Extremely-low-frequency Electromagnetic Fields--WHO classifies the cancer risk.


In 1996, the World Health Organization (WHO) established the International Electromagnetic Fields (EMF) Project to address the health issues associated with exposure to EMF. The EMF Project is currently reviewing research results and conducting risk assessments for exposure to static and extremely-low-frequency (ELF) electric and magnetic fields. WHO plans to conduct an evaluation of all health effects from ELF field exposure in 2002-2003.

Whenever electricity is conducted through transmission lines, is transported through distribution lines, or is used in appliances, both electric and magnetic fields exist close to the lines or appliances. The power frequency used is 50 or 60 Hz. Use of electric power has become part of everyday life. Questions have been raised, however, as to whether these and other ELF fields are carcinogenic.

The International al Agency for Research on Cancer (IARC)--a specialized Cancer research agency of WHO--has recently concluded a first step in WHO's health risk assessment process by classifying ELF fields with respect to the "strength of the evidence" that they could cause cancer in humans.

IARC Evaluation

In June 2001, an expert scientific working group of IARC reviewed studies related to he carcinogenicity of static and ELF electric and magnetic fields. Using the standard IARC classification that weighs human, animal, and laboratory evidence, the researchers classified ELF magnetic fields as possibly carcinogenic to humans based on epidemiological studies of childhood leukemia. Evidence for all other cancers in children and adults, as well as for other types of exposure (i.e., static fields and ELF electric fields) was considered not classifiable because of either insufficient or inconsistent scientific information.

"Possibly carcinogenic to humans" is a classification used to denote an agent for which there is limited evidence of carcinogenicity in humans and less-than-sufficient evidence for carcinogenicity in experimental animals. This classification is the weakest of three categories ("carcinogenic to humans," "probably carcinogenic to humans," and "possibly carcinogenic to humans") used by IARC to classify potential carcinogens according to published scientific evidence.

Do ELF Fields Cause Cancer?

ELF fields are known to interact with tissues by inducing electric fields and currents in them. This is the only established mechanism of action of these fields. The electric currents induced by ELF fields...

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