They selected a sample of almost 6,000 workers from a total of 139,000 for detailed study. The average length of time worked in the industry was 16 years. The researchers found that suicide deaths were twice as high among those employees whose work regularly exposed them to electromagnetic radiation. Among those workers who committed suicide before the age of 50, the link was even stronger. Major depression is not usually associated with physical health and is more common in younger people.
Minor depression occurs later in life and is often linked with medical illness.
The authors suggest that electromagnetic fields may reduce the production of melatonin, a hormone that maintains the normal daily rhythms of the body, including the sleep and wake cycle. Reduced levels of melatonin are associated with depression. This may ultimately lead to suicide. However, Mr van Wijngaarden said it would be premature to consider new guidelines on exposure to electromagnetic radiation. Dr Cosmo Hallstrom, a consultant psychiatrist from the Charter Clinic in London, said electromagnetic radiation had been associated with disruption to levels of seratonin, a brain chemical known to be linked to depression.