AC Fields - Health Concerns

A review of current research literature regarding exposure to AC magnetic fields and human health risks, would likely reveal the following:

The most recent reviews of the available scientific literature by independent panels of scientific experts are consistent in concluding that:

1. Low-level (e.g., under about 10 Gauss) EMF exposures to AC magnetic fields have not been established as a health hazard, but that
2. The possibility cannot be ruled out for a relationship with some diseases, including childhood leukemia.

Two of the most authoritative expert panels are the World Health Organization International Agency for Research on Cancer (IARC) and the United Kingdom National Radiological Protection Board (UK NRPB).

IARC, UK NRPB and all other 'expert panel' reports (e.g., US National Institute of Environmental Health Sciences "EMF RAPID" <1999>; ICNIRP Standing Committee on Epidemiology <2001>; California Department of Health Services <2002>) have concluded that EMF exposure has not been established as a cause of disease. Importantly, however, all of these panels have also concluded that research on these exposures should continue and, in a departure from the usual form on such work, all three California Department of Health Services principal scientists stated that they "are inclined to believe that EMFs can cause some degree of increased risk of childhood leukemia, adult brain cancer, Lou Gehrig's Disease, and miscarriage".

IARC concluded that magnetic field exposure is "possibly carcinogenic" for childhood leukemia (IARC, 2001). The evidence for all other cancers (e.g., brain cancer in both children and adults) and occupational exposures was determined to be "inadequate," leading to the "Not classifiable as to carcinogenicity" (IARC Group 3).

The U.S. National Institute of Environmental Health Sciences (NIEHS, 1999) Director concluded that:

"The scientific evidence suggesting that [EMF] exposures pose any health risk is weak ...[but they] cannot be recognized at this time as entirely safe because of weak scientific evidence that exposures may pose a weak leukemia hazard."

In Britain, the NRPB arrived at a similar conclusion:

"After a wide-ranging and thorough review of scientific research, an independent Advisory Group to the Board of NRPB has concluded that the power frequency electromagnetic fields that exist in the vast majority of homes are not a cause of cancer in general. However, some epidemiological studies do indicate a possible small risk of childhood leukemia associated with exposure to unusually high levels of power frequency magnetic fields."

IARC is the first health authority to clearly designate power-frequency magnetic fields as "possibly carcinogenic". It is important to acknowledge that the IARC assessment is based on rather specific "criteria" that resulted in the categorization of the epidemiological evidence as "limited" and the animal bioassay data as "inadequate." The IARC criteria describe "Limited" epidemiological evidence as: "A causal relationship is credible, but chance, bias, or confounding could not be ruled out with reasonable confidence…" If it were not for the desire to be cautious in the face of a "limited" finding in the epidemiology, the largely negative results from biophysics, laboratory experiments, and studies of rats and mice would be sufficient to conclude that a health hazard is very unlikely to result from EMF exposures.

Clearly there is ample room and reason for further.

Given the controversy, FMS sees three policy options with respect to existing or new facilities.

1. It is possible to conclude that there is no need to take any action, in as much as a long-term research effort has failed to firmly establish a risk from low-level EMF exposure.
2. Reliance on 'Science-based numeric exposure standards' which, except for the most unusual circumstances, will not demand action.
3. Reliance on a combination of the 'Science-based numeric standards' and an interim policy of 'precaution' in response to the uncertainty associated with future research results.

The third option allows limited and measured responses to existing or future elevated fields. For example, if a building is being designed and the most efficient location for high-current electrical facilities will cause significantly elevated AC magnetic fields where people with electrical/electronic equipment will work, it may be prudent to install shielding during the construction phase in order to lower the risk to both human health and equipment interference. The same might be true for tenant improvement projects, assuming that the costs are reasonable.

In the end, the customer with an existing or potential EMF problem with elevated AC magnetic field levels, need to make a difficult decision. If the problem includes anxiety about health risks, FMS strongly advise the customer to become their own expert, since there is, as yet, no definitive answer to the question of what is "safe" and what is "harmful". For those interested in learning more, please see Page titled "EMF Health Concern Resource Links" on this site.