Researchers from Institute of Geochemistry, Chinese Academy of Science （IGCAS）have carried out a study on the distributions of speciated atmospheric mercury at the downtown of Guiyang, one of the most polluted city in southwestern China due to the large consumptions of coal in both industrial activates and residential heating.  The study found that mercury species in ambient air of Guiyang were impacted by different emission sources.

In the study, the three major forms of atmospheric mercury, gaseous elemental mercury (GEM), reactively gaseous mercury (RGM), and particulate mercury (PHg) were continuously measured using an automatic speciated sampling unit (Tekran 2537+1130+1135).  The results indicated that the city of Guiyang exhibited highly elevated levels of speciated atmospheric mercury, with the means up to one magnitude higher than those in Europe and North America.  The Potential Source Contribution Function analysis showed that anthropogenic mercury emissions in this city contributed significantly to the elevated atmospheric mercury species.  Source identification implied GEM concentrations were primarily impacted by residential coal combustion emissions.  PHg concentrations were affected by both residential coal combustion and small-scale industrial boilers which were seldom equipped with air particle control devices.  On the other hand, RGM in ambient air mainly had the industrial sources including power plants, cement production factories, and iron/steel production factories.

The above findings have been published in Atmospheric Environment (Atmospheric Environment, 45, 4205-4212, 2011).

(By FU Xuewu)