Study type: Epidemiological study (observational study)

Residence near power lines and mortality from neurodegenerative diseases: longitudinal study of the Swiss population. epidem.

Published in: Am J Epidemiol 2009; 169 (2): 167-175

Aim of study (acc. to author)

A longitudinal study was conducted in Switzerland to investigate the relation between residential magnetic field exposure from power lines and mortality from neurodegenerative diseases.

Further details

Exposure by magnetic fields was assessed by calculating the distance of the residence to the nearest power line.

Endpoint/type of risk estimation

Type of risk estimation: (hazard ratio)

Exposure

Assessment

Exposure groups

Group Description
Reference group 1 distance of residence to 220 - 380 kV power line: ≥ 600 m
Group 2 distance of residence to 220 - 380 kV power line: 200 < 600 m
Group 3 distance of residence to 220 - 380 kV power line: 50 < 200 m
Group 4 distance of residence to 220 - 380 kV power line: 0 < 50 m

Population

Study size

Type Value
Total 7,290,000
Eligible 4,650,000
Other:

follow-up: 22.82 million person-years

Statistical analysis method: ( adjustment: )

Conclusion (acc. to author)

9.2 % of the Swiss population live within 600 m of a 220 or 380 kV power line. During the study period 282,378 deaths from all causes were registered. The hazard ratio of Alzheimer disease for persons living within 50 m from a power line was 1.24 (CI: 0.80; 1.92). Beyond 50 m there was little evidence of an increased risk. A dose-response relation with respect to years of residence within 50 m of a power line was observed: the hazard ratio was 2.00 (CI: 1.21; 3.33) for persons living for 15 years in the vicinity of a power line. For senile dementia, the same pattern was observed, however the association tended to be weaker. No increased risk was found for Parkinson disease, amyotrophic lateral sclerosis and multiple sclerosis.
The authors concluded that the results indicate a possible association between magnetic fields of power lines and the risks of Alzheimer disease and senile dementia.

Limitations (acc. to author)

Despite the large sample size, the findings should be interpreted with caution because of the lack of known biologic mechanisms.

Study funded by

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