養豬場作業環境暴露危害研究

Exposure of Bioaerosols and Coexistent Contaminants in Swine Feed Buildings

文獻指出養豬工人表現出較高比率的呼吸道疾患與肺功能不適的現象，而研究亦發現存在於養豬場的生物性氣膠與粉塵對引發此一健康效應上扮演重要角色，然目前國內對此問題之了解仍極有限。本研究即希望能對國內養豬場生物性氣膠暴露危害情況予以量化，並同時評估其他空氣污染物。研究對象為國內六所養豬頭數一萬頭以上之養豬場。空氣中微生物係以玻璃液體衝擊瓶（AGI）或單階式安德森微生物採樣器（AMS）採集，並經培養後計數形成菌落：粉塵與三種氣體（氨氣、二氧化碳與硫化氫）則分別以濾紙秤重及擴散式檢知管測量；細菌內毒素則以Limulus amoebocyte lysate方法定量。結果顯示，豬舍內空氣中總細菌平均濃度為3.3 x 105 CFU/m3，革蘭氏陰性細菌平均濃度則為143.7 CFU/m3，總真菌濃度則在103CFU/m3範圍，並以Cladosporium為主要菌屬。總細菌內毒素平均濃度為139.53 EU/m3，個人可呼吸性細菌內毒素平均濃度則為46.96EU/m3。總粉塵平均濃度為0.15-0.34 mg/m3，個人可呼吸粉塵平均為 0.14 mg/m3。氨氣與硫化氫分別低於5 ppm與0.2 ppm，二氧化碳則介於600ppm與894 ppm之間。比較不同豬舍發現，肉豬後期舍為微生物與氣體暴露較高之豬舍，保育舍中總粉塵與總內毒素量亦高於其他舍別。另外，民營豬舍內污染情形均較公營豬舍嚴重。未來宜應加強其作業場所衛生之管理。

Literature has shown that swine workers may suffer from high prevalence of respiratory symptoms, and has suggested that bioaerosols and airborne dusts present in swine feed buildings may play an important role. However, very limited information is available in Taiwan. This study was to quantify the exposure of bioaerosols and other coexistent contaminants within swine feed stalls. Six swine feed fields with more than 10,000 pigs were selected. Airborne concentrations of bacteria and fungi were determined by collecting them onto appropriate media using All-glass impinger or single-stage Andersen Microbial Sampler. Gases (NH3, CO2 and H2S) and airborne duss were quantified respectively by using Drager diffusion tubes and filterweighing method. The Limulusamoebocyte lysate assay was selected to determine airborne endotoxin. Results showed the mean concentration of total bacteria and gram-negative bacteria was 3.3 x lO5 CFU/m3 and 143.7 CFU/m3, respectively. The airborne concentration of total fungi was about 103 CFU/m3, with Cladosporium as the most dominant species. Average concentration of total bacterial endotoxin was calculated to be 139.53 EU/m3, while that for respirable endotoxin was 46.96 EU/m3. Mean concentration of total dust was between 0.15 mg/m3 and 0.34 mg/m3, with average level of respirable dust of 0.14 mg/m3. The respective concentrations of NH3, CO2 and H2S were measured to be less than 5 ppm, 600~894 ppm and less than 0.2 ppm. It also indicated that the finishing house present the highest exposure risk to airborne microorganisms, NH3, CO2 and H2S. Airborne concentrations of total dust and endotoxin in the nursing house were higher than those in other swine houses. The results suggest that it is necessary to improve the environmental sanitation in swine feed workplaces.