Considering the media interest in mis-reporting
the NCI Study, what was surprisingly NOT reported in
the Australian media was the release of a large
Swedish EMF human exposure study less than three
weeks before the NCI study. The Swedish study
included approximately 400,000 subjects who had lived
within 300 meters of transmission lines in Sweden for
at least one year between 1960 and 1985. The
researchers found that persons who were exposed to
magnetic fields both at home and at work are nearly 4
times likely to develop leukemia than those who were
not exposed to magnetic fields.
To quote from the Epidemiology Press
Release of 16 June 1997:
"Dr Maria Feychting and colleagues at the
Karolinska Institute and the National Institute for
Working Life in Sweden report in the July issue of
Epidemiology that persons who were exposed to
magnetic fields both at home and at work are nearly 4
times likely to develop leukemia as those were not
exposed to magnetic fields.
Dr. Feychting and colleagues conducted a
case-control study from among approximately 400, 000
subjects who had lived within 300 meters of
transmission lines in Sweden for at least one year
between 1960 and 1985. The investigators designated
as cases 325 residents diagnosed with leuk-emia and
223 residents diagnosed with a tumor of the central
nervous system. For each case identified, they
selected at random at least two control subjects of
the same sex and five-year age group who had lived in
the same parish as the case.
They assessed exposure to magnetic fields
generated by transmission and distribution power
lines close to each subject's house, excluding buried
power cables from the calculations. They obtained
information on each subject's occupation from
five-year censuses. They assessed occupational
magnetic field exposures for each subject through
extrapolation of exposure estimates for each
occupation and without knowledge of wether the
subject was a case or control. The investigators took
into account in their analysis other occupational
exposures, such as benzines, oil products, solvents,
and welding fumes, that have been associated with
leukemia in earlier studies. They compare the
residential and occupational histories of the cases
with the histories of controls.
Subjects in the highest category of occupational
exposure to magnetic fields (0.20 microT,or 2 mG) had
nearly double the risk of developing acute myeloid
leukemia, a 40% increase in risk of developing
chronic myeloid leukemia, and a 70% increase in risk
for chronic lymphocytic leukemia when compared with
unexposed subjects. Those with high levels of
exposure to magnetic fields at home had double risk
of developing acute myeloid leukemia and chronic
myeloid leukemia as those who were unexposed.
Among subjects who had high exposures to magnetic
fields at home and at work, the risk of developing
acute myeloid leukemia and chronic myeloid leukemia
increased more than 6 fold and doubled for chronic
lymphocytic leukemia when compared with subjects who
had not been exposed to magnetic fields. Results for
central nervous system tumors were consistent with no
increase in risk."
(Feychting M., et al , Occupational and
residential magnetic field exposure and leukemia and
central nervous system tumors. Epidemiology 1997; 8;
384-389 )
