Posted on November 13, 2015 by Angus Macbeth
For those of you who are becoming exhausted by the opinions in the Fox River case, it is time to suggest that the fundamental underpinning of the case – the toxicity of PCBs to humans and to fish – may be in jeopardy.
Twice under the auspices of the World Health Organization “consensus toxicity factors” for dioxin-like compounds including PCBs have been published. These factors were based on analysis of laboratory animals, typically rodents. The lead author of both reports was Martin van den Berg.
Recently an article was published in Chemical Research in Toxicology, “Consensus toxicity factors for PCPDs, PCDFs, and PCBs combining in silico models and extensive in vitro screening of AhR-mediated effects in human and rodent cells,” where van den Berg was the second author on the article who reported on the results of dosing human cells with PCBs and found that PCB 126 was the only PCB congener that produced a measurable response from human cells and that the result was more than 30 times lower than the WHO TEF value for PCB 126. Similar results have been reported in other papers.
As to fish, T.B. Henry has recently published analysis in Critical Reviews in Toxicology , “Ecotoxicology of polychlorinated biphenyls in fish – a critical review.” He concludes: “Biological activity of PCBs is limited to a small proportion of PCB congeners [e.g., dioxin-like PCBs…] and occurs at concentrations that are typically orders of magnitude higher than PCB levels detected in wild fish… Overall, there appears to be little evidence that PCBs have had any widespread effect on the health or survival of wild fish.”
What would the District Court and the Seventh Circuit make of this adjustment to the facts of the case?