Possibility and Risk of COVID-19 Virus Transport via Bioaerosols in Building Plumbing and Municipal Drainage Systems

最近的研究报告称，COVID-19病毒（SARS-CoV-2）可以通过约10微米大小的小型生物气溶胶传播。这些生物气溶胶可以在更长的时间内保持悬浮状态，而病毒在雾化后仍具有感染性许多小时。此外，在感染者的粪便中也检测到了SARS-CoV-2。因此，迫切需要研究建筑管道和城市污水系统中载病毒气溶胶的产生和传输，评估暴露风险，并制定各种风险缓解策略。在这项研究中，阿尔伯塔大学（水力/环境工程，化学材料工程和公共卫生）的五名研究人员建议与市政当局（埃德蒙顿，卡尔加里和红鹿），阿尔伯塔环境和公园以及领先的咨询公司（Stantec）合作，调查建筑管道和市政排水系统中病毒负载生物气溶胶的产生，运输和命运。拟议的研究将进行实验室实验，以调查在建筑物管道和排水系统的各种系统配置和操作条件下气溶胶的产生，运输和命运。进一步的研究将涉及选择合适的SARS-CoV-2替代物，并在二级生物安全实验室的小规模模型中研究其雾化效率和灭活率。还将对生物气溶胶进行定性暴露评估，以确定潜在的结构/操作改进，以缓解风险。拟议的研究将解决我们的合作伙伴面临的关键问题：SARS-CoV-2能否在建筑管道和排水系统中作为生物气溶胶传播，暴露风险水平是什么，以及如何采取适当的预防措施/缓解策略来减少职业和公共卫生风险。该研究还将为以下长期需求提供坚实的基础：1）提高对基于废水的流行病学的理解，以早期发现冠状病毒和肠道病原体;以及2）改善我们的废水基础设施的设计和运营，并降低病毒暴露和传播的风险。

Recent studies reported that COVID-19 virus (SARS-CoV-2) can be transmitted through small bioaerosols of about 10 micrometre in size. These bioaerosols can remain suspended for longer periods of time with virus remaining infective for many hours after aerosolization. In addition, SARS-CoV-2 has been detected in feces from infected people. Therefore, there is an urgent need to study the generation and transport of virus-laden aerosols in building plumbing and municipal wastewater systems, to assess exposure risk, and to develop various risk mitigation strategies. In this study, five researchers at the University of Alberta (hydraulic/environmental engineering, chemical materials engineering and public health) propose to investigate the generation, transport and fate of virus laden bioaerosols in building plumbing and municipal drainage systems, in partnership with the municipalities (Edmonton, Calgary and Red Deer), Alberta Environment and Park, and a leading consulting company (Stantec). The proposed research will conduct lab experiments to investigate the generation, transport and fate of aerosols under various system configurations and operation conditions in building plumbing and drainage systems. Additional study will involve the selection of proper surrogates for SARS-CoV-2, and investigate their aerosolization efficiency and inactivation rate in a small-scaled model placed in a Level-2 biosafety lab. A qualitative exposure assessment of bioaerosols will also be conducted to identify potential structural/operation improvements for risk mitigations. The proposed research will address key questions facing our partners: can SARS-CoV-2 be transported as bioaerosols in building plumbing and drainage systems, what is the exposure risk level, and what are the proper precautions / mitigation strategies to reduce occupational and public health risks. The study will also provide a solid foundation for the long-term needs of: 1) improving the understanding of wastewater based epidemiology for early detection of coronavirus and enteric pathogens; and 2) improving the design and operation of our wastewater infrastructure and to mitigate the risk of viral exposure and transmission.