Magnetic fields of high voltage power lines and risk of cancer in Finnish adults: nationwide cohort study.
OBJECTIVE
To investigate the risk of cancer in association with magnetic fields in Finnish adults living close to high voltage power lines.


METHODS
Nationwide cohort study.


METHODS
383,700 people who lived during 1970-89 within 500 metres of overhead power lines of 110-400 kV in a magnetic field calculated to be > or = 0.01 microT. Study subjects were identified by record linkages of nationwide registers.


METHODS
Numbers of observed and expected cases of cancer, standardised incidence ratios, and incidence rate ratios adjusted for sex, age, calendar year, and social class--for example, by continuous cumulative exposure per 1 microT year with 95% confidence intervals from multiplicative models for all cancers combined and 21 selected types.


RESULTS
Altogether 8415 cases of cancer were observed (standardised incidence ratio 0.98; 95% confidence interval 0.96 to 1.00) in adults. All incidence rate ratios for both sexes combined were non-significant and between 0.91 and 1.11. Significant excesses were observed in multiple myeloma in men (incidence rate ratio 1.22) and in colon cancer in women (1.16).


CONCLUSIONS
Typical residential magnetic fields generated by high voltage power lines do not seem to be related to the risk of overall cancer in adults. The previously suggested associations between extremely low frequency magnetic fields and tumours of the nervous system, lymphoma, and leukaemia in adults and breast cancer in women were not confirmed.
Department of Public Health, University of Helsinki, Finland.
P K
PK
Verkasalo
E
E
Pukkala
J
J
Kaprio
K V
KV
Heikkilä
M
M
Koskenvuo
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000453:epidemiology; D004559:Electric Wiring; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D005387:Finland / Q000453:epidemiology; D019337:Hematologic Neoplasms / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008545:Melanoma / Q000453:epidemiology; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000453:epidemiology; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D009423:Nervous System Neoplasms / Q000453:epidemiology; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology