This update summarizes the conclusions and recommendations presented in the NIEHS report released in June 1999. Potential implications of these findings for the utility industry are briefly discussed.
The NIEHS report describes the activities of the EMF RAPID Program, including the Working Group. It supercedes the assessment of the Working Group and provides an updated assessment of the epidemiological and laboratory studies. The report concludes that “The NIEHS believes that the probability that ELF-EMF exposure is truly a health hazard is currently small.” NIEHS further suggests that the power industry continue current practices, such as educating the public, and siting and designing power lines to reduce magnetic fields. These practices were described in their 1995 brochure, “Questions and Answers About EMF,” prepared with the U.S. Department of Energy.
The Conclusions of the NIEHS Are Expressed in Several Different Ways
Application of Formal Criteria
The report acknowledges the conclusions reached by the application of formal criteria for cancer risk assessment used by the International Agency for Research on Cancer (IARC) and the National Toxicology Program (NTP) in the U.S., but provides its own independent assessment.
- Using the IARC criteria — NIEHS notes that none of the Working Group considered the evidence strong enough to label ELF-EMF a “known human carcinogen” or “probable human carcinogen.”
- Using the NTP approach — The NIEHS opinion is that ELF-EMF exposure would not be listed in the NTP Report on Carcinogens as a “known human carcinogen” or as “reasonably anticipated to be a human carcinogen.”
- The NIEHS assessment — The level and strength of evidence supporting ELF-EMF exposure as a human health hazard are insufficient to warrant aggressive regulatory actions.
Strength of the Evidence
- The scientific evidence suggesting that ELF-EMF exposure poses any health risk is weak.
- The weak epidemiological associations and lack of any laboratory support for these associations [childhood leukemia and adult] provide only marginal, scientific support that exposure to this agent is causing any degree of harm. The NIEHS press release that accompanied the report characterized the report as recommending “that the 1
fields continue to be recognized as a “possible” cancer hazard [similar to the Working Group’s application of the
IARC category rating of “possible human carcinogen”].” However, no text to support this statement can be found
in the report. The NIEHS report does note the previous assessment of the Working Group, but for its own
conclusion merely “agrees that the associations reported for childhood leukemia and adult chronic lymphocytic
leukemia cannot be dismissed easily as random or negative findings.” This conclusion is consistent with the recent assessment that “The results of the EMF-RAPID program 2 do not support the contention that the use of electricity poses a major unrecognized public-health danger.”(National Academy of Sciences, Final Report of the Committee to Review the Research Activities Completed Under the Energy Policy Act of 1992, 1999).
- The level of epidemiological evidence [for childhood leukemia], while weak, is still sufficient to warrant limited concern.
- No other cancers or non-cancer health outcomes provide sufficient evidence of a risk to warrant concern.
- Laboratory data in animal models provide no support for the reported epidemiological findings of increased risk of leukemia.
- The findings of the lifetime [animal] bioassay study are consistent with the absence of an effect on leukemia/lymphoma.
- Laboratory evidence . . . fails to support a causal relationship between exposure to ELF-EMF at environmental levels and changes in biological function or disease status.
The NIEHS Conclusions
- “ELF-EMF exposure cannot be recognized as entirely safe because of weak evidence that exposure may pose a leukemia hazard.”1
- “The NIEHS believes that the probability that ELF-EMF exposure is truly a health hazard is currently small.”2
All but One of the Expressions of Conclusions of the Report Appear Informative and Useful for Communicating with the Public. The exception is the phrase “cannot be recognized as entirely safe.” This phrase is technically flawed, and potentially misleading. The term safe is often equated with zero risk of an adverse effect. Because the word ‘safe’ is misleading, it may lead to misinterpretation; people may
interpret the whole phrase to mean that ELF-EMF is unsafe, that a definite risk is associated with the most modest exposure levels, and the risk is associated with multiple diseases or health endpoints. Other flaws in the use of this term are:
- The phrase is not scientifically valid. There is no scientific means to demonstrate that any substance or agent that we are exposed to is ‘entirely safe.’ For this reason, the term safety is generally not used for characterizing potential health effects of long-term exposures.
- The phrase is not associated with specified exposure levels or exposure duration. Reductions in exposure are nearly always associated with reductions in risk or increases in safety. Thus, statements regarding safety without exposure information are incomplete or misleading.
- The phrase is unrealistic. No environmental exposure, no media such as air or water, and not all foods can be considered entirely safe. By this criterion, the presence of even trace levels of such things as auto or diesel exhaust in our air, or residual chemicals or microorganisms in drinking water, would render any exposure whatsoever as “not entirely safe.”
- The phrase is inconsistent with regulatory policy in the U.S. Regulatory standards for food, air, and drinking water do not provide assurances that exposures are “entirely safe.” Regulations for carcinogens, for example, may limit risk from exposure to one excess case in 100,000 persons.
NIEHS Recommendations
- The NIEHS did not recommend “active regulation” that might include rating ELF-EMF for carcinogenicity, imposing environmental standards, or requiring a program to bury all transmission and distribution lines.
- NIEHS recommended “passive measures” such as a continued emphasis on educating both the public and the regulated community on means aimed at reducing exposures. These measures were described as follows:
- Reduce creation of fields around transmission and distribution lines without creating new hazards.
- Exposure in individual residences is linked to improper grounding and improper wiring; these can be mitigated and exposures reduced.
- Manufacturers are encouraged to consider reductions in magnetic fields in home and office appliances at minimal cost.
Possible Implications for Electric Utilities
The NIEHS encouraged inexpensive and safe reductions in exposure and is endorsing current utility practices regarding design and siting of new transmission and distribution lines. The report says little regarding the action of individuals, except to name a few appliances that can produce high magnetic fields, and to describe the types of homes that tend to have higher fields. The report notes that most utilities do now provide home measurements. Absent substantial new information suggesting risks from ELF-EMF exposures, this report suggests no new policies or
regulations are needed to address public concerns about exposures.
This document was prepared for Edison Electric Institute
by Bailey Research Associates, Inc.
June 1999
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