Manganese exposure in steel smelters a health hazard to the nervous system

Arne Wennberg, Anders Iregren, Göran Struwe, G Cizinsky, Maud Hagman, L Johansson
1991 Scandinavian Journal of Work, Environment and Health  
WENNBERG A, lREGREN A, STRUWEG, CIZINSKY G, HAGMAN M, JOHANSSON L. Manganese exposure in steel smelters a health hazard to the nervous system. Scand J Work En viron Health 1991 ; 17:255-62. In a study of the effects of low-level exposure to manganese (0.19-1.39 mg/rn! for 1-45 years) 30 men (aged 20-64 years) from two steel smelting works and 60 unexposed referents (aged 22-65years) wereexamined with the use of a generalhealth inquiry, electroencephalography, event-related auditory evoked
more » ... ials, brain-stem auditory evokedpotentials, diadochokinesometry, simpleand complex reaction time, finger tapping, digit span, mental arithmetic, vocabulary, a coding task, manual dexterity, symptoms, and mood scales, the diagnostic interview scheme, a dynamicrating scalefor neurasthenic syndrome, and a comprehensivepsychopathologicalrating scale. No group differences were found in the electroencephalography or the psychiatric examinations. However, there were increased frequencies of some symptoms, the diadochokinesis was slower, the P-300latency and reaction time wereincreased, and finger-tapping and digit-span performance were impaired in the exposed group . These effects were interpreted as early (subclinical) signs of disturbances of the same type as parkinsonism. Mangan ese ha s a to xic effect on the centra l ner vou s system (I ). A t high exposure levels th ere are two types of effects. In th e acute phase psych iatric sympt oms dominate ("manganese madness" ) with hallucinations, emo tional labili ty, and compulsive and aber rant beha vior. Later , neurological symptoms with muscular wea kness, impa ired speech, headache, clum siness, tremor, mild rigidit y, and hypokinetic (masklike) facial expr essio ns appear. These symptoms are similar to thos e seen in Parkinson's disease, and they are typical of chr onic manganese poi soning. Micro scop ic examinat ion of brains from subjects poi soned by mangan ese has revealed lesions in the extrapyramid al structures (substantia nigra, globus pallidus, subthalamic nucl eus, caudate nucleus, and putamen) similar to those found in Parkinson's disease. Man gani sm was first described in 1837 for mangan ese min ers (2) and later, in 1907, for workers who had pulveri zed pyrolusite (3). There ar e also later case reports (eg, m iner s in Japan, Chile, Morocco , Cuba, Ind ia , Mexico, th e Soviet Union, and the United State s) (4). In all the se cases , the exposure levels were
doi:10.5271/sjweh.1705 fatcat:qlqak5s5mvb6fbx2ryt3qf5gvq