Characteristics in Concentration of Chemical Species in Ambient Air Based on Three-Year Monitoring by Filter Pack Method

Abstract

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+ .

Field Survey of Trans-boundary Air Pollution with High Time Resolution at Coastal Sites on the Sea of Japan during Winter in Japan}

“…Matsumoto and Okita (1998) and Matsuda et al (2002) studied the artifacts in detail. In addition, Aikawa et al (2005) also discussed the artifacts when using the four-stage filter pack method. Taking the manuscripts by Matsumoto and Okita (1998) and Matsuda et al (2002) and the previous discussion by Aikawa et al (2005), few artifacts could be observed for sulfate, and some artifacts could be observed for nitrate, ammonium, and chloride although no actual estimation of the artifacts by using a denuder method was tried in the current survey.…”

“…In addition, Aikawa et al (2005) also discussed the artifacts when using the four-stage filter pack method. Taking the manuscripts by Matsumoto and Okita (1998) and Matsuda et al (2002) and the previous discussion by Aikawa et al (2005), few artifacts could be observed for sulfate, and some artifacts could be observed for nitrate, ammonium, and chloride although no actual estimation of the artifacts by using a denuder method was tried in the current survey. However, as discussed in the manuscript by Aikawa et al (2005), the possible artifacts were presumably expected to be smaller than the results by Matsumoto and Okita (1998) due to the low air temperature in the current survey period.…”

“…The high concentration of nss-Ca 2+ (p) in the ambient air is observed in the yellow-sand events (Aikawa et al, 2005). Yellow-sand events frequently occur in March and April.…”

Estimation of the amount of dry deposition in an urban area (Kobe city, Japan) by the inferential method

“…1. The characteristics of the concentrations of chemical species in ambient air collected at the same monitoring site for 3 years, from April 1999 to March 2002, were previously studied by Aikawa et al (2005). In this work, the monthly mean concentrations of SO 2 (g) were higher in spring (March, April, and May) and summer (June, July, and August) than in autumn (September, October, and November) and winter (December, January, and February).…”

“…2. The characteristics of the HNO 3 (g) concentration in ambient air collected at the same monitoring site for 3 years, from April 1999 to March 2002, were also studied by Aikawa et al (2005), who identified that the HNO 3 (g) concentration was significantly high in summer and low in winter. The monthly mean HNO 3 (g) concentrations showed similar seasonal variations, although the monthly mean HNO 3 (g) concentrations in July and August 2002 were lower than usual.…”