鉻化砷酸銅(chromated copper arsenate, CCA)為國內外最普遍使用之水溶性木材防腐劑。為了解木材防腐廠員工之CCA暴露狀況以及影響濃度因子,由防腐廠員工配帶IOM採樣器進行個人空氣採樣,同時亦詳細紀錄工廠規模、當日工作量、工作類別、木材種類、防腐強度、靜置時間、注藥罐運作數目及通風狀況等。金屬分析以氫化物產生原子吸收光譜儀(Varian 220 FS)、石墨爐原子吸收光譜儀(Varian 220 FS)及紫外可見分光光度計(Varian Cary 50)分別進行砷、鉻及六價鉻之測定。資料分析採用SAS V8.2 統計軟體,利用ANOVA、T-test及無母數等分析方法,檢定不同作業條件勞工暴露之差異性及作業現場各項因子與空氣採樣結果之相關性。從結果發現防腐廠操作員工八小時之平均砷暴露量為2.9 µg/m3,鉻為2.3 µg/m3,六價鉻為0.1 µg/m3,均低於PELs(As:10 µg/m3,Cr:500 µg/m3,Cr+6:100 µg/m3)。而CCA操作員工之個人暴露不但高於其他員工與辦公室行政人員(p<0.05),且注藥罐附近區域之空氣砷、鉻濃度亦明顯高於廠內其他工作場所(p<0.05)。本研究另發現加裝局部排氣設備及延長後真空時間能有效地降低空氣中之CCA含量(p<0.05),而愈接近注藥罐之區域暴露劑量有愈高之趨勢,操作防腐設備之員工應確實佩帶呼吸防護具以降低個人暴露。
Chromated copper arsenate(CCA)is the compound used worldwide for wood preservation. In order to assess the potential inhalation exposure of workers to preservative fluids used in industrial timber pre-treatment as well as the factors influencing exposure levels, IOM samplers were used to collect the inhalable dusts and information such as factory scale, workload, job category, wood type, preservative strength, treatment time and ventilation condition were also collected. Airborne metal levels were analyzed with hydride generation atomic absorption spectrometry(Varian 220FS), atomic absorption spectrometry with graphite furnace (Varian 220FS)and UV-Vis spectrophotometer(Varian Cary 50). SAS(V8.2)was used to perform the data analysis. The results showed the mean concentrations of arsenic, chromium and hexavalent chromium were 2.9 µg/m3, 2.3 µg/m3, and 0.1 µg/m3, respectively, and were all below the PELs(As:10 µg/m3, Cr:500 µg/m3, Cr+6:100 µg/m3). The airborne concentrations of arsenic and chromium in the factory with local exhaust system(LES) were significantly reduced, and the workers handling wood preservative had higher exposure level than other employees(p<0.05). The airborne metals concentration measured near the chamber were found to be significantly higher than those in other regions in the factories(p<0.0001). This study found that the LES and the prolonged final vacuum time could effectively lower the airborne metals concentrations(p<0.05), and the workers near the impregnation chamber should wear respiratory protective devices to avoid overexposure.