Abstract: Samples of top soil and air around two coal-fired power plants in Shanghai were collected, and their mercury (Hg) concentrations were determined, aimed to study the effects of flue gas Hg emission from the power plants on their peripheral environment. An atmospheric dispersion model was used to predict the ground level concentration of Hg dispersed continuously down from the point source of high stack. The Hg concentrations in the air around power plants G and J were 9.7-15.6 ng·m^-3 and 15.2-22.9 ng·m^-3, the ground level concentrations of gaseous element Hg were 0.218 ng·m^-3 and 3.034 ng·m^-3, and the ground level concentrations of particulate Hg were 0.038 ng·m^-3 and 1.199 ng·m^-3, respectively. The Hg concentrations in the top soils around power plants G and J were 36.3-136.5 ng·g^-1 and 44.3-115.9 ng·g^-1, and the Hg concentrations in plant leaves were 215.3-342.3 ng·g^-1 and 223.4-396.9 ng·g^-1, respectively. Both the field monitoring and the model estimate showed that the flue gas emission from the coal-fired power plants contributed to the distribution and accumulation of Hg in the peripheral environment.

Key words: Gross mineralization, Gross nitrification, Grasslands, ¹⁵N isotope