The World Health Organization (WHO) concluded a review of the potential health implications of extremely low frequency (ELF) EMF, which includes power-frequency fields. Its conclusions and recommendations were presented in June 2007 in a report known as the Extremely Low Frequency Fields, Environmental Health Criteria Monograph No. 238.
The WHO report concluded that evidence for a link between ELF magnetic fields and childhood leukemia "is not strong enough to be considered causal but sufficiently strong to remain a concern." "Virtually all of the laboratory evidence and the mechanistic evidence fail to support" this reported association. For all other diseases, there is inadequate or no evidence of health effects at low exposure levels.
The report emphasized that, given the weakness of the evidence for health effects, the health benefits of exposure reduction are unclear and policies based on the adoption of arbitrary low exposure limits are not warranted.
In light of this situation, WHO made these and other recommendations:
In June 1999, the federal government completed a $60 million extremely low frequency, ELF, electric and magnetic field, EMF, research program managed by the National Institute of Environmental Health Sciences, NIEHS, and the Department of Energy, DOE. This program is known as the EMF Research And Public Information Dissemination, RAPID, Program. In its report to Congress, the NIEHS concluded:
The NIEHS believes the probability that ELF-EMF exposure is a genuine 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 causes any degree of harm.
The NIEHS report also included the following conclusions:
It is our opinion that based on evidence to date, ELF-EMF exposure would not be listed in the "Report on Carcinogens" as an agent "reasonably anticipated to be a human carcinogen."
The NIEHS agrees that the associations reported for childhood leukemia and adult chronic lymphocytic leukemia cannot be dismissed easily as random or negative findings. The lack of positive findings in animals or in mechanistic studies weakens the belief that this association is actually due to ELF-EMF, but cannot completely discount the finding. The NIEHS also agrees with the conclusion that no other cancers or non-cancer health outcomes provide sufficient evidence of a risk to warrant concern.
Virtually all of the laboratory evidence in animals and humans, and most of the mechanistic work done in cells, fail to support a causal relationship between exposure to ELF-EMF at environmental levels and changes in biological function or disease status.
... the evidence suggests passive measures such as a continued emphasis on educating both the public and the regulated community on means aimed at reducing exposures are beneficial. NIEHS suggests that the power industry continue its current practice of siting power lines to reduce exposures and continue to explore ways to reduce the creation of magnetic fields around transmission and distribution lines without creating new hazards.
For information about the NIEHS EMF RAPID Program, or to obtain copies of its report, visit the EMF RAPID Program home page.
In May 1999, the National Research Council/ National Academy of Sciences, an independent scientific agency responsible for advising the federal government on science, technology, and medicine, released its evaluation of the scientific and technical content of research projects conducted under the U.S. EMF RAPID Program. It concluded that:
The results of the EMF-RAPID program do not support the contention that the use of electricity poses a major unrecognized public-health danger. Basic research on the effects of power-frequency magnetic fields on cells and animals should continue but a special research funding effort is not required. Investigators should compete for funding through traditional research-funding mechanisms. If future research on this subject is funded through such mechanisms, it should be limited to tests of well-defined mechanistic hypotheses or replications of reported positive effects. If carefully performed, such experiments will have value even if their results are negative. Special efforts should be made to communicate the conclusions of this effort to the general public....
For copies of the NRC/NAS report visit the National Academy Press web page.
In August 2004 the California Public Utilities Commission (CPUC) began a proceeding known as a "rulemaking" (R.04-08-020) to explore whether changes should be made to existing CPUC policies and rules concerning EMF from electric transmission lines and other utility facilities.
Through a series of hearings and conferences, the CPUC evaluated the results of its existing EMF mitigation policies and addressed possible improvements in implementation of these policies. The CPUC also explored whether new policies are warranted in light of recent scientific findings on the possible health effects of EMF exposure.
The CPUC completed the EMF rulemaking in January 2006 and presented these conclusions in Decision D.06-01-042:
NOTE: All of these policies have been implemented and are reviewed as new information becomes available.