IV. DHS Report
In 2002, pursuant to I.91-01-012, DHS released its final report reviewing scientific studies on the health effects of EMF exposure. The findings have caused controversy, and there is no consensus among the three scientists regarding their conclusions. By reviewing numerous epidemiological studies as well as by using a "Qualitative Bayesian Approach"3 the panel of DHS scientists found that EMF exposure can, to some degree, correlate with some increased risk of childhood leukemia, adult brain cancer, Lou Gehrig's Disease, and miscarriage (see Appendix A and Appendix B.) The three DHS scientists also differed in their opinions concerning the connection of EMFs with other diseases. For example, one scientist was "prone to believe" and two were "close to the dividing line between believing and not believing" that EMFs could cause some degree of increased risk for adult leukemia. All three were undecided about the role of EMFs in the risk of suicide. The three scientists were inclined to believe that EMF exposure does not cause an increased risk of breast cancer, heart disease, Alzheimer's disease, or depression. They strongly believed that EMFs do not increase the risk of birth defects or lower birth weight, and that EMFs are not a universal carcinogen (see Appendix C).
It should be noted that the three DHS scientists' conclusions regarding the potential link between EMF exposure and associated health effects conflict with other scientific panels such as the NIEHS, IARC, and the NRPB to varying degrees (2002 Final DHS Report). One explanation for this disagreement regarding human health effects from EMF exposure is that the three DHS scientists gave credence to evidence that links adult brain cancer and miscarriage, whereas the other scientific panels considered this evidence inappropriate. Essentially, the DHS reviewers have more confidence in epidemiological data than animal or mechanistic studies, which they considered to have methodological flaws. As noted earlier, these types of studies tend to suggest a weak correlation at best between EMF exposure and health effects (2002 DHS Report, p. 9.) Regardless of which study or methodological process used, the consensus of the scientific community suggests that there is a great deal of uncertainty regarding determining either an association or a direct causation of human health effects due to EMF exposure (1999 DHS Short Fact Sheet on EMF.)
The 2002 DHS EMF report suggests that generally it may not be possible for the majority of the population to avoid some form of EMF exposure. The report also acknowledges that given the same set of data it is possible that other scientists may weigh and interpret the scientific data differently. The panel also agreed that there is not a well-documented mechanism that explains how exposure to the various sources of EMFs would cause a biological response that in turn leads to human health effects. There are numerous factors that have to be evaluated in determining a conclusive link between exposure to an agent that may possibly create carcinogenic effects or other human health impacts. For example, a scientist may account for the likelihood of a potential health effect from exposure, flaws in a study's methodology, the likelihood of other contributing factors, as well as other possibilities that may skew a result (2002 DHS Report, p. 56-57).
An independent review of the DHS study suggests that other reviewers might have reached different conclusions. In a letter to Dr. Diana Bonta, Director of DHS, Dr. Warren Winkelstein, Chairman of the Scientific Advisory Board Panel (SAP), (that reviewed the 2002 DHS Report on EMF) suggests that some members of the SAP believed that if they had reviewed the same evidence using the same assessment techniques that they might have had less confidence that there are human health effects from exposure to EMF. The lack of biological effects from exposure to EMFs demonstrated in animal models, lack of consistent dose-responses, and the possibility of other plausible contributing factors were some of the reasons that explained the different views by some of the SAP's members.
3 The Qualitative Bayesian Approach was used by the three DHS scientists to explain their judgments regarding each purported health impact from human exposure to EMFs. It acknowledges that each reviewer may have had a pre-existing viewpoint about the certainty of each potential health effect from exposure to EMFs which may be later revised based on the reviewer's subsequent review of a scientific study.
