Occupational exposure to manganese in ferroalloy industry: Nevrobehavioral effects in a workers' cohort

Our Institute has been following for 20 years a group of workers of a ferroalloy industry in order to evaluate neurobehavioral effects due to manganese exposure. Five years after the last study we have planned another one, to evaluate differences in neuromotor e cognitive functions between exposed and controls and to perform a longitudinal evaluation of the results. Environmental and biological sampling were collected, liver and kidney functionality, haemochrome, iron metabolism and sieric prolactine were evaluated. Several tests were administered: postural evaluation, tremor, four tests of the SPES battery, Pursuing Aiming, five tests of the Luria Nebraska Motor Battery, Raven Progressive Matrices, Trail Making Test, Mood Scale, Brief Symptoms Inventory, neuropsychological symptoms questionnaire. Personal habits and working, living and clinical histories were collected. We evaluated 43 exposed workers and 40 controls. Exposure indicators resulted all significantly higher in exposed workers. Neuropsychological examination showed differences in Raven Progressive Matrices and Pursuit Aiming, higher tremor values and differences in postural evaluation between exposed and controls.