Scientists Used Lasers To See How Far Water Droplets Travel From A Toilet Flush

Family bathrooms can get gross, and fast. But it turns out even the most immaculate of bathrooms is not safe from toilet water contamination, as a new study shows.

Scientists used lasers to track how much toilet water is flung from the toilet bowl and into the air during a flush — and the results are pretty gross. When a toilet is flushed, some of the water flings into the air, which the team behind the study described as a “strong chaotic jet.” These droplets, called aerosol plumes, can likely carry pathogens (and plain gross toilet water) into the air.

Aerosol plumes are normally invisible, so the scientists used lasers to track the water droplets in the air.

“Even though we expected to see these particles, we were still surprised by the strength of the jet ejecting the particles from the bowl,” lead scientist and engineering professor John Crimaldi told The Conversation.

“We found that a typical commercial toilet generates a strong upward jet of air with velocities exceeding 6.6 feet per second (2 meters per second), rapidly carrying these particles up to 5 feet (1.5 meters) above the bowl within eight seconds of the start of the flush,” explained Crimaldi.

Previously, scientists would measure the effect of a toilet’s aerosol plume with devices that would sample the air around a flushed toilet. By using lasers, the scientists could see just how far these little droplets traveled throughout the air.

“Toilet bowl water contaminated by feces can have pathogen concentrations that persist after dozens of flushes. But it is still an open question as to whether toilet aerosol plumes present a transmission risk,” Crimaldi noted.

And while scientists used clean water during the experiment, there is a chance that these aerosol plumes could carry pathogens, especially ones that cause respiratory illnesses.

So what can people do to lower the disgusting strong chaotic jet of a flushed toilet? Experts recommend putting down the toilet lid before flushing to lower the chance of poo particles flying all over the place. Cleaning a toilet regularly can also help eliminate potential pathogens from flinging out of the toilet and all over the bathroom.