Ew! This is What Happens When You Flush the Toilet
Videos reveal an invisible plume of droplets, capable of packing infectious pathogens, shooting out ‘like a rocket’ and drifting to the ceiling
When you flush a toilet with the lid up, water droplets too small to see—and potentially packed with infectious viruses or bacteria lingering in the bowl from a previous pooper—woosh into a plume that stays airborne for minutes and spreads across the bathroom, new videos reveal.
Scientists have known for years that a flushed toilet or urinal can generate a plume of potentially infectious aerosols, based on computer modeling of fluid dynamics or by using special devices to detect the invisible particles at select locations.
The new experiment, using green lasers in a lab, is the first to directly visualize what happens and measure the plume’s velocity and extent. The resulting videos — two of them below — might just make you rethink bathroom hygiene. The first one shows what’s visible under normal light (left) and with the lasers:
