May 24, 2007 (Insidermedicine) Very low frequency magnetic fields can be linked to cancer but the public is not at risk, say researchers in an article published in Occupational and Environmental Medicine.

Electric and magnetic fields are areas of energy that surround any electrical device, and are produced by power lines, electrical wiring and appliances. While electric fields are easily shielded or weakened by walls and other objects, magnetic fields can actually penetrate the body, and thus have been studied in relation to cancer. Past studies of magnetic field exposure in adults showed very small increases in leukemia and brain tumors. However, more recent, well-conducted studies have shown inconsistent associations with leukemia, brain tumors, and breast cancer.

In the present study, researchers monitored more than 20,000 Swiss railway workers for 30 years. This particular group was chosen because their work exposes them to much higher levels of electromagnetic field radiation than the general population, although exposure varied widely depending on where they were posted. For example, the train drivers were exposed to around three times the levels of shunting yard engineers and nine times the levels of ticket collectors on trains. Station masters were exposed to the lowest levels.

After collecting information on the deaths of the employees, it was found that deaths from all causes were slightly higher among shunting yard engineers and train ticket collectors than among drivers. However, the drivers were four times as likely to die of myeloid leukemia, and over three times as likely to die of Hodgkin’s lymphoma as station masters.

The researchers say that while passengers are in no danger, care should be taken to limit the exposure among train drivers and others working near electromagnetic fields.

Reporting for Insidermedicine, I’m Dr. Petra Joller.