穀類研磨場所空氣細菌及真菌之分布特性

Characteristics of the distribution of airborne bacteria and fungi in grain processing plants

目標：針對穀類研磨場所空氣中之細菌及真菌等微生物進行調查，以瞭解其濃度與菌種等特性，並且評估製程與環境對其所產生之影響。方法：3家穀類研磨依照製程劃分為原料存放區、前置作業區、加工調理區及包裝區，於各區實施空氣中細菌與真菌每日三次採樣及環境條件量測與人員計數，而後進行濃度量測與菌種鑑定。結果：在3家穀類研磨作業場所中，場1細菌平均濃度為15,879 ± 6,515 CFU/m^3；場2為21,243 ± 5,258 CFU/m^3；場3為3,672±1,741CFU/m^3。場1真菌平均濃度為8,801 ± 1,566 CFU/m^3；場2為15,909±6,406 CFU/m^3；場3為3,954±1,903 CFU/m^3。3家穀類研磨場之空氣中真菌與細菌濃度場內／場外比例則介於5-10倍之間，顯示場內確有污染來源貢獻，惟三階段採樣時段與不同製程之細菌與真菌濃度，均未有觀察到統計顯著差異。整合3場細菌中優勢菌種則發現，研磨場1以Pseudoxanthomonas (61.50%)與Brevibacterium (17.74%)；研磨場2之Thermomonas (45.24%)與Micrococcus (26.81%)；場3則以Pseudoxanthomonas (57.59%)與Micrococcus (23.19%)等細菌菌種佔大多數。另真菌菌種於3間穀類研磨作業場均以Aspergillus真菌屬佔大多數。結論：穀類研磨場所空氣中之細菌與真菌濃度顯著高於場外，建議可加強通風換氣與個人防護等職業衛生措施，以確保作業人員健康。

Objectives: The aim of this study was to investigate the characteristics of the distribution of airborne microbes in three grain processing plants. Methods: Airborne bacteria and fungi were collected three times each day in four processing areas and outdoor locations at each plant during the study period. Results: In the three grain processing plants, the average bacterial concentrations were 15,879 ± 6,515 CFU/m^3, 21,243 ± 5,258 CFU/m^3 and 3,672 ± 1,741 CFU/m^3, respectively. The average fungal concentrations were 8,801 ± 1,566 CFU/m^3, 15,909 ± 6,406 CFU/m^3 and 3,954 ± 1,903 CFU/m^3, respectively. The ratio of indoor/outdoor microbial concentration was 5-10. In grain processing plant Number1, Pseudoxanthomonas (61.50%) and Brevibacterium (17.74%) were the predominant airborne bacteria. Thermomonas (45.24%) and Micrococcus (26.81%) and Pseudoxanthomonas (57.59%) and Micrococcus (23.19%) were the predominant bacteria in plants Number 2. and 3, respectively. Aspergillus (39.47%~79.72%) was the sole dominant airborne fungus found in all three plants. Conclusions: Grain processing plants may have high concentrations of airborne microbes inside them. Improvements in the rate of ventilation and local exhaust equipment should be considered in order to control biological contamination. We also suggest that workers should wear personal protective equipment to ensure occupational health.