Symptoms of the musculoskeletal system and exposure to magnetic fields in an aluminium plant.

OBJECTIVE The study was performed to examine the influence of the exposure to magnetic fields in the potrooms of an electrolysis plant on the occurrence of musculoskeletal symptoms among the employees. The study was performed after much discussion and worry in the aluminium industry about this issue. METHODS A retrospective cohort study was performed at an aluminium plant. The occurrence of musculoskeletal symptoms registered at health controls performed by the occupational health care unit in 1986 and 1991 was assessed from employees exposed to magnetic fields in the potrooms (n = 342) and from a control group (n = 277). The data were collected before the discussion about the effects of magnetic fields started. The exposure to static magnetic fields was found to be 3-20 mT inside the potrooms. Ripple components (alternating currents (AC fields)) were registered as well. RESULTS No difference between the exposed and unexposed groups was found for the reported musculoskeletal symptoms in 1986 or in 1991. CONCLUSIONS There seems to be no relation between work in potrooms with exposure to static magnetic fields and the occurrence of musculoskeletal symptoms.