Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health, Fudan Tyndall Centre, Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
Shanghai Chengtou Sewage Treatment Co., LtD., Shanghai 201203, China.
J Hazard Mater. 2023 Oct 5;459:132234. doi: 10.1016/j.jhazmat.2023.132234. Epub 2023 Aug 6.
Airborne pathogens constitute a growing threat to global public health. Wastewater treatment plants (WWTPs) are important sources of airborne bacteria, which pose great health risks to the employee and nearby residents. In this study, the distribution, transmission and health risk of the airborne culturable and inhalable bacteria carried by PM in a semiunderground WWTP were evaluated. The concentrations of culturable bacteria in the air were 21.2-1431.1 CFU/m, with the main contributions of primary and biological treatments. The relative abundances of culturable and total inhalable bacterial taxa were positively correlated (p < 0.05). However, certain bacteria, including Bacillus, Acinetobacter and Enterococcus, exhibited high reproductive capacity despite their low concentration in the air, suggesting that they can survive and regrow in suitable environments. Transmission modeling revealed that the concentrations of airborne bacteria exponentially decreased with distance from 18.67 to 24.12 copies /m at the source to 0.06-0.14 copies /m at 1000 m downwind. The risks of 8-h exposure in this WWTP except the outlet exceeded the reference value recommended by WHO, which were primarily dependent on P. aeruginosa, Salmonella, and E. coli. Management practices should consider improved controls for bioaerosols in order to reduce the risk of disease transmission.
空气中的病原体对全球公共卫生构成了日益严重的威胁。污水处理厂（WWTP）是空气中细菌的重要来源，这些细菌对员工和附近居民的健康构成了巨大威胁。在这项研究中，评估了半地下 WWTP 中 PM 携带的可培养和可吸入空气中细菌的分布、传播和健康风险。空气中可培养细菌的浓度为 21.2-1431.1 CFU/m，主要来自于一级和生物处理。可培养和总可吸入细菌分类群的相对丰度呈正相关（p < 0.05）。然而，某些细菌，包括芽孢杆菌、不动杆菌和肠球菌，尽管在空气中的浓度较低，但具有较高的繁殖能力，这表明它们可以在合适的环境中存活和再生。传播模型表明，空气中细菌的浓度随距离的增加呈指数下降，从源处的 18.67 到 24.12 个拷贝/m 下降到 1000 米下风处的 0.06-0.14 个拷贝/m。除了出水口之外，该 WWTP 中 8 小时暴露的风险超过了世卫组织推荐的参考值，这主要取决于铜绿假单胞菌、沙门氏菌和大肠杆菌。管理措施应考虑改进对生物气溶胶的控制，以降低疾病传播的风险。
