- Chronic health problems
and transmission lines - A Preliminary
Study
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- A New Zealand study presented at the 2nd.
World Conference on Electricity and
Magnetism in Biology & Medicine,
Bologna, Italy, in June 1997, found
significantly increased risks for asthma,
arthritis, type-11 diabetes and combined
chronic health problems in adults living
near transmission lines.
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- The study, titled: Chronic Health
Problems in Adults Living Near
High-Voltage Transmission Lines: Evidence
for a Dose-Response Relation with
Magnetic Field Exposure, was conducted by
Ivan L.Beale, Department of Psychology,
University of Auckland, Roger J. Booth,
Department of Molecular Medicine,
University of Auckland, and Neil E.
Pearce, Wellington Asthma Research Group,
Wellington Medical School.
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- As part of a larger cross-sectional
study, in Auckland, New Zealand, 560
adults living near 50-Hz 110 kV
transmission lines completed
questionnaires about their residential
location and existing health problems.
-
- Magnetic field measurements were taken to
provide an estimate of each participant's
magnetic field exposure. Participants
were then divided into five groups of
112, based on their exposure. Summary
statistics for health status were
calculated for each group and the groups
were then compared for evidence of a
linear relation between health variables
and magnetic field exposure.
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- Significant linear dose-response patterns
were found for self-rated overall health,
asthma, rheumatoid arthritis, type-11
diabetes and all chronic health problems
combined, but not for infections or
allergies. Estimates of relative risk
were calculated for each health variable,
adjusted for the influence of possible
confounders such as age, gender,
ethnicity, smoking, alcohol use, years
resident at address, educational
qualification, life changes and perceived
effect of powerlines on health.
-
- Significantly elevated adjusted risk
ratios were found for asthma, arthritis,
type-11 diabetes and combined chronic
health problems. The results are
consistent with the hypothesis that 50-Hz
environmental magnetic fields may affect
human immune function.
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- According to the abstract:
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- "There have been several published
investigations of the possibility that
residential exposures to 50-Hz or 60-Hz
electromagnetic fields might cause
adverse psychological effects such as
suicide and depression. However, the
validity of these studies may have been
limited by research design problems such
as inadequate controlling for confounders
or inadequate measurement of exposures.
-
- The purpose of this study was to
investigate a possible relationship
between magnetic field exposure and
psychological and mental health variables
while controlling for potential
confounders and using measurement methods
that provided valid and reliable
characterisation of magnetic field
exposures.
- Five hundred and forty adult occupants of
houses sited close to transmission lines
completed neuropsychological tests in
major domains of memory and attentional
functioning, rating scales measuring
mental health, and questionnaires
regarding standard demographic variables,
psychological stressors, medical and work
history, perceived health and beliefs
about possible effects of powerline
electromagnetic fields.
-
- There were significant linear
dose-response relationships between
exposure and several psychological and
mental health variables. In particular,
higher time-integrated exposures were
associated with poorer coding-test
performance and more-adverse psychiatric
symptomatology.
-
- These results are apparently not a
secondary effect of participants' beliefs
about effects of electromagnetic fields,
gender, socioeconomic level, life
stressors, and beliefs about possible
adverse effects of electromagnetic
fields. There were significant linear
dose-response relationships between
exposure and several psychological and
mental health variables. In particular,
higher time-integrated exposures were
associated with poorer coding-test
performance and more adverse psychiatric
symptomatology.
-
- These results are apparently not a
secondary effect of participants' beliefs
about effects of electromagnetic fields,
but are more consistent with a direct
effect of chronic exposure to 50Hz
magnetic field exposure on the nervous
system."
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