关键词: 灌丛化, 荒漠草原, 土壤有机碳, 空间预测, 人工灌丛

Abstract: Selenium (Se) was released into the surrounding environment as an associated element of mercury (Hg). When examining the Hg pollution in Wanshan Hg mining area, Guizhou Province, we should consider the presence of Se. To assess the Hg and Se levels, distribution, and their interactions in the residents in Wanshan mercury mining area, a total of 30 people were randomly selected in this study. The blood, urine, and hair samples were collected for determination of the concentrations of total mercury (THg), methylmercury (MeHg) and Se. The results showed that THg in 31% of blood samples and 93% of hair samples from the studied population exceeded the limits of 5.8 μg·L^-1 and 1 mg·kg^-1 recommended by United States Environmental Protection Agency (USEPA), respectively. Urine Hg in 24% of the studied population exceeded the limit of 5 μg·L^-1 recommended by the United Nations Industrial Development Organization (UNIDO). The results indicated that the studied population was exposed to both MeHg and inorganic Hg. Hair Se contents in 90% of the study population were at the medium and high levels. Sufficient Se in the human body may inhibit the accumulation of Hg and thusreduce the health risks of Hg exposure in local residents.

Key words: soil organic carbon, desert grassland, anthropogenically introduced shrub, shrub encroachment., spatial prediction