June 24, 1998
24 Jun 1998: Panel Evaluates Electric and Magnetic Fields for Health Effects
An international panel of experts convened by the National Institute of Environmental Health Sciences reported to the institute today that electric and magnetic fields like those surrounding electric power lines should be regarded as a "possible human carcinogen."
The panel vote 19 to 9 was based largely on epidemiological evidence in the face of animal and other laboratory studies that the panel agreed did not support or refute the population studies. Because of the conflicting studies, eight members found the EMF fields not classifiable as to carcinogenicity, while one member of the panel said EMF probably is not carcinogenic to humans.
Two long-term studies in rodents demonstrated no carcinogenic response, while one showed an equivocal response in one sex of one species. The panel said that neither these studies or other lab work proved or refuted the epidemiology.
The epidemiological studies showed a slight increase in childhood leukemia risk from power line/residential exposures and an increase in chronic leukemia risk in adults in electricity-intensive industries.
"This report does not suggest that the risk is high" said, chairman Michael Gallo, Ph.D., professor and center director at the University of Medicine and Dentistry of New Jersey-Robert Wood Medical School in Piscataway, N.J. "It is probably quite small, compared to many other public health risks. However, I strongly believe that additional hypothesis-driven, focused research should be pursued to reduce uncertainties in this arena."
The scientists' report will be utilized by NIEHS in preparing a report to Congress and the federal regulatory agencies surveying the state of research on the potential health effects from exposure to power-line frequency electric and magnetic fields.
The panel found inadequate evidence in various studies for a link to such non-cancer diseases as Alzheimer's, depression and birth defects, and no clear evidence of danger of abortion from video display terminals. "There is inadequate evidence," the panel said, "for carcinogenicity to adults of residential exposure to extremely low frequency magnetic fields." And the panel found the data linking children's cancers other than leukemia to be inadequate.
Convened by the National Institute of Environmental Health Sciences, one of the National Institutes of Health, the panel was comprised of about 20 researchers in electrical and magnetic fields, or EMF, and ten scientists from other fields.
Hundreds of studies in animals and cells were considered in the evaluation as part of the evidence for potential human effects. Many of these studies showed little or no effect, raising questions about the weak associations seen in some epidemiologic studies. But the international criteria agreed upon gave great weight to human carcinogenicity.
The panel began this review six months ago when members prepared summaries of the data. They convened ten days ago in Brooklyn Park, a suburb of Minneapolis, where they debated the quality and meaning of the scientific evidence. Some of the expert panel members came from Sweden, Japan, Italy and France. After a further public comment period, NIEHS Director Kenneth Olden, Ph.D., will use the report as he prepares his own report to Congress on the issue.
Congress and industry have accelerated EMF research over the past six years, with Congress appropriating $23 million and the electrical industry matching it. NIEHS used an additional $10 million of its own appropriated funds to supplement the research as needed.
Public concern about EMF and cancer was stimulated by a 1979 study in Denver, Colo., that found that a group of children who had died from leukemia and other cancers were two to three times more likely to have lived within 131 feet of a high current electrical transmission or distribution line. A 1995 publication lists 14 such studies-eight of them showing a possible link to some cancers but only four of them at levels considered statistically significant. The nine studies considered best by the panel were used for their evaluation.
The concern eventually encompassed electric blankets for children and other appliances, as well as the wiring in homes and the very high levels of EMF in some industries. (Electric blankets and some other appliances have been redesigned, greatly reducing their EMF.)
Although the Department of Energy and the NIEHS, a part of the National Institutes of Health, already had been conducting and supporting some EMF-related research, Congress accelerated the work under a program called EMF/RAPID.
While epidemiological studies continued to try to clarify possible effects in people, EMF/RAPID concentrated on studies in biological systems, fowl and rodents that might support or contradict an EMF effect.
Other studies considered by the panel of experts were performed on cells, and computer simulations were also used.
A copy of the report, or a non-technical summary, will be available in late July and can be requested by writing EMF/RAPID, NIEHS, PO Box 12233, Research Triangle Park, NC 27709. The report and summary will also be on the EMF/RAPID web site: Electric & Magnetic Fields (http://www.niehs.nih.gov/health/topics/agents/emf/index.cfm) (http://www.niehs.nih.govhttp://edit:9992/Rhythmyx/assembler/render?sys_authtype=0&sys_variantid=925&sys_revision=10&sys_contentid=9476&sys_context=0) .
Public comments on the report agreed to today will be sought for two months. There will also be hearings for public comment in San Francisco, Chicago and Washington in August (planning continues) and in Tucson, Ariz., Sept. 14-15.
Research on EMF-related issues is likely to continue. Its focus may be re-directed on the advice of the expert panel and others. NIEHS Director Olden's report to Congress is not required by law to follow the views of the experts but their views, requested by NIEHS, are likely to get great weight.
Arnold L. Brown, M.D., of the University of Wisconsin at Madison, was vice chair. The panel was convened and organized by Christopher J. Portier, Ph.D., chief of the Laboratory of Computational Biology and Risk Analysis at the NIEHS, with advice from the National EMF Interagency Committee chaired by Shirley D. Linde of Los Angeles, and the National EMF Interagency Committee representing 11 federal regulatory agencies. Some of the experts have done research on EMF while others have distinguished themselves in other research fields. The scientists were assembled from organizations in Sweden, France, Japan and Italy as well as from Battelle Pacific Northwest Laboratory in Richland, Wash., the National Institute for Occupational Safety and Health in Cincinnati, Ohio, Northwestern University Medical School in Chicago, the Oak Ridge National Laboratory in Tennessee, the Midwest Research Institute in Kansas City, Mo., the State University of New York at Stony Brook, and the Johns Hopkins University in Baltimore, Md.
Members of national advisory groups, members of the public and the press observed the discussions throughout the lengthy, open meeting.
Shellfish Toxin Study Provides Possible Clue to Cystic Fibrosis Therapy (http://www.niehs.nih.gov/news/newsroom/releases/1998/july21/index.cfm)
New Journal Issue Updates Alternative Testing Advances (http://www.niehs.nih.gov/news/newsroom/releases/1998/june22/index.cfm)