Behavior of Atmospheric PCDDs and PCDFs in Osaka

The data of atmospheric PCDDs and PCDFs, determined by HRGC/HRMS in 1996 and also by HRGC/LRMS in 1986-1994 in Osaka, were analyzed to clarify compositions of their congeners in summer and winter and effects of wind and emission sources on the concentrations. In 1996, penta- and hexachlorinated PCDDs and PCDFs were found to be major, and to contribute mainly to the respective total TEQs. The concentrations of PCDDs and PCDFs in 1986-1996 were relatively high at 1.5-2.0m/s of averaged wind speed. In some urban areas, the data showed that PCDDs and PCDFs were distributed in higher concentrations down the wind of urban garbage incinerators.