Summary: | 碩士 === 長榮大學 === 職業安全與衛生學系碩士班 === 97 === Hot-dip galvanizing is the technique widely used for steel corrosion protection in developed countries. Currently a majority of steel roll manufacturing factories are using the technique in their manufacturing processes. Metal fume is produced from the molten metals in the manufacturing processes. The metal fume can have the elements or their oxides of zinc, nickel, lead, chromium, manganese etc. The workers in the workplace can have adverse health effects due to exposure to these metals. Few studies were conducted on the exploration of whether the workers of hot-dip galvanizing manufacturing processes were exposed to the exceeding levels of the permissible exposure limits of the metals. More studies are needed for this topic. In this study the workers in a hot-dip galvanized steel roll manufacturing factory were recruited for personal breathing-zone exposure measurements of metal fumes and urine sample collection. Area samples of metal fumes were also taken when the personal exposure measurements were conducted. Each personal exposure sample was taken by using an IOM with a 25 mm mixed cellulose ester (MCE) filter. The area sample was taken by using a cassette with a 37 mm MCE filter. Urine samples of the workers were collected during the work time of a normal 8-hour workday. The metal contents of zinc, nickel, chromium lead and manganese of the collected samples were analyzed by atomic absorption spectrometry (Varian AAS 220FS, Australia) with a flame or graphite tube atomizer. During the period of exposure sampling, the characteristics of manufacturing processes, work activity and environmental setting were observed and recorded for exposure assessment modeling. The mean (±standard deviation) concentrations of zinc, nickel, lead, chromium, and manganese measured by the area samples were 5.36±2.74, 0.10±0.06, 0.25±0.12, 0.61±0.33 and 0.081±0.034 mg/m3, respectively. The mean (±standard deviation) concentrations of zinc, nickel, lead, chromium, and manganese measured from the personal samples were 7.90±9.54、0.11±0.13、0.28±0.29、0.28±0.32 mg/m3 respectively. The results indicated that the workers’ exposure to the metals exceeded the threshold limit values suggested by the ACGIH. The mean (±standard deviation) concentrations of chromium in the urine samples were 11.397(±8.25) g/dL which far exceeded the ACGIH’s biological exposure indices. Effective exposure control strategies are required to reduce the metal exposure of the workers in the manufacturing processes.
|