When Using Multivariate Data Analysis Techniques to Fingerprint Sources of Polychlorinated Dibenzo-p-Doxins, Dibenzofurans, and Biphenyls in the Environment. D. Dodge, R. Wenning, and J. Beach, McLaren-Hart/ChemRisk, 1320 Harbor Bay Parkway, Suite 100, Alameda, CA 94502-6578
Several studies have shown that different polychlorinated dibenzo-p-dioxin (PCDD), dibenzofuran (PCDF), and biphenyl (PCB) sources may be characterized by different congener patterns in air, soil, sediment, and biota. A variety of multivariate data analysis techniques have been developed to address the problem of identifying (‘fingerprinting’) individual environmental sources among mixtures of persistent organic chemicals in the environment. At present, the occurrence and relative distribution of certain sets of congeners have been well characterized in the literature for many primary and secondary sources. When comparing and contrasting patterns in environmental data sets, several factors must be considered as part of a rational approach to source identification. In this paper, we use case studies and examples from the literature to describe some of the important considerations that can influence the analysis and how they may be addressed. Specific considerations include: 1) analytical issues, such as non-detect values and differences in laboratory techniques and sensitivities; 2) the influence of individual characteristics on congener patterns in human blood; 3) historic changes in industrial processes and land use characteristics at industrial sites; and 4) bioaccumulation and bioconcentration phenomena in biotic samples.
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