ABSTRACT
Objective To summarize the clinical and laboratory features of chronic manganese poisoning. Methods A retrospective analysis was conducted on the clinical data of 4 cases with chronic manganese poisoning, including gener?al information, medical history, clinical manifestations, laboratory examination such as electrophysiological and imaging. Results Patients with chronic manganese poisoning mainly presented with mild mental disorder and autonomic nerve dis?order during early stage and then gradually developed extrapyramidal symptoms and signs. The laboratory examination of chronic manganese poisoning lacked of specificity. EMG showed neurogenic damage in 3 cases and normality in 1 case. EEG showed slightly increased full guide slow wave in 1 case and normality in 3 cases. cranial MRI revealed the damag?es in bilateral symmetry of the basal ganglia nuclei in 4 cases of Chronic manganese poisoning. There was no significant correlation between the changes of urinary manganese level before or after treatment and the clinical manifestations. Conclusions Although there is lack of specific clinical manifestations of chronic manganese poisoning, the possibility of this disease should be considered when patients with mild mental disorders or autonomic nerve disorder with or without extrapyramidal symptoms. The main treatment of chronic manganese poisoning includes excretion of manganese, symp?tomatic and supportive treatment. Patients usually have the sequelae of tremor, muscle tension, and other symptoms.
ABSTRACT
To estimate the manganese (Mn, below) exposure of workers in the ferromanganese manufacture factory and to evaluate its health effects, airborne, blood and urine Mn concentration measurements, questionnaire and other neurologic examinations were performed on 80 Mn-handing productive male workers (exposed group), 47 non-Mn-handling productive male workers (internal control group) and 144 productive male workers in other factory (external control group). The results obtained were as follows; The highest airborne Mn fume concentration among the work process was found at charging (0.42 mg/m3), and ferromanganese crushing process (1.14 mg/m3) was the highest in Mn dust. However all of them were below threshold limit value. Mean Mn concentrations in blood and urine of crushing workers were higher than those of other part workers. Among all of them, workers whose urine Mn concentration were exceed normal reference level (10 microgram/l) were 31 (18.5%). There was statistically significant correlation between airborne and urine Mn concentration (r=0.60), and so between airborne and blood Mn concentration (r=0.49), while there was no statistically significant correlation between blood and urine Mn concentration. Mean Mn concentration in airborne (0.60 mg/m3), urine (6.92 microgram/l) and blood (3.16 microgram/dl) in exposed group were significantly higher than those of control groups (p<0.01). Clinical symptoms such as excessive sweating, hypoesthesia, libido change, anosmia, decreased visual acuity and difficulty in writing showed higher positive rate in exposed group. Positive rate of clinical signs such as eye blinking and masked face in exposed group was higher than external control group. However clinical and laboratory findings such as blood pressure, blood chemistry, grip strength in exposed group were not statistically different from those of control groups. The results suggested that further studies were followed to evaluate the workers whose blood Mn concentration were below normal reference level but urine Mn concentrations above normal reference level, and to establish the questionnaire and the diagnostic tools to detect the Mn poisoning workers early.