SARS-CoV-2 infectivity potential in municipal wastewater: Implications for public health & water treatment
Abstract
The COVID-19 pandemic has emphasized the importance of wastewater surveillance to monitor the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Increased surveillance requires attention to municipal workers who collect and handle samples at treatment facilities. While SARS-CoV-2 is primarily transmitted through respiratory droplets, evidence suggests virus can be transmitted via fecal-oral route and contaminated environmental samples, including municipal wastewater. This project investigated SARS-CoV-2 infectivity in wastewater and assessed potential risks to municipal workers and all those in contact with wastewater. Vero E6 infectivity assays determined inactivation kinetics of SARS-CoV-2 in time and temperature-based assays, aerosolization assays, and UV disinfection studies. Stability in infectivity was observed in 23, 15 and 4oC spiked samples with longer viral survival observed at colder temperatures. SARS-CoV-2 in wastewater aerosols was infectious directly to Vero E6 cells and also maintained infectivity in aerosolized droplets settling on various materials such as plastic and stainless-steel. The log reduction kinetics were also defined using collimated-beam UV irradiations to determine the optimal UV dosage for viral inactivation. Understanding SARS-CoV-2 infectivity in the wastewater treatment process is essential to inform public health by providing crucial information on risks associated with handling wastewater to prevent community spread.