Op-ed: How toilets can spread COVID—and what to do about it

Toilets may be an important source of COVID-19 spread, according to Joseph Allen, associate professor of exposure assessment science at Harvard T.H. Chan School of Public Health.

In a September 1, 2020 op-ed in the Washington Post, Allen wrote that the coronavirus can be detected in stool samples, and the churning and bubbling of water when a toiled is flushed aerosolizes fecal matter, creating particles that will float in the air.

“Let’s be clear,” said Allen. “When you flush the toilet, you’re breathing in toilet water, and whatever is in that toilet water—including viruses and bacteria.” These “bioaerosols” can also spread around the room, linger in the air, and settle onto surfaces in the bathroom, creating the potential for transmission.

Allen highlighted several actions people can take to help protect themselves. He recommended increasing ventilation in bathrooms by turning on the exhaust fan when you enter, leaving it on when you’re done, and opening any windows. He also said to be sure to close the lid when you flush the toilet, clean and disinfect bathroom surfaces, and wash your hands vigorously after using the bathroom.

Perhaps most important, said Allen, is to trust your nose. If the bathroom smells bad, wait to let the room air out a bit before you go in.

Read the Washington Post op-ed: It’s time to talk about how toilets may be spreading covid-19