Beijing, Next time when you visit a public toilet, put the lid down before you flush. A new Chinese study has warned that flushing a toilet generates strong turbulence in the bowl that can expel aerosol particles containing coronavirus out of the bowl which can potentially infect the next bathroom user.

The researchers at the Yangzhou University in China used computer modeling to show how the water from a flushed toilet could spray up into the air as high as three feet.

In a paper published in the journal ‘Physics of Fluids', the team said that it is reasonable to assume that the high-speed airflow will expel aerosol particles from the bowl to regions high in the air above the toilet, allowing viruses to spread indoors causing risks to human health.

"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," said study author Ji-Xiang Wang of Yangzhou University.

Toilets are a daily necessity but also become dangerous if used improperly, especially against the current scenario of a global pandemic.

"Some 40 per cent to 60 per cent of the total number of particles can rise above the toilet seat to cause large-area spread, with the height of these particles reaching 106.5 cm from the ground," wrote the authors.

The data analysis indicates that given the same amount of water and the same gravitational potential energy, annular flushing method causes more virus spread.

"Put the toilet lid down before flushing, which can basically prevent virus transmission," advised the authors.

Clean the toilet seat before using it, since floating virus particles could have settled on its surface.

Wash hands carefully after flushing, since virus particles may be present on the flush button and door handle.

"This paper may also enlighten toilet manufacturers and prompt them to produce better designed toilets in which the lid is automatically put down before flushing and cleaned before and after flushing," said the authors.