title: Spatial distribution of mercury in the sediments and riparian environment of the River Yare, Norfolk, UK.
abstract: Concentrations of total mercury (T-Hg) were determined in sediments and riparian (bankside) soils from the River Yare, Norfolk, UK to assess the current extent of contamination arising from a historical point source discharge. The results demonstrate that the spatial distribution pattern in surficial sediments and soils follows that of a distinct pollution plume with an initial increase 2-3 km downstream from the point source discharge at Whitlingham Sewage Treatment Works (STW) outfall. Average T-Hg concentrations in the surficial sediments ranged from 0.1 to 8.13 mg kg(-1); bankside soil concentrations ranged from 0.1 to 2.63 mg kg(-1). There has been a decline in downstream background sediment concentrations of Hg over time. This is likely to be the result of burial by fresh relatively uncontaminated sediments and possibly in the lower reach as a consequence of the influence of the freshwater-saline interface occurring near Cantley. Channel morphology was also shown to be an important factor in determining the large variations of Hg concentrations between sample points within transects. The predominant source of Hg to the soils appears to be due to dredging and the deposition of sediments during flooding.
authors.affiliation: Environmental Processes and Water Technology Group, T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College of Science, Technology and Medicine, London, UK.
authors.forename: J W
authors.initials: JW
authors.lastname: Birkett
authors.forename: J M K
authors.initials: JM
authors.lastname: Noreng
authors.forename: J N
authors.initials: JN
authors.lastname: Lester
mesh_terms: D004190:Disasters; D017753:Ecosystem; D004739:England; D019015:Geologic Sediments / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D014197:Trees; D014872:Water Movements; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D012989:Soil Pollutants; D014873:Water Pollutants; D008628:Mercury