カゴシマシ ノ タイキ オセン チョウサ ( ダイ5ホウ ) : ヘイセイ3ネンド チョウサ ホウコク

Air pollution in Kagoshima City from Aprill 1991 to March 1992 was investigated with particular emphasis on the falling dust (volcanic ashfall) from Mt. Sakurajima. The falling dust was collected monthly together with rain water at eight locations in Kagoshima city. After the sample had been filtered, the residue was dried and weighed, and the filtrate was analyzed for SO_4^{2-}, Cl^-, and water-soluble matter as well as for pH. The average monthly falling dust at eight locations in Kagoshima City was 111 ton・km^{-2}・month^{-1}, which was considerably lower than that observed in the last fiscal year by ca. 100 ton・km^{-2}・month^{-1}. The falling weights of water-soluble matter and Cl^- were similar to those for the last fiscal year, while the falling weight of SO_4^{2-} and the frequency of acidic rain were lower than those for the last fiscal year. NO_2 air pollution was measured by use of the ''Filter-badge method''. The highest value of NO_2 concentration was observed at Kagoshima City Hall, whose figure, however, met the value established as the national environmental standard