title: Spatial distribution and speciation of mercury and methyl mercury in the surface water of East River (Dongjiang) tributary of Pearl River Delta, South China.
abstract: OBJECTIVE
  The distribution and speciation of mercury in surface water of East River, Guangdong province, China were investigated.
  
  
  METHODS
  All told 63 water samples were collected during a bi-weekly sampling campaign from July 15th to 26th, 2009.
  
  
  RESULTS
  Total mercury (THg) concentrations in water samples ranged from 11 to 49 ng/L. Maximum levels of THg were measured in the lower reaches of East River, where it passes through a major industrial area adjacent to Dongguang city. Higher ratios of dissolved mercury (THg (aq)) in proportion to THg were restricted to the downstream section of East River. Concentrations of the minor constituent methyl mercury varied in the range from 0.08 to 0.21 ng/L. On average, methyl mercury made up 0.8% and 0.56% of THg (aq) and THg, respectively. Dissolved species dominated the speciation of methyl mercury in proportions up to 81%, which may imply that methyl mercury is largely produced in situ within the river water. Environmental factors (such as water temperature, dissolved oxygen, etc.) are regarded to play an important role in Hg methylation processes were monitored and assessed.
  
  
  CONCLUSIONS
  In an international perspective, East River must be classified as a polluted river with considerably sources within its industrial areas. The THg (aq) and particle mercury fluxes to the Pearl River Estuary by East River run-off were estimated to be 0.31 ± 0.11 and 0.17 ± 0.13 t/year, respectively. Hence, in total nearly 0.5 t Hg is annually released to the sea from the East River tributary.
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China.
authors.forename: Jinling
authors.initials: J
authors.lastname: Liu
authors.forename: Xinbin
authors.initials: X
authors.lastname: Feng
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.forename: Xian
authors.initials: X
authors.lastname: Zhang
authors.forename: Runsheng
authors.initials: R
authors.lastname: Yin
mesh_terms: D002681:China; D004784:Environmental Monitoring; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; C073972:dimethyl mercury; D008628:Mercury