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