I was honored to be asked to contribute a chapter to the collected works within Tortured Science: Health Studies, Ethics and Nuclear Weapons in the United States, compiled and edited by Dianne Quigley, Amy Lowman, and Steve Wing, published 2012 by Baywood Publishing Company, Inc, Amityville, New York. I am very grateful that Baywood has allowed me to reprint the chapter in its entirety. The chapter is reprinted as a series of excerpts.
The very nature of the HTDS as environmental epidemiology provides another reason for the inappropriateness of the conclusions that the HTDS investigators made. Environmental epidemiology is an observational study of the effect on human health of physical, biological, and chemical factors in the external environ- ment . The aim of the HTDS was to study the effect of I-131 on thyroid disease. The HTDS can be further characterized as “risk-factor epidemiology” [88-90] because it focuses on factors associated with excess disease in groups, such as thyroid disease, but lacks the direct evidence to “specify the cause of any particular case of disease” . Risk-factor epidemiology has the capacity to produce a generalized statement about the probability or risk that members of a population have developed or will develop a given disease due to this exposure, but it is not able to deliver a definitive answer for people like my family and our former Richland neighbors who now suffer with thyroid cancer and thyroid disease. For this reason, the HTDS should never have been portrayed as a source of “reassurance” to us that our health has not been harmed by radiation emissions from Hanford.
The Hanford Health Information Network published an article that expounds on this point:
Regrettably, given the way in which the draft results of the study were communicated, the HTDS actually inflicted a good deal of harm on those whom the study was intended to serve.
The cause of this harm is not the fact that the HTDS investigators found no link between Hanford radiation and thyroid disease. The fact is, it is rare for individual epidemiologic studies to provide strong evidence for connections between low-dose exposures and diseases like cancer. More often than not, the results are inconclusive.
The problem with the January 1999 release of the HTDS is that the draft results of the study were presented as if they were conclusive. The message from the researchers was that if you are among those who suspected (or believed) that Hanford emissions are responsible for an increase in thyroid disease among downwinders, you should be “reassured” that there is no such connection. Such statements by scientists are practically unheard of in connection with environmental epidemiologic studies. The simple reason for this is that scien- tists understand that the results of any such study (whether it finds a link, or doesn’t) have to be viewed as a piece in a larger puzzle. This is because environmental epidemiology is not laboratory science where researchers conduct carefully controlled experiments that can be repeated by other scien- tists. It is an observational science, where a given hypothesis must be tested via repeated observations and evaluated within the context of animal studies,
cellular and molecular research, etc.
In the case of the HTDS, there is considerable evidence from previous studies that exposure to radioactive iodine does cause increases in thyroid diseases. Why the HTDS team would offer “reassurance” in light of this other evidence is puzzling. The mildest criticism one can offer is that their state- ments do not reflect the circumspection and caution that is the hallmark of the science [92, p. 5].
87. National Research Council’s Committee on Environmental Epidemiology’s defini- tion. See Connor, T. 1997. Burdens of proof. Energy Research Foundation, p. 11.
88. Skrabanek P. 1992. The poverty of epidemiology. Perspectives in Biology and
89. Skrabanek P. 1993. The epidemiology of errors (commentary). Lancet 342:1502.
90. Wing, S. 1994. Limits of epidemiology. Medicine and Global Survival 1:74-86.
91. Hanford Health Information Network. September 1994. Radiation health effects, A monograph study of the health effects of radiation and information concerning radioactive releases from the Hanford Site 1942-1972, p. 21, cited in Connor, T. 1997. Burdens of proof. Energy Research Foundation, p. 12.
92. Hanford Health Information Network. March 2000. Perspectives on the Hanford Thyroid Disease Study: The HTDS has done more harm than good for Hanford downwinders, p. 5.