Continuous monitoring of concentrations of particulate matter and gaseous compounds for three years by a four-stage filter-pack method clarified the characteristics in the concentrations of chemical species in particulate matter and gaseous compounds in ambient air in Kobe, Japan. The amount of materials in blank filters was low enough for this method to be used for the monitoring of ambient air. Little or none of the hydrogen chloride was derived anthropogenically. The concentrations of both particulate sulfate and sulfur dioxide in spring and summer were significantly higher than those in autumn and winter. The concentration of gaseous nitric acid was high in summer, which suggests that active photochemical reactions in the atmosphere provided more nitrogen species in summer. The measured concentration products [HNO 3 ][NH 3 ] showed good agreement with the theoretical predictions with some exceptions. The total concentration of ammonium species showed no significant seasonal variation except that the concentration in winter was low. The concentration of nss-Ca 2+ in spring was significantly higher than that in the other seasons, which is most likely associated with the so-called yellow-sand events. The concentrations of nss-K + and nss-Ca 2+ accounted for most of K + and Ca 2+ , respectively, whereas that of nss-Mg 2+ accounted for only 5% of Mg 2+ .

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Precipitation chemistry within Japan has been assessed in order to judge both the magnitudes of the concentrations and the deposition of major ions: H+, NH4+, Ca2+, K+, Mg2+, Na+, SO42, NO3−, and Cl−. A data set was obtained through an acid precipitation survey by Japan Environment Agency at 14 stations from April 1984 to March 1986. The annual average pH at each site ranged from 4.5 to 5.1 with a mean value of 4.7. The free acidity was derived both from sulfuric and nitric acids; sulfuric acid was found to contribute to 67–83% of the free acidity. The acidity was apparently lower than that expected from SO42− and NO3− levels, mainly because alkaline species, such as NH3, and Ca2+ species neutralized a certain fraction of the original acidity. This neutralization would certify the fact that SO42− and NO3− deposition were comparable to, or smaller than those in eastern North America, but the Ca2+ and NH4+ deposition within Japan exceeded that within the U. S.

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An intensive field survey, with 6-h measurement intervals, of concentrations of chemical species in particulate matter and gaseous compounds was carried out at coastal sites on the Sea of Japan during winter. The concentration variation of SO(2)(g) and HNO(3)(g) were well correlated, whereas the NH(3)(g) concentration variation had no correlation with those of SO(2)(g) and HNO(3)(g). The NH(4) (+) (p)/non-sea-salt- (nss-)SO(4) (2 -)(p) ratio in particulate matter was mainly affected by the location of the sampling site. One or more concentration peaks of nss-Ca(2 +) for survey period were observed. Backward trajectories analyses for the highest nss-Ca(2 +) concentration peaks showed some inconsistency in pathways. We consider that insufficient mixing of the atmosphere and/or insufficient time for the transported air pollutants to react with those discharged locally are the most likely explanations for the discrepancies between the measured products [HNO(3)][NH(3)] and the calculated values.