Urgent Alert

Electric and Magnetic Fields (EMF)

Explore potential EMF health effects

Wherever there is electricity, EMF is present. This page provides information about power frequency, 60 hertz (Hz) (cycles per second) EMF and its effect on your health.

EMF findings

World Health Organization (WHO) Extremely Low Frequency (ELF) EMF findings


The WHO reviewed the potential health effects of ELF EMF, which includes power-frequency fields. The WHO reported its findings in a June 2007 report, "Extremely Low Frequency Fields, Environmental Health Criteria Monograph No. 238." The report explored the potential link between ELF EMF and childhood leukemia. The WHO concluded that the link is not strong enough to consider ELF EMF a cause. The association with other diseases and ELF EMF also isn’t proven.


The lack of evidence on negative health effects doesn’t mean that ELF EMF offers health benefits. Given the weak evidence of health effects, the health benefits of exposure reduction are unclear. Therefore, policies of adopting arbitrary low ELF EMF exposure limits are unnecessary. With this in mind, WHO recommends:

  • National authorities need to create communication programs. These programs support stakeholder decision-making. The purpose includes informing you on how you can reduce your exposure.
  • Policymakers and community planners can implement low-cost measures to reduce exposure. These measures apply to new facility construction and new equipment design, including appliances.
  • Policymakers can use international guidelines to establish exposure limits for short-term, high-level ELF fields. The current recommended limit is 833 to 9,000 milligauss. These guidelines apply to ELF sources that the general public rarely encounters.
  • Governments and industries need to promote more research on the health effects of ELF fields. Several research projects are underway with the Electric Power Research Institute. PG&E is a member of this institute.

Read the full report: Extremely Low Frequency Fields Environmental Health Criteria Monograph No.238.


You can also view a quick fact sheet. Visit Electromagnetic fields (EMF) Fact sheets and backgrounders.

National Institute of Environmental Health Sciences (NIEHS) and Department of Energy (DOE) EMF Findings


The federal government completed a $60 million research program in June 1999. This program studied EMF and ELF. The NIEHS and the DOE managed the study. The program is known as the EMF Research and Public Information Dissemination (RAPID) Program.


Following are NIEHS conclusions provided in a report to congress:


"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 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."


View more information about EMF on the NIEHS website.

National Research Council (NRC) and National Academy of Sciences (NAS) findings


NRC and NAS analyzed the EMF Research and Public Information Dissemination (RAPID) program. The agencies ran a study of the scientific and technical content projects in the program that concluded:


"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..."


Visit National Academies Press for copies of the NRC/NAS report.

California EMF policies

The California Public Utilities Commission (CPUC) met in August 2014. This meeting is known as "rulemaking." The CPUC explored whether policies regarding EMF needed to be changed. The commission also explored the need for new policies. The CPUC completed the EMF rulemaking in January 2006.


Following are conclusions reached by the CPUC:

  • Confirmation of measures for utility transmission lines and substation projects. These no-cost and low-cost methods are designed to reduce EMF levels.
  • Adoption of rules and policies to improve utility design guidelines for reducing EMF. The policies also called for a workshop. The workshop's focus was to implement the policies and standardize design guidelines.
  • Verification of the inability to link EMF to negative health effects. The findings came from California Department of Health Services (DHS) studies.
  • A plan to stay vigilant about new EMF studies. The CPUC will reconsider EMF policies and pursue new rulemaking upon discovering negative health impacts.

How PG&E supports EMF research

PG&E supports and funds medical, scientific and industry EMF research. We plan to continue these efforts. PG&E employees participated in an EMF occupational study. This study was done with four other utilities. It gathered the medical records of nearly 139,000 workers. The purpose of this study was to verify or disprove a link between EMF and brain cancer or leukemia.

See the FAQ, "What are the findings of the American pre-apprentice and utility worker study" below to view the results of the study.


