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Reporting on Electromagnetic Fields and Possible Health Risks

Introduction

Few subjects an environmental journalist will cover are more emotion-driven and controversial than concerns over the possible health effects of electromagnetic fields.

It is an area where some journalists have played a large role in raising scientific and policy questions. It’s also an area where a lot of research has produced repeated consensus statements from the scientific establishment suggesting there is little persuasive evidence of important health risks. Yet journalists have continued to echo activists’ concerns in a manner that itself raises questions.

On the one hand, some have alleged a "cover-up" of evidence of harmful health effects. On the other, there may be a question of whether the media’s financial need for scare stories makes scientific evidence an inconvenient nuisance. To the conspiratorial mentality, lack of evidence is merely proof of a cover-up.

At the center of the controversy for many years was Paul Brodeur, who covered the environment for New Yorker magazine, and who authored a series of articles on EMFs in that magazine in 1989-92. Brodeur was called by ENN "the dean of environmental journalism in this country" -- and a "reporter who has made his career by digging up massive conspiracies" by skeptic Michael Fumento and was featured on the "Quackwatch" Web site. His work was published in book form as Currents of Death (1989) and The Great Power Line Cover Up (1993).

What’s an EMF?

Electric currents produce both electric and magnetic fields, but the ones of concern for this backgrounder are magnetic fields -- such as that produced by a compass needle, which aligns it with the far larger magnetic field of Earth itself. Electromagnetic fields (EMFs) are produced by the closing and opening of any electric circuit and by alternating electric currents.

Ordinary household power alternates at a frequency of 50-60 cycles per second (hertz). This backgrounder will be limited to discussion of these "power-frequency" or "extra-low frequency" EMFs, since they are a primary area of controversy or concern. Health concerns also exist over many other forms of electromagnetic energy -- from microwaves and cell phones to radio towers and radar. But the much higher-energy fields created by these higher-frequency currents are quite different in terms of physics and biology, and they must be evaluated separately.

Why Cover EMFs?

EMFs are worth covering because anything that could affect people’s health is worth covering. Moreover, it is almost impossible for anyone in the modern industrial world to avoid some exposure to them. People have a right to the best information -- although sorting it out is not always easy. It is important because it affects people’s peace of mind.

Story Ideas

1. What are the findings and conclusions of the major reviews of research on the health effects of EMFs?

2. Are there high-voltage power distribution lines in your community? Has anyone measured the fields that they generate? How far are the lines from residential areas and other populated places?

3. What, if any, provisions are there in your local building code for minimizing generation of EMFs by home wiring?

4. What steps can ordinary people take to minimize their exposure to EMFs?

5. Do any industrial facilities in your area expose workers to EMF levels much higher than those a person in an ordinary residence would be exposed to?

6. What new studies on EMFs and health are being reported? Have they been published in peer-reviewed scientific journals? How do they square with other research?

Issues

- Could confounding factors account for the weak association between EMFs and childhood leukemia and chronic lymphocytic leukemia? What might they be? (E.g., age of housing, income level, ....)

- Are ratepayers and consumers willing to pay for the extra degree of protection from EMF exposure which the electrical industry could achieve?

- Does the lack of conclusive evidence that power-frequency EMFs cause cancer mean that other mechanisms of EMF exposure (microwaves, radar, cell phones, etc.) also deserve a clean bill of health?

- What physical and biological mechanisms could account for the weak epidemiological association betweem EMF exposure and childhood leukemia?

- What further research could help resolve uncertainties?

- Should the government set limits for occupational exposure to EMFs, which can be much higher than residential exposures?

Background and Context

Concern was sparked by a 1979 article published in the American Journal of Epidemiology by researchers Nancy Wertheimer and Ed Leeper. Using the type of powerlines as an index of exposure, they found higher exposures associated with an excess incidence of childhood leukemia and brain cancer.

That study and the suspicions it aroused inspired scores of additional scientific studies, as well as journalistic "exposes" such as Brodeur’s. Yet after two decades, little evidence has been found to support the suspicions.

In the 1992 Energy Policy Act Congress called for a review of the science on EMFs. Reviews under that mandate were published by the National Research Council (affiliated with the National Academy of Sciences) in 1996 and the NIEHS in 1999.

