Department of Architecture and Civil Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
Department of Architecture and Civil Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
J Hazard Mater. 2018 Sep 15;358:389-396. doi: 10.1016/j.jhazmat.2018.07.003. Epub 2018 Jul 3.
The process of toilet-flushing can generate flushing-associated water droplets which can potentially expose humans to pathogen-laden aerosols. Very little is known about such aerosol dissemination or the means for minimizing exposure to these aerosols. This study has evaluated the efficacy of ultraviolet waveband C (UV-C) for disinfection of flushing-generated pathogen-laden aerosols through tests with localized disinfection systems for airborne and surface contaminations. Three types of bacteria were chosen for investigation: Staphylococcus epidermidis, Escherichia coli, and Salmonella typhimurium. Tests were conducted with UV-C tubes of 5 W and 10 W. High levels of disinfection efficacies were observed, ranging from 76% to 97% for bacteria-laden aerosols at sources of emission, and efficiencies of 53% to 79% for surface samples in localized systems. The results from the localized systems were further compared with those obtained with an upper-room ultraviolet germicidal irradiation (UVGI) system. As it is important to note, the UV-C doses and ozone emissions for the localized systems were found well below the limits recommended in current guidelines. This research has shown that the disinfection of flushing-generated pathogen-laden aerosols in proximity to the source of emission was more effective than at the more distant sites where aerosols may be dispersed to the environment.
冲厕过程会产生冲水相关的水滴，这些水滴可能会使人类接触到带有病原体的气溶胶。对于这种气溶胶的传播方式，以及如何最大限度地减少接触这些气溶胶的方法，我们知之甚少。本研究通过对空气传播和表面污染的局部消毒系统进行测试，评估了紫外线波段 C（UV-C）对冲洗产生的带病原体气溶胶进行消毒的效果。选择了三种细菌进行研究：表皮葡萄球菌、大肠杆菌和鼠伤寒沙门氏菌。使用 5W 和 10W 的紫外线灯管进行了测试。在污染源处，对携带细菌的气溶胶进行了测试，观察到了高水平的消毒效果，范围在 76%至 97%之间，在局部系统中的表面样本的效率为 53%至 79%。局部系统的结果与上室紫外线杀菌辐照（UVGI）系统的结果进行了比较。需要注意的是，局部系统的紫外线剂量和臭氧排放量远低于现行指南中推荐的限值。本研究表明，在污染源附近对冲洗产生的带病原体气溶胶进行消毒比在更远的地方更有效，因为气溶胶可能会扩散到环境中。
