrachloroethylene concentrations in atmosphere by comparing calculated values and observed values from a monitoring survey conducted over several weeks in summer and winter in the Kanto region. A good agreement with the measured values was obtained for the monthly average concentration of trichloroethylene, excluding two sites in the winter measurements where the monitored values were extremely high. For tetrachloroethylene, the calculated values greatly overestimated the monitored values at urban sites. The use of emission data with better accuracy will be able to improve the model performance, because the extremely high calculated value was mainly influenced by the methodology used to estimate the gridded source inventory. The model is capable of estimating the long-term (such as monthly) average concentration distribution of chemicals in a wide flat area such as the Kanto plain.
