Fracchia L, Pietronave S, Rinaldi M, Martinotti M G
Department of Chemical, Food, Pharmaceutical and Pharmacological Sciences (DiSCAFF), University of Eastern Piedmont Amedeo Avogadro, Novara, Italy.
J Appl Microbiol. 2006 May;100(5):973-84. doi: 10.1111/j.1365-2672.2006.02846.x.
The purpose of this study was to evaluate the degree of bacterial contamination generated by three Italian composting plants (1, 2 and 3) in two different seasons and to assess the health risk for the employees.
Aerosols samples were collected with an agar impact sampler. Several plant sites and external upwind and downwind controls were examined. Total colony-forming counts of mesophilic and thermophilic bacteria, actinomycetes and streptomycetes, Gram-negatives, coliforms and sulfite-reducers were determined. Selective media were used in order to isolate pathogenic bacteria. The levels of total mesophilic and thermophilic micro-organisms ranged between 33 and >40,000 CFU m(-3) in plant 1, 39 and 18,700 CFU m(-3) in plant 2 and 261 and 6278 CFU m(-3) in plant 3. Strains of Escherichia coli, Staphylococcus aureus and Clostridium perfringens were also found.
The plants monitored in this study have proved to be sources of aerosolized bacteria. The activities involving mechanical movement of the composting mass and the indoor activities were of greatest potential risk. In all the studied plants, a statistically significant dependence was found between the bacterial contamination and the season for some or almost all the analysed parameters, but a clear seasonal trend could not be observed.
This study provides broad evidence of bacterial aerosol dispersion and site-related biological hazards that may be useful to the regional government to implement regulations on worker safety in composting plants.
本研究旨在评估意大利三个堆肥厂（1号、2号和3号）在两个不同季节产生的细菌污染程度，并评估对员工的健康风险。
使用琼脂撞击采样器收集气溶胶样本。对几个厂区以及上风向和下风向的外部对照点进行了检测。测定了嗜温菌、嗜热菌、放线菌、链霉菌、革兰氏阴性菌、大肠菌群和亚硫酸盐还原菌的总菌落形成数。使用选择性培养基分离病原菌。1号厂中嗜温菌和嗜热菌微生物的总数在33至>40,000 CFU/m³之间，2号厂为39至18,700 CFU/m³，3号厂为261至6278 CFU/m³。还发现了大肠杆菌、金黄色葡萄球菌和产气荚膜梭菌菌株。
本研究监测的工厂已被证明是气溶胶化细菌的来源。涉及堆肥物料机械移动的活动和室内活动具有最大的潜在风险。在所有研究的工厂中，对于某些或几乎所有分析参数，细菌污染与季节之间存在统计学上的显著相关性，但未观察到明显的季节性趋势。
本研究提供了细菌气溶胶扩散和与场地相关的生物危害的广泛证据，这可能有助于地区政府实施堆肥厂工人安全法规。
