Drinking water and sewage could spread Covid-19.
8 April 2020
Researchers have called for more testing to determine if water treatment methods are effective in killing the SARS-CoV-19 and coronaviruses in general.
Haizhou Liu, an associate professor in chemical and environmental engineering at the University of California Riverside, US and Professor Vincenzo Naddeo, director of the Sanitary Environment Engineering Division at the University of Salerno, Italy, propose that the virus can be transported in microscopic water droplets, or aerosols, which enter the air through evaporation or spray. They highlight a sewage leak in Hong Kong during the 2003 SARS outbreak that caused a cluster of cases through aerosolisation. Though no known cases of Covid-19 have been caused by sewage leaks, the novel coronavirus is closely related to the virus that caused SARS and infection via this route could be possible. Their research is published in the journal Environmental Science: Water Research & Technology.
The researchers also propose that the novel coronavirus might colonise biofilms, the coating formed on the inside of water pipes, making shower heads a possible source of aerosolised transmission. This particular pathway is believed to be a source of exposure to the bacteria that causes Legionnaires disease. The extent to which viruses can colonise biofilms is not yet known.
However, the researchers point out that fortunately, most water treatment routines are thought to kill or remove coronaviruses effectively in both drinking and wastewater. Oxidation with hypochlorous acid or peracetic acid and inactivation by UV irradiation, as well as chlorine are thought to kill coronaviruses. But the researchers warn that these methods have not been studied for effectiveness specifically on SARS-CoV-19.
The researchers add that developing countries and some regions within highly developed nations which lack the basic infrastructure to remove other common contaminants from water, might not be able to remove SARS-CoV-19 either. These locations may experience frequent Covid-19 outbreaks that spread easily through globalised trade and travel.
Environmental Science: Water Research & Technology DOI:10.1039/D0EW90015J