Keep a lid on it: Flushing a toilet may spread Covid-19

  • We know that public restrooms can be hot spots for germs, and as it turns out, Covid-19 may be lurking there as well
  • It's known that viral particles may be present in stools, which can shoot up into the air when flushing
  • New, safer toilet designs and stricter hygiene measures are recommended for the future

As we wash our hands, wear our masks and practise physical distancing in an attempt not to get infected with Covid-19, there might be another factor we aren't taking into account – public toilets.

Ever heard of the phenomenon called the “toilet plume”, where germs are ejected several metres into the air when you flush the toilet with the lid up? Turns out, there might be a chance that SARS-CoV-2, the virus that causes Covid-19, can also travel in this plume of aerosol droplets.

Scientists have found that coronavirus particles that may already be present in a person’s stool, can be shot up in the air through aerosol droplets when flushing, too. The research was published on 16 June 2020 in the journal Physics of Fluids.

Faeces and coronavirus

According to the researchers, transmission through the faecal-oral route is common for many viruses, including SARS-CoV-2.

At the beginning of the Covid-19 outbreak in January 2020, it was believed that this mainly respiratory virus could only spread through respiratory droplets transported by a cough or sneeze from a person who is already sick.

But as more research emerged and we started discovering more about this relentless virus, it turns out that SARS-CoV-2 can infect more than only the cells in the lungs – it can be present in the gastrointestinal tract, too. Earlier research suggested that viral particles may be shed in the stools of a sick person.

It’s all in the flush

This latest study took things a step further and suggested that the trajectories of the aerosol particles during toilet flushing can also play a part in transmission. The researchers did a simulation to mimic two similar flushing processes used commonly in toilets around the world. The simulation showed that as much as 40% to 60% of the viral particles shed in faeces can be propelled up into the air, reaching far above the toilet seat.

These particles can then hover in the air and be inhaled. It's not exactly sure how potent these viral particles are and how likely it is that you will get infected when using the same restroom as a person with Covid-19, but the possibility exists, as even after flushing, the particles can remain in the air for a while.

Safer toilet behaviour and better toilet design

As we approach a new normal, the researchers suggest the following tips to reduce your risk of being infected with Covid-19, especially when using a public restroom or sharing a house with someone who is recovering from mild Covid-19:

  • Always close the toilet lid before flushing. This doesn’t only limit your risk of Covid-19 infection, but also reduces contact with other bacteria and viral particles.
  • Clean the toilet surface before using it, as the floating viral particles may drop back down and settle on the surface, especially in a small, poorly ventilated bathroom.
  • Always wash your hands thoroughly after flushing.

The researchers said that their study may also prompt manufacturers to rethink the design of toilets in the future. Imagine lids closing down automatically before you flush, and flush mechanisms you don’t operate with your hands? Not only might this curb the spread of Covid-19, but will also contribute to overall hygiene and disease control in general.

READ | Research reveals why you shouldn't overlook the gastro symptoms of the new coronavirus

READ | Worried about catching coronavirus from surfaces? The city you live in may matter

READ | Breathing and talking contributes to coronavirus spread, study finds

Image credit: Vie from Pexels

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