While not giving EMFs a clean bill of health, the reviews concluded that there was little strong evidence that EMFs were causing harm to human health in normal circumstances.

For one thing, lab studies could not show genetic damage or cancer in cells or test animals exposed to many times the level of EMFs most people are exposed to. Nor did the studies come up with other plausible mechanisms by which EMFs could be causing problems.

And although early studies, such as those by Wertheimer and Leeper, showed a statistical association between EMF exposure and certain cancers, other studies, larger and more rigorous, could not replicate those results.

The minority of studies that did show some association failed to find any dose-response relationship. When theoretical indexes of exposure (based on types of wiring) were replaced with actual measurements of fields, the association vanished.

There was some evidence that workers in electrical occupations (linemen or welders) who received much higher exposures were having higher rates of some cancers.

There is much people can do to reduce their own exposure if they are still worried about EMFs despite lack of scientific demonstration that they cause significant harm. Except in certain cases, most people’s greatest exposure to EMFs may come from sources inside the home, rather than from power lines outside it. It is worth remembering that intensity of EMFs decreases proportionally to the square of the distance to their source. So doubling the distance between you and an electric motor will reduce your exposure to one-quarter of its previous level.

The NIEHS suggests avoiding standing too close to computers, microwave ovens, televisions, or other devices that may emit EMFs. People can reduce the time of exposure to EMFs by turning off devices such as electric blankets when they are not in use. It may also be wise to avoid keeping devices such as electric alarm clocks too close to the bed. Adults can discourage children from playing near high power lines or electrical transformers.

Research Findings

National Research Council "...the conclusion of the committee is that the current body of evidence does not show that exposure to these fields presents a human-health hazard. Specifically, no conclusive and consistent evidence shows that exposures to residential electric and magnetic fields produce cancer, adverse neurobehavioral effects, or reproductive and developmental effects."

National Institute of Environmental Health Sciences "The NIEHS believes that the probability that EMF exposure is truly a health hazard is currently small. The weak epidemiological associations and lack of any laboratory support for these associations provide only marginal scientific support that exposure to this agent is causing any degree of harm."

Sources and Resources

- National Research Council, Commission on Life Sciences, Board on Radiation Effects Research, Committee on Possible Effects of Electromagnetic Fields on Biologic Systems, Possible Health Effects of Exposure to Residential Electric and Magnetic Fields (1997). http://www.nap.edu/books/0309054478/html/index.html

- National Institute of Environmental Health Sciences, NIEHS REPORT on Health Effects from Exposure to Power-Line Frequency Electric and Magnetic Fields. NIH Publication No. 99-4493, May 4, 1999, http://www.niehs.nih.gov/emfrapid/html/EMF_DIR_RPT/Report_18f.htm NIEHS CONTACTS: Bill Grigg , (301) 402-3378 or Tom Hawkins, (919) 541-1402

- Paul Brodeur, Currents of Death: Power Lines, Computer Terminals, and the Attempt to Cover Up Their Threat to Your Health, Simon & Schuster, NY, 1989. Brodeur, Paul.: The great power-line cover-up- how the utilities and the government are trying to hide the cancer hazard posed by electromagnet; Boston: Little, Brown and Co., 1993.

- John E. Moulder, Ph.D., professor of radiation oncology, Medical College of Wisconsin, Powerlines and Cancer FAQs http://www.mcw.edu/gcrc/cop/powerlines-cancer-FAQ/QandA.html, jmoulder@its.mcw.edu. A fairly objective and detailed discussion of the science questions and findings related to EMFs and human health, in Frequently Asked Questions (FAQ) form. Includes citations of many major scientific studies.

- Sustainable Building Sourcebook, Sustainable Sources Online, http://www.greenbuilder.com/sourcebook/Emf.html.

- National Library of Medicine, Medline Plus, Electromagnetic Fields. http://www.nlm.nih.gov/medlineplus/electromagneticfields.html.

- NIOSH Fact Sheet: EMFs In The Workplace, http://www.cdc.gov/niosh/emf2.html.

Reprinted with permission. Published in Environment Writer newsletter February 2000, by the National Safety Council's Environmental Health Center.