REPEATED NEUROBEHAVIORAL INVESTIGATIONS IN WORKERS EXPOSED TO MERCURYIN A CHLORALKALI PLANT

Mercury exposed workers of a chloralkali electrolysis plant were inves tigated with neurobehavioral methods. At the beginning of the investig ation an average exposure of 12 years was stated. Four periods of inve stigations were carried out over the course of 7 years. A low exposed group (n=34-50, 21-26 mu g Hg/l Urine) and a high exposed group (n=14- 21, 111-152 mu g/l Urine) were defined for each of the time periods us ing 53 mu g/l Urine as discriminating level. Controls (n=37-43) were r ecruited from non-exposed departments of the factory. Age, verbal inte lligence and gender were controlled statistically to reduce potential confounding. Symptoms and personality traits did not covary significan tly with the exposure. Finger dexterity, tapping, and aiming were vari ables out of 13 performance measurements, which showed repeatedly a lo wer level of performance corresponding with increasing current exposur e. However, dose-response relations could not be demonstrated by parti al correlations to the concentration of mercury in Urine. Subgroups of 30 controls, 37 low exposed and 14 high exposed workers were examined in a follow-up study with repeated measurements. Significant exposure effects were shown for finger dexterity and aiming. (C) 1996 Inter Pr ess, Inc.