Abstract

Blood and urine samples were taken from 447 welders exposed to manganese containing welding fumes and 127 office workers not exposed to welding fumes as a control. The air samples were analyzed by flame atomic absorption spectrophotometer (Varian 30A, Australia), and blood and urine samples were analyzed by flameless atomic absorption spectrophotometer(Z-8100, Hibachi, Japan). Data were evaluated in accordance with type of industry, smoking habits, and work duration. The results obtained were as follows: 1. The limit of detection(LOD) levels of manganese in blood and urine were 0.11 microgram/100ml of and 0.14 microgram/l, respectively. Our results of manganese concentration were shown within +/-2 standard deviation which was the upper and lower warning limit (UWL or LWL) on quality control chart. 2. The airborne concentrations of manganese in welding workplaces were 0.067 mg/m3 showing differences by type of industry ; 0.017 mg/m3 in automobile assembly and manufacturing industries, 0.084 mg/m3 in steel heavy industries and 0.180 mg/m3 in shipyards. 3. The blood manganese concentrations showed differences by type of industry showing the highest values of 1.70 microgram/100m1 in shipyards, 1.24 microgram/100m1 in automobile assembly and manufacturing industries and 1.11 microgram/100ml in steel heavy industries. Urinary manganese concentration corrected by urinary creatinine concentrations was 0.34 microgram/g creatinine in automobile assembly and manufacturing industries, 0.43 microgram/g creatinine in steel heavy industries and 0.48 microgram/g creatinine in shipyards. There were no difference urinary manganese concentrations by type of industry. 4. The overall blood manganese concentration was 1.26 microgram/100ml, and urinary manganese concentration was 0.35 microgram/g creatinine in welders. In contrast to these values, blood and urinary manganese concentrations were lower in control group showing 0.73 microgram/100m1, and 0.28 microgram/g creatinine, respectively. 5. Smoking habits did not seem to affect on blood and urinary manganese concentrations both in welders and office workers. 6. Blood manganese concentrations were significantly higher in welder who had worked longer than 10 years than in welder who had worked less than 10 years. 7. The blood manganese concentrations were significantly correlated to airborne manganese concentrations(r=0.318, n=64), work duration(r=0.425, n=538), and cumulative exposure indices(CEI) (r=0.354, n=64).

• Keywords: Manganese in blood;Urine and airborne;Work duration;Cumulative exposure index (CEI);Welder