Abstract: Concentrations of total mercury (THg), reactive mercury (RHg), and dissolved gaseous mercury (DGM) in precipitation collected from Xunyang Hg mining district in Shaanxi Province from July 2012 to Septernber 2013 were measured. The trace elements in precipitation were analyzed as well. Results showed that average concentrations of THg, RHg, and DGM were (48±43), (13±9.0), and (3.8±3.6) ng·L^-1, with ranges of 4.4-253, 0.39-43, and 0.41-17 ng·L^-1, respectively. The fractions of Hg species accounted for 27% in RHg, 7.9% DGM, and 65% in other inorganic forms. The average pH value in rain was 5.4, with a range of 4.2-6.7. Mercury in precipitation exhibited significantly positive correlation with both Sb (R²=0.54) and Se (R²=0.67), indicating a similar source of the three elements due to the Hg mining activities. However, the local coal combustion might be another important source of Hg in wet deposition far from the Hg mining region.

Key words: wheat, maize, intercropping, intercropping stage, eco-environment.