title: Mercury concentrations in forest soils and stream waters in northeast and south China.
abstract: Atmospheric deposition of mercury (Hg) is generally higher in China than in North America and Europe. Transport and methylation of Hg deposited in forest ecosystems may cause health risks to humans. We collected water samples from 117 small streams, and soil samples from 25 sites in forested areas in northeast and south China during 2011-2013 to investigate the spatial distribution of Hg. Results showed that Hg concentration in surface soil (0-5 cm in depth) was generally higher in south China (97.8 ± 36.0 μg/kg) than that in the northeast (44.0 ± 14.1 μg/kg). In contrast, the Hg concentration in stream water was higher in northeast China (17.2 ± 11.0 ng/L) than that in the south (6.2 ± 6.4 ng/L). Hg concentrations in surface soil were positively correlated with Hg concentrations in the overlying litter Oe/Oa horizon (r(2)=0.84). Hg concentrations in stream water were positively correlated to DOC (dissolved organic carbon) concentrations (r(2)=0.43) and to the Hg concentration in the litter Oe/Oa horizon (r(2)=0.69). Because the litter Oe/Oa horizon represents Hg accumulated by foliage, the positive correlations indicate that atmospheric Hg deposition was an important factor affecting Hg concentrations in soils and stream water.
authors: State Key laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Yao
authors: Y
authors: Luo
authors: State Key laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Collaborative Innovation Centre for Regional Environmental Quality, Tsinghua University, Beijing 100084, China. Electronic address: lduan@tsinghua.edu.cn.
authors: Lei
authors: L
authors: Duan
authors: State Key laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Long
authors: L
authors: Wang
authors: State Key laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
authors: Guangyi
authors: G
authors: Xu
authors: State Key laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Collaborative Innovation Centre for Regional Environmental Quality, Tsinghua University, Beijing 100084, China.
authors: Shuxiao
authors: S
authors: Wang
authors: State Key laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Collaborative Innovation Centre for Regional Environmental Quality, Tsinghua University, Beijing 100084, China.
authors: Jiming
authors: J
authors: Hao
mesh_terms: D002681:China; D004784:Environmental Monitoring; D065928:Forests; D008628:Mercury / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Atmospheric deposition; Dissolved organic carbon (DOC); Forest soil; Mercury; Stream water; Total organic carbon (TOC)