Understanding Electromagnetic Fields
An electromagnetic field, sometimes referred to as EMF, is created by electrical charges and currents flowing though wires. When an appliance is turned on, current or charge flows creating EMF. Given the widespread use of electricity, electromagnetic fields or EMFs are present everywhere in our daily lives.
Safety practices and EMF exposure
Extensive research on EMF exposure and safety has been conducted by international and national scientists. The results from this research have been evaluated by reputable international and national scientific and public health organizations and agencies. Oregon Trail Electric Cooperative relies on the evaluations from these organizations and agencies when assessing potential risks. All of OTEC’s facilities, transmission and distribution lines follow the rules, regulations and standards for electromagnetic field exposure to provide safe and reliable electric service.
Electric and magnetic field (EMF) exposure
EMFs occur anywhere there is electric power. Most electromagnetic fields found in homes are power frequency (60-hertz), which is categorized as extremely low frequency (ELF). Common sources of electric and magnetic fields in the home are appliances, televisions, computers, and standard electrical wiring. Anything that has a voltage has an ELF electric field. When a device is turned on, electrical current flows, which also creates an ELF magnetic field.
The electric fields near outdoor transmission lines are typically stronger than those found in homes because they have a higher voltage than residential sources or appliances/devices. On the other hand, the magnetic fields around electrical appliances in homes can be as high as or higher than the magnetic fields near outdoor power lines. Because electromagnetic fields decrease significantly with distance from the source, EMF exposure from power lines is reduced significantly by the distance from the wires – including the height of the towers or poles that carry overhead transmission and distribution lines. Transmission line electric fields, but not magnetic fields, are also shielded by trees and homes, so that they are further reduced inside homes and buildings.
The chart below illustrates how the magnetic field exposure lessens with an increase in distance from typical electric sources at home.
Measurements are in milligauss:
What can you do?
In a situation of scientific uncertainty and public concern, the World Health Organization recommended that utilities explore “very low-cost” ways to reduce EMF exposure from new or upgraded facilities. OTEC and other 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.
World Health Organization Findings
The World Health Organization (WHO) completed a review of the potential health implications of extremely low frequency 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, 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 adopting policies based on the arbitrary low exposure limits are not warranted.