Mortality from Alzheimer’s, motor neurone and Parkinson’s disease in relation to magnetic field exposure: findings from the study of UK electricity generation and transmission workers, 1973-2004.

Abstract

Background: There are a number of reports linking magnetic field exposure to increased risks of Alzheimer’s disease and motor neurone disease. Methods: The mortality experienced by a cohort of 83,997 employees of the former Central Electricity Generating Board of England and Wales was investigated for the period 1973-2004. All employees were employed for at least six months with some employment in the period 1973-82. Computerised work histories were available for 79,972 study subjects for the period 1971-93. Information on job and facility (location) were used to estimate exposures to magnetic fields. Two analytical approaches were used to evaluate risks, indirect standardisation (n = 83,997) and Poisson regression (n = 79,972). Results: Based on serial mortality rates for England and Wales, deaths from Alzheimer’s disease and motor neurone disease were unexceptional. There was an excess of deaths from Parkinson’s disease of borderline significance. No statistically significant trends were shown for risks of any of these diseases to increase with lifetime cumulative exposure to magnetic fields (RR per 10mT.y with 95% confidence interval: Alzheimer’s disease 1.10 (0.90 to 1.33); motor neurone disease 1.06 (0.86 to 1.32); Parkinson’s disease 0.88 (0.74 to 1.05)) Conclusions: There is no evidence that UK electricity generation and transmission workers have suffered elevated risks from neurodegenerative diseases as a consequence of exposure to magnetic fields.