Abstract
In order to access the present atmospheric environment related to a planned 1.4 million KW coal power plant, the NO2 concentration in the atmosphere was measured with a TEA capsule at fourteen sites in the eastern area of Kobe during a one year period from 1. Apr. 1997 to 31. Mar. 1998. The following results were determined.
Firstly the average annual NO2 concentrations measured around the Osaka bay area were higher than those determined at sites around the foot of the Rokko mountains.
Secondly thirteen sites could be classified into four groups (Spring-type: 6, Summer: 1, Autumn: 1 and Winter: 5) from the maximum value of seasonal NO2 concentration at the site. Variations in the monthly concentrations correlated well among sites of the same type.
Thirdly the frequency of sites where the daily NO2 concentration exceeded more than 40 ppb totalled 20-29% of all sites was defined as 51 by year; the frequency of a total of 30-39% of all sites was defined as S2, the frequency of 40-49% of all sites was defined as S3 and the frequency of 50%-was S4, so that, S4 was 11 days and the total from 51 to S4 was 105 days. The total of S1-S4 in Mar. and Apr. was 33 days, and 70% was in the S2-S4 periods. Further, weather conditions in the S1-S4 groups in Apr. and Oct. were anticyclone during 80% of the period.
