Air pollution in Kagoshima City (part 2) : investigation from April 1988 to March 1989

The air pollution in Kagoshima City from April 1988 to March 1989 was investigated with paticular emphasis on the volcanic ashfall from Mt. Sakurajima. The vocanic ash was collected monthly together with rain water at eight locations in Kagoshima City. After the samples 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 ashfall at eight locations in Kagoshima Cith was 203 ton・km^{-2} a month, which was higher than that observed in the last fiscal year by 47 ton・km^{-2}. At Kagoshima City Hall, a very large amount of ashfall (6,040 ton・km^{-2} a month) was recorded in June 1988. The falling weights of SO_4^{2-}, Cl^-, and water-soluble matter as well as the frequency of acidic rain were generally lower that those for the last fiscal year. NO_2 air pollution was measured by use of the ''Filter-badge method'', and it was proven that NO_2 concentrations observed at eight locations in Kagoshima City were considerably lower than the value established as the environmental safety standard