Tempospatial Variation and Partition of Atmospheric Mercury during Wet and Dry Seasons at Sensitivity Sites within a Heavily Polluted Industrial City

This study investigated the seasonal variation and spatial distribution of total gaseous mercury (TGM) and particulate mercury (Hg-p) in the ambient atmosphere of Kaohsiung City, the largest industrial city in Taiwan, located at the coastal region of southern Taiwan. TGM and Hg-p were measured at six sensitivity sites and one coastal background site, from June to December, 2010. Field measurement results showed that the seasonal averaged concentrations of TGM and Hg-p were in the range of 2.38-9.41 and 0.02-0.59 ng/m(3) with the highest concentrations of 9.41 and 0.59 ng/m(3), respectively. Moreover, the partition of atmospheric mercury was found to be 92.71-99.17% TGM and 0.83-7.29% Hg-p. As a whole, the concentrations of mercury species in the dry season were higher than those in the wet season, for both TGM or Hg-p concentrations. The TGM and Hg-p concentrations at the Hsiao-kang site was the highest in Kaohsiung City. Hot spots of atmospheric mercury were found at two regions in Kaohsiung City, including a steel industrial complex in the south and a petrochemical industrial complex in the north. The correlation of atmospheric mercury with meteorological parameters (e.g., ambient temperature, relative humidity, and UV intensity) and air pollutants (e.g., CO, SO2, NOx, and O-3) was further discussed. The results indicated that TGM and Hg-p concentrations correlated positively with SO2, NOx, CO, ambient temperature, and UVB, and negatively with relative humidity, O-3, and wind speed.