Do Power Cables and Household Wiring Cause Cancer?
WebMD News Archive
Dec. 2, 1999 (Minneapolis) -- Power cables and household wiring pose no
increased risk of leukemia or other childhood cancers, according to British
epidemiologists who reported their findings in two separate studies in the Dec.
2 issue of the journal The Lancet. These findings are similar to those
of studies conducted in the U.S., even though they refute suggestions that have
been highly publicized in mainstream media.
In studies that took place in the United Kingdom (U.K.) and New Zealand, no
link was found between typical levels of electromagnetic radiation and
childhood cancer. This study provides no evidence that exposure to
electromagnetic fields (EMF) associated with the electricity supply in the U.K.
increases risks for a variety of cancers, write the authors of the U.K.
Childhood Cancer Study. These include various forms of childhood leukemia,
cancers of the brain and spinal cord, and other childhood cancers.
"Physicians and biomedical scientists have always had a problem with the
proposed association between electromagnetic fields and childhood cancer,
because there's no biologic mechanism," author Nick Day, PhD, tells WebMD.
He says that mainstream media coverage of smaller studies showing a link has
given rise to public concern that there may be a link between electromagnetic
fields and cancer. "Our study concurs with [others] showing that the normal
levels of exposure don't pose a risk." He is a professor of epidemiology at
Cambridge University in England.
In this study, researchers compared the records of over 3,800 pediatric
cases of cancer and over 7,600 healthy subjects. When children with mean EMF
exposures of more than 0.2 microteslas (mcT) were compared with those with mean
exposures of less than 0.1 mcT, there was no significant difference in the
number of cases of leukemia, brain tumors, or other forms of cancers.
Microteslas are units that measure electromagnetic field exposure.
The study conducted in New Zealand revealed similar results. "The
analyses of ... 113 matched pairs ... showed no association [of childhood
leukemia] with magnetic field exposure," write John D. Dockerty, PhD, and
colleagues, in a research letter about findings in New Zealand. Dockerty is a
Nuffield Medical Fellow at Oxford University in Oxford, England.
However, a commentary by a spokesperson of the World Health Organization
(WHO) cautions that these findings are not definitive. Michael R. Repacholi,
PhD, and Anders Ahlborn cite several weaknesses in both the U.K. and New
Zealand studies; these include the fact that ways that electromagnetic fields
could change transiently were not measured, and the low number of children with
high exposures. "This is not the fault of the researchers. ... People are
not exposed to high magnetic fields in ... countries using 240-volt power
supplies, compared to North Americans who use 110 volts," says Repacholi,
the coordinator of Occupational and Environmental Health at the World Health
Organization in Geneva.
The U.K. Childhood Cancer Study received approximately 30% of its funding
from the Electricity Association in the U.K. and British Nuclear Fuels. In the
study by Dockerty and colleagues, the Health Research Council of New Zealand
received funding from Transpower New Zealand, which was used to buy dosimeters
used to measure EMFs.