Hierarchical cluster analysis of polychlorinated dioxins and furans in Michigan, USA, soils: Evaluation of industrial and background congener profiles

Authors

  • Timothy P. Towey,

    Corresponding author
    1. Department of Civil and Environmental Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan 48109, USA
    2. LimnoTech, 501 Avis Drive, Ann Arbor, Michigan 48108, USA
    • Department of Civil and Environmental Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan 48109, USA.
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  • Shu-Chi Chang,

    1. Department of Civil and Environmental Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan 48109, USA
    2. Department of Environmental Engineering, College of Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan
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  • Avery Demond,

    1. Department of Civil and Environmental Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan 48109, USA
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  • Daniel Wright,

    1. Department of Civil and Environmental Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan 48109, USA
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  • Noémi Barabás,

    1. LimnoTech, 501 Avis Drive, Ann Arbor, Michigan 48108, USA
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  • Alfred Franzblau,

    1. Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan 48109, USA
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  • David H. Garabrant,

    1. Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan 48109, USA
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  • Brenda W. Gillespie,

    1. Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, Michigan 48109, USA
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  • James Lepkowski,

    1. University of Michigan Institute for Social Research, Ann Arbor, Michigan 48109, USA
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  • William Luksemburg,

    1. Vista Analytical Laboratory, 1100 Windfield Way, El Dorado Hills, California 95762, USA
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  • Peter Adriaens

    1. Department of Civil and Environmental Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan 48109, USA
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Abstract

As part of the University of Michigan Dioxin Exposure Study, soil samples were collected from 766 residential properties near the Tittabawassee River between Midland and Saginaw; near the Dow Chemical Facility in Midland; and, for comparison, in the other areas of Midland and Saginaw Counties and in Jackson and Calhoun Counties, all located in the state of Michigan, USA. A total of 2,081 soil samples were analyzed for 17 polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). In order to better understand the distribution and sources of the PCDD/F congeners in the study area, hierarchical cluster analysis (HCA) was used to statistically group samples with similar congener patterns. The analysis yielded a total of 13 clusters, including: 3 clusters among the soils impacted by contamination present in the Tittabawassee River sediments, a cluster comprised mainly of samples collected within the depositional area of the Dow incinerator complex, a small cluster of samples with elevated 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD), and several clusters exhibiting background patterns. The clusters related to the Tittabawassee River floodplain contamination all contained elevated PCDF levels and were differentiated from one another primarily by their relative concentrations of higher-chlorinated PCDDs, a difference likely related to both extent and timing of impacts from Tittabawassee sediments. The background clusters appear to be related to combustion processes and are differentiated, in part, by their relative fractions of TCDD. Thus, HCA was useful for identifying congener profile characteristics in both contaminated and background soil samples. Environ. Toxicol. Chem. 2010;29:64–72. © 2009 SETAC

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