title: Legacy source of mercury in an urban stream-wetland ecosystem in central North Carolina, USA.
abstract: In the United States, aquatic mercury contamination originates from point and non-point sources to watersheds. Here, we studied the contribution of mercury in urban runoff derived from historically contaminated soils and the subsequent production of methylmercury in a stream-wetland complex (Durham, North Carolina), the receiving water of this runoff. Our results demonstrated that the mercury originated from the leachate of grass-covered athletic fields. A fraction of mercury in this soil existed as phenylmercury, suggesting that mercurial anti-fungal compounds were historically applied to this soil. Further downstream in the anaerobic sediments of the stream-wetland complex, a fraction (up to 9%) of mercury was converted to methylmercury, the bioaccumulative form of the metal. Importantly, the concentrations of total mercury and methylmercury were reduced to background levels within the stream-wetland complex. Overall, this work provides an example of a legacy source of mercury that should be considered in urban watershed models and watershed management.
authors.affiliation: Duke University, Department of Civil and Environmental Engineering, Box 90287, Durham, NC 27708, USA. Electronic address: amrikadeonarine@gmail.com.
authors.forename: Amrika
authors.initials: A
authors.lastname: Deonarine
authors.affiliation: Duke University, Department of Civil and Environmental Engineering, Box 90287, Durham, NC 27708, USA.
authors.forename: Heileen
authors.initials: H
authors.lastname: Hsu-Kim
authors.affiliation: Duke University, Department of Civil and Environmental Engineering, Box 90287, Durham, NC 27708, USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Florida International University, Department of Chemistry and Biochemistry, Miami, Fl 33199, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Cai
authors.affiliation: Duke University Wetland Center, Nicholas School of the Environment, Box 90333, Durham, NC 27708, USA.
authors.forename: Curtis J
authors.initials: CJ
authors.lastname: Richardson
mesh_terms: D017753:Ecosystem; D008628:Mercury / Q000032:analysis*; D008962:Models, Theoretical; D009657:North Carolina; D009941:Organomercury Compounds / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D014507:Urbanization; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D009941:Organomercury Compounds; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Fungicide; Mercury; Methylmercury; Phenylmercury; Urban runoff; Wetland