Epilepsy

Do magnetic fields cause epilepsy?

 We are aware of two epidemiological studies that have looked at epilepsy (both were studies primarily looking at neurodegenerative disorders but also included epilepsy).  Neither found any association with magnetic fields.

Epidemiology. 2003 Jul;14(4):413-9; discussion 427-8.
Occupational magnetic field exposure and neurodegenerative disease.

Feychting M, Jonsson F, Pedersen NL, Ahlbom A.
SourceInstitute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.

Abstract
BACKGROUND: Several studies have identified occupational exposure to extremely low-frequency electromagnetic fields (EMF) as a potential risk factor for neurodegenerative disease, but the evidence is contradictory and inconclusive.

METHODS: We conducted a cohort study to explore these associations. We studied all economically active individuals in the Swedish 1980 census (4,812,646 subjects), and followed them for neurodegenerative disease mortality from 1981 through 1995. Information about occupation was available for 1970 and 1980. A job-exposure matrix based on magnetic field measurements was used to assess EMF exposure.

RESULTS: An increased risk of Alzheimer's disease mortality was observed among men exposed both in 1970 and 1980 (relative risk = 2.3; 95% confidence interval = 1.6-3.3 for exposure >/=0.5 microT). The associations were most pronounced for early-onset Alzheimer's disease mortality or with follow-up limited to 10 years after the last known occupation. Amyotrophic lateral sclerosis was not associated with EMF exposure, but the risk estimate with "electrical and electronics work" was 1.4 (95% confidence interval = 1.1-1.9).

CONCLUSIONS: Our study gives some support to the hypothesis that EMF exposure increases the risk of early-onset Alzheimer's disease, and suggests that magnetic field exposure may represent a late-acting influence in the disease process. Electric shock is an unlikely explanation for the increased risk of amyotrophic lateral sclerosis in "electrical and electronics work" in this study.

 

Epidemiology. 2003 Jul;14(4):420-6; discussion 427-8.
Neurodegenerative diseases in welders and other workers exposed to high levels of magnetic fields.

Håkansson N, Gustavsson P, Johansen C, Floderus B.
SourceInstitute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.

Abstract
BACKGROUND: Previous work has suggested an increase in risk of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease among workers exposed to extremely low-frequency magnetic fields (ELF-MF). We evaluated the relation between ELF-MF from occupational exposures and mortality from neurodegenerative diseases.

METHODS: The study was based on a cohort of Swedish engineering industry workers, comprising 537,692 men and 180,529 women. The cohort was matched against the 3 most recent censuses and The Causes of Death Registry. Levels of ELF-MF exposure were obtained by linking occupation according to the censuses to a job exposure matrix. We used 4 levels of exposure and considered both the primary and contributing causes of death, 1985-96.

RESULTS: The risk of Alzheimer's disease as primary or contributing cause of death increased with increasing exposure to ELF-MF among both men and women, with a relative risk (RR) of 4.0 and a 95% confidence interval (95% CI) of 1.4-11.7 in the highest exposure group for both sexes combined. There was a RR of 2.2 (95% CI: 1.0-4.7) for ALS in the highest exposure group with the suggestion of an exposure-response relationship. No evidence of increased risk was seen for Parkinson's disease or multiple sclerosis.

CONCLUSIONS: The findings support previous observations of an increased risk of Alzheimer's disease and ALS among employees occupationally exposed to ELF-MF. Further studies based on morbidity data are warranted.

 

Are people with epilepsy more sensitive to magnetic fields?

Are people with epilepsy more sensitive to magnetic fields?

There is some evidence that people with epilepsy, or with a disposition to epilepsy, may be more sensitive to the effects of induced currents.  These induced currents are the basis of most exposure limits, and the sensitivity of people with epilepsy is one of the reasons given for setting the limits for the public a factor of five lower than the limits for workers.