The biogeochemical cycling of mercury in Hg mining areas in Guizhou, China

摘要

Guizhou is known as the "mercury capital" of China because more than 70% of total national Hg resources were discovered in this province and at least 12 large and super large-scale Hg mines have already been discovered and operated in the province We found that the railings and calcine from past large scale Hg mining activities are the important sources of Hg contamination to the local environment, such as surface water, soil compartment, food and vegetables. Concentrations of total Hg and methylmercury (MeHg) were measured in soil and vegetation samples collected from historic Hg-mining areas. Total Hg concentrations in soil and vegetation samples were highly elevated ranging from 0.41-610mg·kg<'-1> and from 0.02-55mg·kg<'-1>, respectively. MeHg concentrations varied from 0.41-8.8μg·kg<'-1> in soil samples and from 0.65-5.5μg·kg<'-1> in vegetations. The small scale mining activities have also resulted in serious Hg pollution to the local environment.