抄録
pH-values of the rainfalls sampled at Yokosuka city, Kanagawa Prefecture have been observed in about two years since May, 1991. In addition, by using liquid chromatograph apparatus, the chemical microanalyses for several anions of Cl-, NO-2, NO-3 and SO2-4 were carried out on the some of rainfalls and snowfalls sampled at Kantou and Jyouetsu districts.Based on the observation of pH and results of chemical microanalyses, some discussions are performed about the real conditions of acid rain in Kantou and Jyouetsu districts and the anion-composition of rainfalls and snowfalls.Observation at Yokosuka city shows that the acid rain whose pH is less than 5.6 accounts more than about 70% frequency of all the rainfalls during 1992. The frequency of acid rain increases every year.It is also found that almost of the rainfalls and snowfalls at Kantou and Jyouetsu districts have the concentrations of NO-3 less than 5 ppm and SO2-4 less than 10 ppm.
