Air Pollution in Kagoshima City (Part 25) : Investigation from April 2010 to March 2011

Air pollution in Kagoshima City from April 2011 to March 2012 was investigated with particular emphasis on the falling dust (volcanic ash fall) from Mt. Sakurajima. The falling dust was collected monthly with rainwater 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 the eight locations in Kagoshima City was 97.9 g·m^{-2}·month^{-1}, which was about 1.6 times as much as that observed in the last fiscal year, and was the highest since 1993. The concentration of NO_2 in the air was measured by use of the "filter-badge method". The average NO_2 concentration at the eight locations was 7.3 ppb, which was somewhat lower than that for the last year