[Mercury exchange fluxes between air and soil interface over different type of land in Wanshan Hg mine area].

Air/soil Hg exchange fluxes were measured using field chamber-automated air mercury analyzer method over different land in Wanshan Hg mine area in two seasons. The results showed that the air/soil Hg exchange fluxes were very strong. The highest Hg emission flux from soil was 27 827 ng/(m2 x h), the highest Hg deposition flux from the atmosphere was 9 434 ng/(m2 x h). Because of Hg emission from anthropogenic activities and natural lands, the Hg concentrations in air in Wanshan Hg mine area are 1 - 3 orders of magnitude greater than background area. The highest average Hg concentration in air reached 1 101.8 ng/m3, and the lowest average Hg concentration in air still reached 17.8 ng/m3. These indicated that the atmosphere was polluted seriously in Wanshan Hg mine area. The Hg exchange fluxes are influenced by solar irradiation and the Hg concentrations in air. The solar irradiation accelerates the Hg emission from soil. Conversely, the Hg concentration in air restrained the Hg emission from soil, and even leads the Hg concentration depositing to soil surface. The Hg emission fluxes from uncovered soil are higher than that from covered soil by vegetations significantly. And the slag becomes net atmospheric Hg source.