Human cost burden of exposure to endocrine disrupting chemicals. A critical review

Gregory G. Bond, Daniel R. Dietrich

Recently published papers have alleged that exposures to endocrine disrupting chemicals (EDCs) are causing substantial disease burdens in the EU and US and are consequently costing society hundreds of billions of dollars annually. To date, these cost estimates have not undergone adequate scientific scrutiny, but nevertheless are being used aggressively in advocacy campaigns in an attempt to fundamentally change how chemicals are tested, evaluated and regulated. Consequently, we critically evaluated the underlying methodology and assumptions employed by the chief architects of the disease burden cost estimates. Since the vast majority of their assigned disease burden costs are driven by the assumption that "loss of IQ" and "increased prevalence of intellectual disability" are caused by exposures to organophosphate pesticides (OPPs) and brominated flame retardants (PBDEs), we have taken special care in describing and evaluating the underlying toxicology and epidemiology evidence that was relied upon. Unfortunately, our review uncovered substantial flaws in the approach taken and the conclusions that were drawn. Indeed, the authors of these papers assumed causal relationships between putative exposures to EDCs and selected diseases, i.e., "loss of IQ" and "increased prevalence of intellectual disability", despite not having established them via a thorough evaluation of the strengths and weaknesses of the underlying animal toxicology and human epidemiology evidence. Consequently, the assigned disease burden costs are highly speculative and should not be considered in the weight of evidence approach underlying any serious policy discussions serving to protect the public and regulate chemicals considered as EDCs.