REVIEW OF COMPLETED PROJECTS
The only completed project of the Electric and Magnetic Fields (EMF) Research and Public Information Dissemination (RAPID) program that was provided to the committee to review for the period covered by this report was the booklet Questions and Answers About Electric and Magnetic Fields Associated with the Use of Electric Power (DOE, NIEHS, 1995). This booklet appears to present objective responses, in light of current knowledge, to a variety of questions that might be asked by a concerned member of the public. With that audience in mind, the document attempts to avoid technical jargon and to simplify the responses to an extent that does not compromise accuracy. Overall, the document meets those goals, and more such booklets should be published.
The booklet builds on the tradition of information brochures produced by other agencies and universities; the authors note that much of the material provided was originally developed by the Bonneville Power Administration, one of the first federal agencies to recognize the public need for information about the science underlying the EMF issue. Other booklets that come highly recommended include EMF in Your Environment (EPA, 1992), Nonionizing Radiation Questions and Answers (Yost, 1993), and a three part series of booklets published by Carnegie Mellon University called Fields from Electric Power (Morgan, 1995). The EMF-RAPID information booklet (DOE, NIEHS, 1995), draws on previous publications, although it offers somewhat more technical and scientific depth. It is well written and professional in appearance. Education of the news media and the public about issues involving the possible health effects of EMF exposure is extremely important: In this case it is probably as important to communicate the results of research as it is to conduct the research itself. This document is an excellent first step by the communications component of the EMF-RAPID program.
Although the question and answers booklet is an excellent source of information on EMF for public dissemination, there are several areas in the document in which simplifications and generalizations have resulted in technical inaccuracies. Although these sections are not expected to
materially mislead the general reader, they might well serve as points of contention for technical readers who, for one reason or another, seek to discredit the document. There is also a small possibility that the oversimplifications might be accepted as truth by the general reader, leading to mistrust of technical practitioners who attempt to tell them otherwise. A few examples follow:
On page 5, the discussion of fields originating from alternating and direct current states that “in most practical situations, a battery-operated appliance is unlikely to induce electric current in the person using the appliance.” Although that assertion may be true for purely direct current devices such as a flashlight, it is clearly not true for appliances that have universal motors or electronic circuits. Battery-powered tools, portable televisions, and tape players all produce time-varying magnetic fields that can induce current in the human body.
On page 6, in the sidebar on fields, the orientation of the electric and magnetic fields depicted in the drawing applies to a single wire, not to a pair of wires, such as the lamp cord that is illustrated.
On page 7, the second paragraph of the answer asserts incorrectly that the amount of energy in a field is inversely proportional to its wavelength. The energy stored in the field is proportional to the square of the field strength, regardless of wavelength. The energy of individual photons of the field is proportional to frequency and, therefore, accounts for the frequency-dependent ability to ionize molecules. The ability to cook with microwaves has nothing to do with photon energy. It is merely a manifestation of the ability to efficiently propagate energy and deposit it in a target area.
The occurrence of these errors emphasizes the need to have public information booklets carefully reviewed by professional engineers and scientists charged to seek out any inaccuracy or ambiguity that might cause readers to misinterpret the information.
The booklet contains an excellent discussion of the epidemiologic data that have caused public concern. The discussion provides detailed answers to frequently asked questions and notes
the importance of statistical uncertainties in such data. Our committee believes, however, that in light of the importance of the statistical uncertainties, the confidence limits should have been included in the tables. In addition, it should have made clear that the associations being considered were, for the most part, with surrogate measures of EMF, such as job titles, and that associations were not found with measured fields.
The booklet presents only a small amount of information on laboratory studies of the effects of exposure to power frequency EMF on biologic systems. Furthermore, the health effects that might result from changes in cells, and to some extent from experiments with animals, are related to possible human health effects only through complex arguments that can be explained through detailed discussions beyond the scope of the booklet.
The discussion of melatonin is appropriate both because it has potential as a mechanism by which EMF exposure can produce a wide range of biologic effects and because it has received considerable publicity. This potential mechanism is described reasonably well. The lack of effect in some experiments is noted, and the difficulty in extrapolating across species is suggested. However, differences in exposure conditions among experiments are not noted, and positive results from experiments with hamsters, rats, and nonhuman primates are not included.
It would be useful to prepare a resource guide to provide a more comprehensive description of the biologic effects observed in the laboratory from exposure to power frequency EMF. It should be written at the same general level as the first booklet, and it should offer a careful review of the literature from in vitro and in vivo studies to provide a more comprehensive and accurate summary of current knowledge, including areas of uncertainty. This effort also could be structured as a resource for those who wish to read the primary references.