PG&E EMF policies


PG&E has a written policy for EMF. We have maintained this policy since 1987. PG&E aims to:

  • Create procedures to consider EMF exposure. The procedures are used in the designs of new and upgraded facilities.
  • Take steps to reduce EMF exposure. Steps include reasonable measures to reduce EMF exposure in the design of new and upgraded facilities.
  • Encourage an effort to address public concern about EMF exposure. This effort covers multiple industries. Another goal is to increase energy efficiency.
  • Work closely with employees to improve EMF policies. PG&E works with employees and union leadership. We coordinate with both groups to review and implement EMF policies.
  • Give customers up-to-date EMF information. We can also conduct EMF measurements upon request.
  • Fund and participate in EMF research. PG&E works closely with government officials to resolve EMF issues.
  • Perform EMF measurements. PG&E provides free EMF measurements to customers who have concerns about EMF.  Call 1-877-660-6789 to request a free measurement.


important notice icon Note: PG&E implemented all these policies. We review them as new information becomes available.

Frequently asked questions

EMF are invisible force fields. These fields come from electric voltage, also known as electric fields, and by electric current, also known as magnetic fields. Electromagnetic fields occur where a flow of energy is present.

The California Public Utilities Commission (CPUC) and the California Department of Health Services (DHS) have not concluded that exposure to magnetic fields from utility electric facilities poses health risks. PG&E relies on information from federal and state health agencies that conduct EMF research and monitor this issue to help evaluate potential risks.

The U.S. has no health-related standards for long-term exposure to EMF. Government agencies can’t create these standards, because there are no reported adverse health effects.

Many groups have created reports about EMF. The reports found no direct evidence of EMF producing adverse health effects. The reports also agreed that more research is needed to answer the health question.

Studies include:

  • Possible Health Effects of Exposure to Residential Electric and Magnetic Fields, National Research Council, United States, October 1996.
  • Effects of Electric and Magnetic Fields, Report of the Council on Scientific Affairs to the American Medical Association, United States, December 1994.
  • Electromagnetic Field Exposure and Cancer: A Review of Epidemiological Evidence, American Cancer Society, United States, January/February 1996.

Power Line Fields and Public Health, Council of the American Physical Society, United States, May 1995.

Five Swedish agencies published an EMF guidance document: Low-Frequency Electrical and Magnetic Fields: The Precautionary Principle for National Authorities — Guidance for Decision-Makers. The document was published in September 1996. The five agencies recommend:

"If measures to reduce exposure can be taken at reasonable expense and with reasonable consequences in all other aspects, an effort should be made to reduce fields radically deviating from what could be deemed normal in the environment. Where new electrical installations and buildings are concerned, efforts should be made ... at the planning stage to design and position them in such way that exposure will be limited."

The document states that limits on EMF exposure are not needed. The lack of limits is based on the scientific information available to date.

Many studies of EMF exposure for utility workers explore the potential link between employee health and EMF.

Dr. Jack Sahl at Southern California Edison Company studied 38,000 electric utility workers. The study reported:

"We found no consistent association between either work in electrical occupations or magnetic fields measured in the work environment and death from all combined cancers, leukemias, brain cancers, or lymphomas..."

Dr. Gilles Theriault studied the possibility of elevated cancer risk for French and Canadian utility workers. The study analyzed 230,000 individuals. The results of this study are similar to other EMF research results: cancer risk doesn’t appear to be linked with EMF exposure.

Dr. David Savitz and Dr. Dana Loomis studied the link between EMF and diseases like brain cancer and leukemia. The doctors studied 139,000 American pre-apprentice and utility workers. The study results include the following statements:

"This study is a major new contribution and simultaneously provides evidence against an association with leukemia and for an association between magnetic fields and brain cancer. It does not, however, resolve the fundamental question of whether magnetic fields cause cancer.

Reasons for inconsistencies between this study and previous investigations of electric pre-apprentice/utility workers in Canada and France and at the Southern California Edison Company are not clear, but will be examined more thoroughly. Possible explanations are the different approaches to exposure assessment and methods of identifying and classifying cancers."

Additional resources

Electric and magnetic fields: NIH

Read National Institute of Environmental Health Sciences (NIH) information about EMFs.

Electromagnetic fields: WHO

Learn about the World Health Organization (WHO) International EMF Project and more.

EMF consultants: EMDEX

Find meter sales and calibration services, plus measurement and computer modeling services.