Scientists know that coronaviruses, including the SARS-CoV-2 virus responsible for the COVID-19 pandemic, can remain infectious for days — or even longer — in sewage and drinking water.
Two researchers, Haizhou Liu, an associate professor of chemical and environmental engineering at the University of California, Riverside; and Professor Vincenzo Naddeo, director of the Sanitary Environmental Engineering Division at the University of Salerno, have called for more testing to determine whether water treatment methods are effective in killing SARS-CoV-19 and coronaviruses in general.
The virus can be transported in microscopic water droplets, or aerosols, which enter the air through evaporation or spray, the researchers wrote in an editorial for Environmental Science: Water Research & Technology, a leading environmental journal of the Royal Society of Chemistry in the United Kingdom.
Previous studies have shown that coronaviruses exist and can maintain their viability in sewage and hospital wastewater, originating from the fecal discharge of infected patients. Growing attention to this issue is also supported by studies highlighting the persistence of these viruses in aquatic environments and wastewater treatment plants. Therefore, the SARS-CoV-2 virus may already be present in wastewater.
The novel coronavirus could also colonize biofilms that line drinking water systems, making showerheads a possible source of aerosolized transmission. This transmission pathway is thought to be a major source of exposure to the bacteria that causes Legionnaire’s disease, for example.
The extent to which viruses can colonize biofilms is also not yet known. Biofilms are thin, slimy bacterial growths that line the pipes of many aging drinking water systems. Better monitoring of coronaviruses in biofilms might be necessary to prevent outbreaks.