Contaminant Trends in Freshwater Fish from the Laurentian Great Lakes: A 20-Year Analysis

ABSTRACT

Although dietary concerns of Laurentian Great Lakes (GL) fish focus on the risk from persistent bioaccumulative toxicant (PBT) contaminants, fish are also an important source of nutrients beneficial to human health such as polyunsaturated fatty acids (e.g., eicosapentanoic acid and docosahexanoic acid). This study presents PBT trend data from the GL tribal fisheries over the past 20 years. PBT contaminants (282 analytes) from fillet portions of lake trout and whitefish were analyzed for trending patterns from 1992 to 2011 and are reported on five of the ATSDR/USEPA Great Lakes biomonitoring legacy contaminants (Hg, ΣDDE, ΣDDT, HCB, mirex, and ΣPCBs), two of the optional biomonitoring PBTs (toxaphene and Σdioxins/furans) and PCB 153 as a specific congener marker. Similar to other recent reports our data indicate that most PBT contaminant concentrations in the GL biota have decreased, which may indicate progress in reducing environmental emissions. Our research confirms that all contaminants demonstrate significant declines except Hg and toxaphene. Both of those remained constant after correcting for known independent factors of age, lipid, and size. These results are potentially encouraging and may provide useful data for the long distance and perhaps global influences of PBTs on the safety of fish consumption.

Key Words:

• fish
• Great Lakes
• contaminants
• PBTs
• risk communication

ACKNOWLEDGMENTS

The authors thank Paul Wangerin for his statistical consultations in the preparation of this article. The tribal fishing families, the Sault Ste. Marie Tribe, and the Chippewa Ottawa Resource Authority have dedicated two decades of work to collecting these data. Tribal resources provided most of the analytical support in addition to partial support from the Agency for Toxic Substances and Disease Registry's Great Lakes Human Health Effects program, and the Indian Health Service's Native American Research Centers for Health program with Dr. Dellinger as the principal investigator. Former graduate students (Dr. Shawn Gerstenberger and Dr. Matthew Dellinger) used parts of the early analytical results in their dissertations. We especially thank our co-author Mr. Michael Moths, who used this article in partial fulfillment of his Master of Science Degree at the University of Wisconsin in Milwaukee, but in reality he went way beyond the normal expectations and served as a catalyst to reach the final article.