Register      Login
Environmental Chemistry Environmental Chemistry Society
Environmental problems - Chemical approaches
Shopping Cart: ( empty )
You are here: Home > Journals > EN > EN09006
RESEARCH ARTICLE
Contents Vol 6(3)

Legacy sources of mercury in an urbanised watershed

Heather F. Clark A B and Gaboury Benoit A
+ Author Affiliations
- Author Affiliations

A Yale School of Forestry and Environmental Studies, 195 Prospect Street, New Haven, CT 06511, USA.

B Corresponding author. Email: heather.clark@yale.edu

Environmental Chemistry 6(3) 235-244 https://doi.org/10.1071/EN09006
Submitted: 14 January 2009  Accepted: 15 April 2009   Published: 18 June 2009

Environmental context. Mercury is a neurotoxin that bioaccumulates and is associated with global contamination and often with regional atmospheric sources. However, in Connecticut, USA, in watersheds characterised by a gradient of forested to urban land uses we found that the predominant source of elevated Hg is local. This study uses a novel nested sampling method to pinpoint hot spots of mercury and presents inorganic mercury concentrations in water, sediment, soil, and aquatic organisms. The results indicate that mercury contamination is an environmental legacy associated with the silver plating industry and that local sources are critical to the biogeochemical mercury cycle here.

Abstract. Mercury levels were measured in various environmental compartments of the Quinnipiac River system (CT, USA). In streams, dissolved mercury reached a maximum of 6.3 ng L–1 during baseflow and 30 ng L–1 during stormflow, whereas surficial impoundment sediments had a maximum mercury concentration of 420 μg kg–1. A sediment core collected from the Quinnipiac River indicates that peak loading of mercury occurred before 1940. Wharton Brook tributary of the Quinnipiac River represents 30% of the mercury loading to the river and the likely source of mercury to the sediment is a past silver manufacturing plant. Analysis of soil samples from the riparian zone of Wharton Brook, a tributary of concern because it empties into a popular fishing location, revealed mercury concentrations as high as 20 000 μg kg–1. It appears that the soil surrounding the former factory is acting as the current source of mercury to the water column and aquatic communities. Removal of contaminated soil will probably be necessary to reduce mercury levels and the threat to humans in downstream environments.

Additional keywords: Connecticut, hot spot, mercury, Quinnipiac River, silver plating, urban watershed.


Acknowledgements

This research was funded by the Quinnipiac River Fund of the Community Foundation for Greater New Haven and Yale Institute for Biospheric Studies. The authors thank Christopher Ziemba and Zuzana Culakova for their contribution to the field work and data. Tim F. Rozan helped collect the core from Hanover Pond and assisted with analysing its Pb, Ag, and 210Pb.


References


[1]   M. E. Brigham , D. A. Wentz , G. R. Aiken , D. P. Krabbenhoft , Mercury cycling in stream ecosystems. 1. Water column chemistry and transport. Environ. Sci. Technol. 2009 , 43,  2720.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  [Verified 12 May 2009]

[17]   A. D. Oliveira , A. Bocio , T. M. B. Trevilato , A. M. M. Takayanagui , J. L. Doming , S. I. Segura-Munoz , Heavy metals in untreated/treated urban effluent and sludge from a biological wastewater treatment plant. Environ. Sci. Pollut. R. 2007 , 14,  483.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  [Verified 12 May 2009]

[30]   Pennsylvania Department of Environmental Protection, Mercury managing, recycling, and disposing. Pollution Prevention Partnership for Environmental Responsibility in Erie 2008. Available at www.dep.state.pa.us/dep/deputate/pollprev/p3ERIE/mercbroch.pdf [Verified 12 May 2009]

[31]   Wisconsin Department of Natural Resources, Wisconsin Mercury Sourcebook 1997. Available at http://www.glrppr.org/docs/mercury_in_industry.htm [Verified 12 May 2009]

[32]   M. Ajmal , A. M. Sulaiman , A. H. Khan , Surface entrapment of toxic metals from electroplating waste and their possible recovery. Water Air Soil Pollut. 1993 , 68,  485.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  [Verified 12 May 2009]

[34]   US Environmental Protection Agency, Mercury Study Report to Congress. EPA-452/R-97-004 1997 (US Environmental Protection Agency: Washington, DC).

[35]   G. Benoit , Clean technique measurement of Pb, Ag, and Cd in fresh-water – a redefinition of metal pollution. Environ. Sci. Technol. 1994 , 28,  1987.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[36]   N. Bloom , W. F. Fitzgerald , Determination of volatile mercury species at the picogram level by low-temperature gas-chromatography with cold-vapor atomic fluorescence detection. Anal. Chim. Acta 1988 , 208,  151.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[37]   R. Schiff , G. Benoit , Effects of impervious cover at multiple spatial scales on coastal watershed streams. J. Am. Water Resour. Assoc. 2007 , 43,  712.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[38]   S. Krishnaswamy , D. Lal , J. M. Martin , M. Meybeck , Geochronology of lake sediments. Earth Planet. Sci. Lett. 1971 , 11,  407.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1