20032006年度の湿性沈着調査が示す越境大気汚染～ 全環研酸性雨全国調査結果より～

摘要

We analyzed trans-boundary transport of air pollutants from Asian continent to Japan focusing on winter season data which wereobtained with the Acid Deposition Survey conchmted by the Japan Environmental Laboratoires Association The continuons validated dataobtained from 39 sites during the four fiscal years (April 2003 - March 2007) were used. High concentrations and large depositions ofnss-SO42-, NO3-, NH4+ and Fr- ions were observed at JS (facing the Japan Sea) and WJ(Westem part of Japan) area in winter. The temporalchange amounts and rates of nss-SO42- deposition were also large at WJ and near-WJ sites. The depositions of NH4+, Fle.(= + 2NR4+) andEN (= NO3 + NH4+) hacl been increased year by year in the same area. These results suggested that the influence of trans-boundary transportof air pollutants over East Asia had been increased recently in the western part of Japan, and it is necessary to monitor trans-boundary transportof acidic substances as well as ammonia which contnbute soif acidification and excess nitmgen deposition.