Researchers have discovered that workers who are exposed to high levels of electromagnetic fields may be at higher risk of developing deadly motor neurone disease.

According to a study published in The BMJ weekly medical journal, workplace exposure to very low frequency electromagnetic fields may be linked to a doubling in risk of developing the most common form of motor neurone disease, Amyotrophic Lateral Sclerosis (ALS).

Also known as Lou Gehrig's disease, ALS hit headlines in 2014 with the "Ice Bucket Challenge", which saw people upload videos of themselves to the internet pouring cold water over their heads in a bid to raise awareness about the disease. Internationally-renown British physicist Stephen Hawking suffers from ALS.

The deadly disease leads to a progressive degeneration of the motor nerve cells in the brain and spinal cord and those affected usually die within a few years of diagnosis.

"Those whose jobs had exposed them to high levels of extremely low electromagnetic fields were more than twice as likely to develop ALS as those who had never been exposed," the study has found.

Electric grid installers, cable jointers, welders and aircraft pilots were some of those with high exposure levels to electromagnetic fields.

Researchers reviewed medical records of about 120,000 men and women who were monitored for 17 years starting from the age of 55 to 69.

Work histories detailed exposure to the five suspect agents, including electromagnetic fields, electric shocks, solvents, metals, and pesticides.

The only significant link between ALS with the suspected sources were electromagnetic fields, the researchers found.

"This study has much better information on exposure to magnetic fields than previous studies," said Neil Pearce, a professor of epidemiology and biostatistics at the London School of Hygiene and Tropical Medicine.

"If this finding is real, it is important as it identifies a new, preventable cause of ALS," he added.

There is currently no cure for the disease.

A satellite dish is seen at the headquarters of European Broadcasting Union (EBU), March 23, 2017, Geneva, Switzerland. (Photo by AFP)

ALS is a relatively rare disease which occurs on average among two new cases per 100,000 people every year.

The disease typically occurs among men aged between 55 and 65.