Characteristics and distributions of atmospheric mercury emitted from anthropogenic sources in Guiyang, southwestern China

Continuous measurements of speciated atmospheric mercury (Hg), including gaseous elemental mercury (GEM), particulate mercury (PHg), and reactive gaseous mercury (RGM) were conducted in Guizhou Province, southwestern China. Guiyang Power Plant (GPP), Guiyang Wujiang Cement Plant, Guizhou Aluminum Plant (GAP), and Guiyang Forest Park (GFP) in Guiyang were selected as study sites. Automatic Atmospheric Mercury Speciation Analyzers (Tekran 2537A) were used for GEM analysis. PHg and RGM were simultaneously collected by a manual sampling system, including elutriator, coupler/impactor, KCl-coated annular denuder, and a filter holder. Results show that different emission sources dominate different species of Hg. The highest average GEM value was 22.2 +/- 28.3 ng.m(-3) and the lowest 6.1 +/- 3.9 ng.m(-3), from samples collected at GPP and GAP, respectively. The maximum average PHg was 1984.9 pg.m(-3) and the minimum average 55.9 pg.m(-3), also from GPP and GAP, respectively. Similarly, the highest average RGM of 68.8 pg.m(-3) was measured at GPP, and the lowest level of 20.5 pg.m(-3) was found at GAP. We conclude that coal combustion sources are still playing a key role in GEM; traffic contributes significantly to PHg; and domestic pollution dominates RGM.