Abstract
To evaluate the effect of trans-boundary and regional air pollution regarding precipitation, we collected precipitation from April 2000 through March 2001 in Yasaka, which has long-range transported air pollution, and Yahata which has regional air pollution from southern Kyoto prefecture and the Osaka plain. From the concentrations of water soluble ionic components, metal components, the ratio of metal concentrations and the lead isotope ratio, we evaluated the effect of anthropogenic pollutants and soil elements to chemical constituents in precipitation, based on the backward trajectory analysis. The ion balance of anion and cation was good in both Yasaka and Yahata; however, the total ion equivalent concentrations were higher in Yasaka than in Yahata. The effect of sea salt was more prominent in Yasaka than in Yahata which is located inland. As for metals of anthropogenic origin, the concentration levels and concentration variations were quite different in both sampling sites. From the analysis conducted of Pb/Zn, Sr/Mn, Pb/Cd and V/Mn in the precipitation, it was found that the ratios increased for long-range transported air pollution. In Yahata, a relatively similar metal concentration ratio was observed between aerosol in the urban area and in the precipitation. A high 207 Pb/206 Pb ratio was observed when the air mass travelled over central China and the Korean peninsula; on the other hand, a low 207 Pb/206Pb ratio was observed in Yahata regarding regional air pollution. The validity of the metal concentration ratios, as well as the lead isotope ratio, for the index of long-range transported and regional air pollution were clarified.
