Comparison of observed and estimated concentrations of volatile organic compounds using a Gaussian dispersion model in the vicinity of factories: an estimation approach to determine annual average concentrations and human health risks.

The concentrations of toluene and dichloromethane in the vicinity of factories that emitted a large amount of toluene or dichloromethane into the atmosphere were determined for the comparison of observed and estimated concentrations using a Gaussian dispersion model (METI-LIS model). Greater concentrations of toluene and dichloromethane than the guideline value described in the Air Quality Guidelines for Europe, second edition, were measured in the vicinity of factories (270 and 470 micro g/m(3) for toluene and 510 and 660 micro g/m(3) for dichloromethane). Toluene and dichloromethane may have some adverse health effects on the local population in the vicinity of the emission source. Although the estimated concentrations in the vicinity of the emission source by the METI-LIS model involved a large margin of error, the proposed correction approach with only one weekly measurement reduced the estimation error of annual average concentrations. The proposed method could be useful for the management of ambient environment of emission source, due to no difficulty in modifying the input parameters of METI-LIS that required highly specialized knowledge.