title: Mercury speciation and dispersion from an active gold mine at the West Wits area, South Africa.
abstract: Total mercury (HgTOT), inorganic mercury (IHg), and methylmercury (MHg) were determined in dry season waters, sediments, and tailings from an active mine which has long history of gold exploitation. Although HgTOT in waters was generally low (0.03 to 19.60 ng L(-1)), the majority of the samples had proportions of MHg of at least 90 % of HgTOT which denotes a substantial methylation potential of the mine watersheds. Mercury was relatively high in tailing materials (up to 867 μg kg(-1)) and also in the mine sediments (up to 837 μg kg(-1)) especially in samples collected near tailing storage facilities and within a receiving water dam. Sediment profiles revealed mercury enrichment and enhanced methylation rate at deeper layers. The presence of IHg and decaying plants (organic matter) in the watersheds as well as the anoxic conditions of bulk sediments are believed to be some of the key factors favoring the mercury methylation at the site.
authors.affiliation: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand P. Bag X3, WITS 2050, Johannesburg, South Africa.
authors.forename: J G
authors.initials: JG
authors.lastname: Lusilao-Makiese
authors.affiliation: Université de Pau et des Pays de l'Adour; LCABIE-IPREM; CNRS UMR 5254 Hélioparc, 64053, Pau, France.
authors.forename: E
authors.initials: E
authors.lastname: Tessier
authors.affiliation: Université de Pau et des Pays de l'Adour; LCABIE-IPREM; CNRS UMR 5254 Hélioparc, 64053, Pau, France.
authors.forename: D
authors.initials: D
authors.lastname: Amouroux
authors.affiliation: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand P. Bag X3, WITS 2050, Johannesburg, South Africa.
authors.forename: H
authors.initials: H
authors.lastname: Tutu
authors.affiliation: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand P. Bag X3, WITS 2050, Johannesburg, South Africa.
authors.forename: L
authors.initials: L
authors.lastname: Chimuka
authors.affiliation: School of Animal, Plant and Environmental Sciences (APES), University of the Witwatersrand P. Bag X3, WITS 2050, Johannesburg, South Africa.
authors.forename: I
authors.initials: I
authors.lastname: Weiersbye
authors.affiliation: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand P. Bag X3, WITS 2050, Johannesburg, South Africa. ewa.cukrowska@wits.ac.za.
authors.forename: E M
authors.initials: EM
authors.lastname: Cukrowska
mesh_terms: D004784:Environmental Monitoring; D005618:Fresh Water; D019015:Geologic Sediments; D006046:Gold; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds; D008906:Mining; D013019:South Africa; D014867:Water; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D014867:Water; D006046:Gold; D008628:Mercury
keywords: Gold mine; Mercury; Methylation; Speciation; Tailings