#COVID-19 can waft through toilets into other apartments, study finds

Scientists now say that the coronavirus may be able to spread throughout buildings, via toilets and drain pipes — an especially alarming prospect for apartment dwellers with suspect plumbing.

The discovery was made in China, after researchers swabbed the “long vacant” apartment directly below a family of five who tested positive for COVID-19. Despite the fact that no one was living in the apartment below, the researchers found traces of the virus on the sink, faucet and shower handle.

This suggested the virus particles potentially wafted from the infected family down the pipes into the vacant apartment, according to the researchers at the Chinese Center for Disease Control and Prevention, which published their findings this month in the journal Environment International.

The researchers cited an experiment that further confirmed their hypothesis. Using a tracer simulator, scientists found infected aerosols in bathrooms up to 12 floors above the family with COVID-19. The researchers believed that the coronavirus-laden aerosols from the family’s feces wafted into their homes through the building’s pipes.

Previous studies have shown that in addition to spreading through respiratory droplets — say, from shouting or coughing — COVID-19 is also present in stool.

And while researchers already knew that coronavirus particles could be thrust into the air with the force of a toilet flush, the new findings are even more troubling for buildings with shared wastewater systems. Often in these systems, gases can rise through the pipes if there isn’t enough water flowing through them, said Lidia Morawska, director of the International Laboratory for Air Quality and Health at Australia’s Queensland University of Technology.

“If there’s smell, it means that somehow air has been transported to where it shouldn’t go,” Morawska, who wasn’t involved in the study, told Bloomberg.

The new findings also track with a notorious case from the 2003 SARS outbreak. At the time, 329 residents of Amoy Gardens apartment complex in Hong Kong all contracted SARS. Researchers believed the building’s faulty sewage pipes — which sent a “virus-laden aerosol plume” through the system — may have been partly to blame.