title: Spatial trend and pollution assessment of total mercury and methylmercury pollution in the Pearl River Delta soil, South China.
abstract: Total mercury (THg) and methylmercury (MeHg) were measured in large number of soil samples collected from areas with different types of land use, different depth in the Pearl River Delta (PRD) of South China. THg and MeHg concentrations ranged from 16.7 to 3320ngg(-1) and 0.01 to 1.34ngg(-1), respectively. THg levels are highest in the top 0-20cm soil layer, and decrease from the surface to bottom layer soil. Spatial variation was observed with different types of land use. Urban parks had the highest concentrations and the other areas tended to decrease in the order of residential areas, industrial areas, vegetable fields, cereal fields, and woodlands. Temporal variation was also noted, and two relatively high THg contamination zones located in the northwestern part of the PRD have significantly expanded over the last two decades. Both THg and MeHg concentrations were correlated significantly with soil organic matter (OM), but not with soil pH. THg pollution status was evaluated using two assessment methods.
authors.affiliation: Center for Research on Urban Environment, South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou, China. chenlaiguo@scies.org
authors.forename: Laiguo
authors.initials: L
authors.lastname: Chen
authors.forename: Zhencheng
authors.initials: Z
authors.lastname: Xu
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Ding
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhang
authors.forename: Yumei
authors.initials: Y
authors.lastname: Huang
authors.forename: Ruifang
authors.initials: R
authors.lastname: Fan
authors.forename: Jiaren
authors.initials: J
authors.lastname: Sun
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.forename: Donglin
authors.initials: D
authors.lastname: Qian
authors.forename: Yongbin
authors.initials: Y
authors.lastname: Feng
mesh_terms: D002681:China; D006863:Hydrogen-Ion Concentration; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D013997:Time Factors; D014876:Water Pollution / Q000706:statistics & numerical data*
chemical_list: D008767:Methylmercury Compounds; D012987:Soil; D008628:Mercury