Study type: Epidemiological study (observational study)

Electromagnetic fields and cancer in children residing near Norwegian high-voltage power lines. epidem.

Published in: Am J Epidemiol 1997; 145 (3): 219-226

Aim of study (acc. to author)

A nested case-control study was conducted in Norway to test the hypothesis that exposure to electric and magnetic fields generated by high-voltage power lines increases the risk of cancer in childhood.

Further details

All children living within the wards in close distance to high-voltage power lines were linked to the Cancer Registry of Norway to identify the cases of cancer. Exposure was calculated on the basis power line characteristics and distance.

Endpoint/type of risk estimation

Type of risk estimation: (odds ratio (OR))

Exposure

Assessment

Exposure groups

Group Description
Reference group 1 time-weighted average exposure to magnetic fields, from birth to diagnosis: < 0.05 µT
Group 2 time-weighted average exposure to magnetic fields, from birth to diagnosis: 0.05 - < 0.14 µT
Group 3 time-weighted average exposure to magnetic fields, from birth to diagnosis: ≥ 0.14 µT
Reference group 4 distance of address to closest power line: ≥ 101 m
Group 5 distance of address to closest power line: 51 - 101 m
Group 6 distance of address to closest power line: < 51 m
Reference group 7 calculated magnetic fields closest in time to diagnosis: < 0.05 µT
Group 8 calculated magnetic fields closest in time to diagnosis: 0.05 - < 0.14 µT
Group 9 calculated magnetic fields closest in time to diagnosis: ≥ 0.14 µT
Group 10 calculated magnetic fields during first year of life: 0.05 - < 0.14 µT
Reference group 11 calculated magnetic fields during first year of life: < 0.05 µT
Group 12 calculated magnetic fields during first year of life: ≥ 0.14 µT

Population

Case group

Control group

Study size

Cases Controls
Eligible 532 2,112
Participants 500 2,004
Other:

cohort of 168 450 children living within the selected wards at least one of the years 1960, 1970, 1980, 1985, 1987 or 1989

Statistical analysis method: (adjustment: )

Conclusion (acc. to author)

Time-weighted average exposure of magnetic fields above 0.2 µT was calculated for only 10 cases of cancer . No association between time-weighted average or cumulative exposure to magnetic fields and childhood cancer at all sides combined, brain tumor, lypmphoma and leukemia was found. For cancers at other sites, an elevated risk in some of the highest exposure categories was observed.
The findings provide little support for an association between exposure to magnetic fields and childhood cancer and no support for an association between childhood leukemia and magnetic fields.

Limitations (acc. to author)

No firm conclusions can be drawn because of the small numbers involved.

Study funded by

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