Toilet flushing can spread coronavirus faster in air, says report

The next time you flush your toilet, close the lid. A recent study by researchers at Yangzhou University in China claims the novel coronavirus can survive in the human digestive tract and appear in faeces of the infected, news agency Press Trust of India reported on Wednesday.

The study, published in the journal Physics of Fluids, used computer models to simulate water and air flows in a flushing toilet and the resulting droplet cloud. This, scientists often refer to as “toilet plume aerosol”.

Flushing creates a great deal of turbulence and tiny bits of faecalmatter, which the naked eye can’t see.This can be thrown into the air and can stick to aerosols and settle on the surroundings so anyone visiting the toilet next time can breathe it.

‘Flushing will lift the virus up from the toilet bowl,’ co-author of the paper Ji-Xiang Wang, who researches fluids at Yangzhou University, said in an email, according to Washington Post. Wang further said that people ‘need to close the lid first and then trigger the flushing process.’

The novel coronavirus has been found in the feces of Covid-19 patients, but it remains unknown whether such clouds could contain enough virus to infect a person.

The researchers show how the water from a flushed toilet could spray up into the air as high as three feet, reported New York Daily News.

‘One can foresee that the velocity will be even higher when a toilet is used frequently, such as in the case of a family toilet during a busy time or a public toilet serving a densely populated area,’ Wang said.

Public toilets are known spreaders of viruses transmitted via ingestion but it has not been proved that it also causes the spread of COVID-19. The role of toilets in the transmission of respiratory viruses has not been established, Charles P Gerba, a microbiologist at the University of Arizona told the Washington Post.

‘The risk is not zero, but how great a risk it is, we don’t know,’Gerba, an expert in the field for 45 years, said. ‘The big unknown is how much virus is infectious in the toilet when you flush it…and how much virus does it take to cause an infection,’ he added.

Bryan Bzdek, research fellow at the University of Bristol, who was not involved in the study, told the PTI, ‘Even if the virus were contained in the produced aerosols, it is unknown whether the virus would still be infectious, there is not yet clear evidence for faecal-oral transmission.’