Powerline Frequency Electric and Magnetic Fields: A Pilot Study of Risk Perception

The perception of the potential risk arising from human exposure to 50/60 Hz electric and magnetic fields was studied with a quasi-random sample of 116 well-educated, opinion leaders using the risk perception framework previously developed by Slovic, Fischhoff, and Lichtenstein. These individuals rated exposure to fields from transmission lines and electric blankets on a variety of scales that have been found useful in characterizing people's risk attitudes and perceptions. These judgments allowed us to conjecture about the likely desire for regulation of these potential hazards and the likely response to a publicized problem (e.g., an accident or ominous research finding) involving these two sources of exposure. Various forms of detailed information about 50/60 Hz fields were supplied to respondents. The provision of information produced modest, but statistically significant, changes in perceptions in the direction of greater concern about the risks. In response to questions of public policy, participants desired modest regulatory control of field exposure from transmission lines and little or no control of field exposure from appliances like electric blankets.     

Thyroid Cancer Risk from Exposure to Ionizing Radiation: A Case Study in the Comparative Potency Model

Considerable controversy exists about the relative risk of thyroid cancer following exposure to external radiation compared to the risk after exposure to internally deposited 131I. The human epidemiological data are equivocal, and studies are not directly comparable owing to differing ages at exposure, dose ranges, and periods of follow-up. Limited experimental data at low dose ranges support the hypothesis of equal potency in animals. This report utilizes a relative potency model to reconcile data from different sources, and to provide an estimate of thyroid cancer risk following human exposure to 131I. We utilize data from epidemiological studies of external radiation and 131I exposure in humans and data from an experimental animal study. This analysis shows that the data provide no compelling evidence to suggest that the risks accompanying external radiation or 131I exposure are different.