Distribution and sources of mercury in soils from former industrialized urban areas of Beijing, China

Fifty-seven typical surface soils and 108 deeper soils were collected from five former industrial sites in Beijing and concentrations of total Hg (∑Hg) as well as pH, total carbon (TC), total nitrogen (TN), total sulfur, and dissolved organic carbon concentrations determined. The mean concentration of ∑Hg in surface soils was significantly greater than background concentrations in the vicinity of Beijing. Forty-eight percent of the samples exceeded the "critical" concentration of 1.0 mg Hg/kg, dry weight in soils, which has been established by the Chinese government. At depths of 0-80 cm in the soil, profile concentrations of ∑Hg also exceeded the background value. There were significant correlations between concentrations of ∑Hg, TC, and TN in the industrial soils. The greater concentration of ∑Hg in most soils could have been due in part to combustion of coal and leakage from industrial processes. © 2008 Springer Science+Business Media B.V.