Abstract
In early winter season, severe air pollution due to suspended particulate matter occurs frequently at South-Kanto Plain. During such episodes observed on November 26 and 27, and December 6 and 7 in 1991, intensive field observations were conducted in order to investigate the behavior and source of atmospheric particulate chlorides. Although very high concentrations of TSP, SPM2.4 (fine particles less than 2.4 μm) and chlorides were observed, very low level of seasalt chlorides were found. Thus, most of the total chlorides in suspended particulate matter were non-seasalt chlorides existing in fine particles less than 2.4 μm collected at Kanda or Urawa. The result of high correlations (significance levels higher than 99%) between [Cl-]nss and [K+] or [Cl-]nss and [Zn] calculated for SPM2.4, shows the evidence that high level of non-seasalt chlorides was the secondary products of HCl emitted from refuse incineration and/or biomass burning under the stagnation with low temperature and high relative humidity of lower layer in early winter.
