A Study on the Precipitation pH in Seoul Area

In order to investigate the phenomenon of acid precipitation, pH value was measured from rainwater sampled around 20 sites in Seoul area during the period of 9 months from September 1987 to August 1988(excluded December, January and February). The results are summerized as follows; 1. The mean pH at 20 sites in Seoul area during the period was 5.1 and acid rain was found in all sites. 2. During the period pH values of 3.2~6.8 were measured and pH ranging from 4.6 to 5.5 was shown to be the highest ratio of appearance (52.1%). 3. The rainwater pH was high in summer and low in other seasons. 4. The appearance ratio of pH value below 5.5 was 72% of total samples. 5. The acid precipitation in Seoul area appeared to be concentrated on certain districts such as industrial areas and traffic zones