Understand Electromagnetic Fields (EMF)
Explore potential EMF health effects
Wherever there is power, a 60 hertz (Hz) (cycles per second) EMF is present. This page provides information about EMF and its effect on your health.
View 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. Visit 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.
Learn what the United States is doing about EMF and ELF
Many government agencies conduct reports about EMF health effects.
Discover the EMF findings of the National Institute of Environmental Health Sciences (NIEHS) and the Department of Energy (DOE)
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. Visit Electric & Magnetic Fields.
Discover the EMF findings of the National Research Council (NRC) and the National Academy of Sciences (NAS)
NRC and NAS analyzed the EMF 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....”
The National Academies Press website has copies of the NRC/NAS report. Visit National Academies Press.
Discover 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 CPUIC:
- 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.
Find out 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.
View the results of the study. Visit EMF Frequently Asked Questions page, and then viewing the American Pre-Apprentice/Utility Worker Study section.
Learn PG&E EMF policies
PG&E has a separate, 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.
PLEASE NOTE: PG&E implemented all of these policies. We review them as new information becomes available.