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-handing productive male workers (internal control group) and 144 productive male workers in other factory (external control group).
@ES The results obtained were as follows:
@EN The highest airborne Mn fume concentration among the work process was found at charging (0.42mg/m*), and ferromanganese crushing process (1.14 mg/m*) 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 (10μg/l)were 31 (18.5%), There was statistically
significant
correlation between airborne and urine Mn concentrations (r=0.60), and so between airborne and blood Mn concentrations (r=0.49), while there was no statistically significant correlation between blood and urine Mn concentration. Mean Mn
concentrations in
airborne (0.60mg/m*), urine (6.92μg/l) and blood (3.16μg/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 trom those of control groups.
The results suggested that further studies were followed to evaluate the workers whose blood Mn concentrations 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.
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