Laitinen S, Kangas J, Kotimaa M, Liesivuori J, Martikainen P J, Nevalainen A, Sarantila R, Husman K
Kuopio Regional Institute of Occupational Health, Finland.
Am Ind Hyg Assoc J. 1994 Nov;55(11):1055-60. doi: 10.1080/15428119491018330.
A study of sewage workers' exposure to airborne culturable bacteria and inhaled endotoxins was performed at nine waste-water treatment plants that treat mainly industrial effluents. Airborne endotoxins were collected on glass fiber filters and analyzed using a chromogenic limulus assay. Endotoxin concentrations measured in the immediate vicinity of the waste-water treatment process varied from 0.1 to 350 ng/m3. The eight-hour time weighted average concentrations of endotoxin to which workers were exposed exceeded the suggested exposure limit (30 ng/m3 endotoxin) at four of the plants. Air samples of culturable bacteria concentrations varied between 10 and 10(5) colony-forming units/m3. Of the particles carrying culturable bacteria, 88% had an aerodynamic diameter of less than 4.7 microns. The most common genera of airborne gram-negative bacteria were acinetobacter, citrobacter, enterobacter, klebsiella, and pseudomonas. High levels of exposure to bacteria and bacterial endotoxin usually were related to certain phases of the treatment process. The microbiological contamination of air was highest near the inlets where incoming wastewater entered the basins, in the sludge treatment area, and inside the biofilter tower. In these spaces it is necessary to control and reduce exposure to airborne bacteria and endotoxin at wastewater plants.
在九个主要处理工业废水的污水处理厂，对污水工人接触空气中可培养细菌和吸入内毒素的情况进行了一项研究。空气中的内毒素收集在玻璃纤维滤膜上，并用显色鲎试剂法进行分析。在废水处理过程的紧邻区域测得的内毒素浓度在0.1至350 ng/m³之间。在其中四个工厂，工人接触的内毒素八小时时间加权平均浓度超过了建议的接触限值（30 ng/m³内毒素）。可培养细菌浓度的空气样本在10至10⁵菌落形成单位/m³之间变化。在携带可培养细菌的颗粒中，88%的空气动力学直径小于4.7微米。空气中革兰氏阴性菌最常见的属是不动杆菌属、柠檬酸杆菌属、肠杆菌属、克雷伯菌属和假单胞菌属。细菌和细菌内毒素的高暴露水平通常与处理过程的某些阶段有关。空气的微生物污染在进水进入水池的入口附近、污泥处理区域和生物滤塔内部最高。在这些区域，有必要在污水处理厂控制和减少对空气中细菌和内毒素的暴露。
