Amyotrophic lateral sclerosis is a rare neurodegenerative disease of unknown origin that is currently untreatable. New research suggests that workplace exposure to magnetic fields may be responsible for the disease.
Written by Ana Sandoiu
Previous research has pointed to a variety of occupational exposures that may drive the illness. Some of these include extremely low-frequency magnetic fields (ELF-MFs), electrical shocks, metals, and toxic substances such as solvents and pesticides.
The correlations found in these studies, however, have been questioned due to methodological flaws in the analysis.
A new study aims to succeed where previous research has failed, examining the existing evidence and analyzing the effects of the above-mentioned occupational exposures on ALS mortality.
The research was carried out by scientists from Utrecht University, Maastricht University, and the University Medical Center Utrecht - all in the Netherlands - and the results were published in the journal Occupational & Environmental Medicine.
Studying the link between ALS mortality and occupational exposures
The researchers used the data available from the Netherlands Cohort Study - a large-scale, cohort study that examined diet and cancer risk in more than 58,000 men and 62,500 women.
Using job exposure matrices - a validated tool commonly used to assess occupational health hazards - the scientists estimated the occupational exposure to metals, electrical shocks, ELF-MFs, and to pesticides and solvents.
Men exposed to ELF-MFs more than twice as likely to develop ALS
Men who were occupationally exposed to high levels of ELF-MFs were 2.19 times more likely to develop ALS than those who had never been exposed to them. Additionally, those in the top tertile (or the top 30 percent) of cumulative exposure were almost twice as likely to develop ALS.
The study did not find a proportional link between ALS risk and the amount of exposure.
The authors conclude that their study "strengthens the evidence" and provides "further support for an association between occupational exposure to ELF-MF and an increased risk of ALS mortality."