木材加工場之細菌性生物氣膠特性研究

Characteristics of Bacteria Bioaerosol in Wood Processing Workplace

本研究選擇以木材鋸屑作業環境，進行細菌菌種鑑定及內毒素暴露採樣調查。實驗利用安德森六階、Biosampler、AGI-30及SKC鋁製旋風分離器搭配PC濾紙，以評估木材加工廠細菌在環境中濃度，及評估其可呼吸性木塵濃度。研究結果顯示：工廠所採集之細菌經鑑定後發現以Bacillus spp.及Staphylococcus spp.為主要優勢菌種。以革蘭氏陽性菌為多數，其中以Bacillus spp.為優勢菌屬。在細菌濃度方面：裁切區大於原木堆置區之濃度，應與裁切時木材鋸屑飛散有關。根據統計結果顯示：革蘭氏陽性菌與生物氣膠採樣器種類有顯著差異（p值為0.0002）。溫、濕度部分則與革蘭氏陰性菌濃度有顯著差異（p<0.05）。在生物安全等級分類部分，第二級之細菌生物氣膠佔51.7%。在作業環境中，所有生物氣膠採樣器均顯示以Pantoea agglomerans（培養出）所偵測到內毒素含量較高，為0.8053 EU/m3。以SKC旋風分離器搭配PC濾紙，所採集之總內毒素濃度範圍為2.1639×10-6~5.1850×10-6 EU/m3。目前作業環境空氣中，可呼吸性木塵濃度及內毒素暴露濃度，並無完整規範。建議未來可加以規範，以防範過量職業暴露。

This experiment chose the wood processing environment to conduct bacterial strain identification and endotoxin exposure investigations.The experiment used the single-stage and six-stage Anderson samplers, Biosampler, AGI-30 and SKC aluminum cyclone with PC filter paper to evaluate the concentration of the bacteria and respirable wood dust in the wood processing plant. The results show that the dominant strains identified from the bacteria sampled at the plant were Bacillus spp. and staphylococcus spp. Among these, the majority were gram-positive bacteria, whose dominant strain was Bacillus spp.. The bacteria concentration in the cutting area was greater than that in the logging area, which should be related to the flying of wood dust during the cutting. The statistical results indicated that gram-positive bacteria differ significantly from the bioaerosol sampler types (P= 0.0002). They were also significantly different from the concentration of gram-negative bacteria in terms of temperature and humidity (P<0.05). Regarding the biological safety level (BSL) classification, the class II bacterial bioaerosol accounted for 51.7%. In the working environment, all bioaerosol samplers showed that the endotoxin content detected in Pantoea agglomerans (cultured) was much higher, being 0.8053 EU/m3. The total endotoxin concentration range collected by SKC cyclone separator with PC filter paper was 2.1639×10-6~5.1850×10-6 EU/m3. At present, there are no complete standards on the content limit of respirable wood dust concentration and the exposure limit of endotoxin in the working environment. Standards are recommended to be imposed in the future to prevent the increase of occupational exposure.