December 2008 Bill Inserts
Each month, PG&E offers important information on rebates, saving energy and safety in printed inserts that accompany your bill. Now, access this information online whenever you wish.
|PG&E is getting prepared for the winter storm season—and so should you.|
For safety tips and helpful information.
Understanding Electric and Magnetic Fields (EMF): What they are as well as information and health studies.
Understanding Electric and Magnetic Fields (EMF)
Questions have been raised about the possible health effects of 60-Hertz (power frequency) electric and magnetic fields (EMF), which are found wherever you have electric power. This notification contains information that will help you understand the EMF issue, plus practical tips you can use if you want to reduce your exposure at home and at work.
Campos Eléctricos y Magnéticos (EMF): Si desea recibir información en español, comuníquese con Pacific Gas and Electric Company al 1-800-660-6789.
Can EMF harm your health?
Electric and magnetic fields are present wherever electricity flows—around appliances and power lines, and in offices, schools and homes. Many researchers believe that if there is a risk of adverse health effects from usual residential exposures to EMF, it is probably just at the detection limit of human health studies; nonetheless, the possible risk warrants further investigation. The varying results from epidemiological studies, which looked at estimated EMF exposures and childhood leukemia, are consistent with a weak link. Laboratory studies and studies investigating a possible mechanism for health effects (mechanistic studies) provide little or no evidence to support this weak link.
The results from many research studies have been evaluated by international, national and California EMF research programs to find out if EMF poses any health risk. Given the uncertainty of the issue, the medical and scientific communities have been unable to determine that usual residential exposures to EMF cause health effects or to establish any standard or level of residential exposure that is known to be either safe or harmful. These conclusions remain unchanged by recent studies.
World health organization findings
The World Health Organization (WHO) recently concluded a review of the potential health implications of extremely low frequency (ELF) EMF, which includes power-frequency fields. Their conclusions and recommendations were presented in June 2007 in a report known as the Extremely Low Frequency Fields, Enviromental 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.
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:
- National authorities should implement communication programs with all stakeholders to enable informed decision-making, including how individuals can reduce their own exposure.
- Policy makers and community planners should implement very low-cost measures to reduce exposures when constructing new facilities and designing new equipment, including appliances.
- Policy makers should use existing international guidelines (833 and 9,000 milligauss) to establish standards for exposure to short-term, high-level ELF fields. These guidelines pertain to field levels that are virtually never encountered by the general public except from a few electric appliances.
- Government and industry should promote research to reduce the uncertainty of the scientific evidence on the health effects of ELF field exposure. Several recommended research projects are already under way through the Electric Power Research Institute, of which PG&E is a member.
To view the full report and a fact sheet summarizing it, visit:
Magnetic Fields at Home
(Measurements are in milligauss)
|1.2" away||12" away||39" away|
|Microwave Oven||750 to 2,000||40 to 80||3 to 8|
|Clothes Washer||8 to 400||2 to 30||0.1 to 2|
|Electric Range||60 to 2,000||4 to 40||0.1 to 1|
|Fluorescent Lamp||400 to 4,000||5 to 20||0.1 to 3|
|Hair Dryer||60 to 20,000||1 to 70||0.1 to 3|
|Television||25 to 500||0.4 to 20||0.1 to 2|
|Source: Adapted from Gauger 1985.|
Magnetic Fields Outside
(Maximum values may be lower for some California utilities)
|Distribution Lines||1 to 80 milligauss under the line|
|Transmission Lines||1 to 300 milligauss edge of right-of-way|
What you can do
In a situation of scientific uncertainty and public concern, WHO recommended that utilities explore “very low-cost” ways to reduce EMF exposure from new or upgraded facilities. PG&E and other California public utilities already pursue no-cost and low-cost measures to reduce EMF levels from new utility transmission lines and substation projects. You, too, may want to take no-cost and low-cost measures to reduce your EMF exposure at home and at work.
Human studies have not produced a consensus about any health benefits from changing the way people use electric appliances. But, if you feel reducing your EMF exposure would be beneficial, you can increase your distance from electric appliances and/or limit the amount of time you use appliances at home or at work. For instance, you can place phone answering machines and electric clocks away from the head of your bed. Increasing your distance from these and other appliances such as televisions, computer monitors and microwave ovens can reduce your EMF exposure.
You can also reduce your EMF exposure by limiting the time you spend using personal appliances such as hair dryers, electric razors, heating pads and electric blankets. You may also want to limit the time you spend using electric cooking appliances.
You can locate the sources of EMF in your work environment, and spend break time in lower-field areas.
It is not known whether such actions will have any impact on your health.
For More Information
Call Pacific Gas and Electric Company for a free information package or home or business measurements at 1-800-PGE-5000.