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Contaminant trends in reservoir sediment cores as records of influent stream quality

Environmental Science and Technology

By:
and
DOI: 10.1021/es049859x

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Abstract

When reconstructing water-quality histories from lake and reservoir cores, it is sometimes assumed that the chemical signatures in the cores reflect historical water quality in the influent streams. To investigate this assumption, concentrations of metals, PAHs, and organochlorine compounds in sediment cores were compared to those associated with an influent-stream suspended sediment for three reservoirs in Fort Worth, TX, and two reservoirs in Boston, MA, U.S.A., and interpreted in light of land-use and regulation histories. In evaluating relations between suspended sediments and cores, three levels of preservation were indicated: (1) influent concentrations and historical trends are preserved in cores (metals at all sites; some organic contaminants at some sites); (2) some loss occurs during transport and initial deposition but relative historical trends are preserved in cores (some organic contaminants at some sites); and (3) neither stream concentrations nor relative historical trends are preserved (dieldrin and p,p???-DDT). The degree of preservation of influent concentration histories varied between lakes, particularly for PAHs. The results support the use of sediment cores to infer streamwater-quality histories for many contaminants but indicate that reservoir-bottom sediment samples might underestimate concentrations of organic contaminants in some streams.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Contaminant trends in reservoir sediment cores as records of influent stream quality
Series title:
Environmental Science and Technology
DOI:
10.1021/es049859x
Volume
38
Issue:
11
Year Published:
2004
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Science and Technology
First page:
2978
Last page:
2986
Number of Pages:
9