Airborne manganese concentrations on the Korean peninsula from 1991 to 2006.

In this study, the distribution of airborne manganese (Mn) bound with particulate matters (PM) was investigated using data sets collected from 15 major cities in Korea over a 16-year time span (1991-2006). The mean Mn concentration measured from all the major cities in Korea throughout the entire study period was 71 ng m(-3), while the annual mean values of different cities ranged from 10.5 ng m(-3) in Yeosu (2003) to 615 ng m(-3) in Wonju (2006). The Mn levels were considerably larger in industrialized areas than in other land-use types. The Mn concentrations in the major industrial cities of Pohang, Incheon, and Ansan averaged 255, 98.2, and 84.6 ng m(-3), respectively; these values were far higher than those measured typically at most cities, e.g., 20-60 ng m(-3). Seasonal patterns characterized by the peak occurrence in spring and the noticeable drop in summer reflected the effects of the massive PM inflow from China (spring) and effective washout by summer monsoon in East Asia, respectively. Examination of Mn data over a long-term period indicated that the temporal trends of Mn seen in most cities were fairly constant through time since the 1990 s, although some abnormalities were observed in cities of strong man-made activities (e.g., Pohang and Wonju). In light of the severity of airborne Mn pollution in many urban areas, it is desirable to establish an abatement strategy that can help effectively reduce Mn levels.

Reduced sulfur compounds in ambient air surrounding an industrial region in Korea.

The atmospheric concentrations of several reduced sulfur compounds (RSCs) including H(2)S, CH(3)SH, DMS, CS(2), and DMDS were measured concurrently from a series of field campaigns covering multiple locations in the surroundings of a large industrial region (August 2004 to September 2005). These field studies have been designed and undertaken to inspect the concentrations of RSCs in ambient air. The RSC concentrations were found to occur in a highly variable range. H(2)S (1.06 +/- 2.07 ppb) was found to be the most abundant RSC followed by CS(2) (0.84 +/- 0.54 ppb), DMDS (0.36 +/- 1.21 ppb), DMS (0.24 +/- 0.83 ppb), and CH(3)SH (0.11 +/- 0.23 ppb). The RSC levels measured at the study area were comparable to those observed previously from other polluted environmental settings. When these RSC data were examined further in terms of spatial (industrial vs. non-industrial sites) and seasonal (summer vs. winter seasons) grouping schemes, differences in their concentration levels were statistically insignificant in most cases. In contrast, there were fairly strong variations in temporal patterns over a diurnal cycle. If these RSC concentration data were converted to diagnose the malodor strengths, their effects were in most cases insignificant with minor contribution towards odor nuisances.