“Out of sight, out of mind” – an expression we all know, but a luxury we cannot exercise when it comes to microbial pathogens. Until recently, the effects of toilet flushing were not visible and thus, ignored, but a study published in Scientific Reports changes that.
The image above is from a study led by Professor John Crimaldi, head of the Ecological Fluid Dynamics Lab at the University of Colorado Boulder. Crimaldi and his team of engineers analyzed the visible suspension of fecal particles and hazardous pathogens that spread when flushing a toilet.
Researchers used a commercial toilet with no lid, the common toilet in businesses, hospitals, and various public settings. Each flush created a ~1.5 meter plume. The larger droplets landed and settled quickly, but particles < 5 μm remained airborne, visible with a neon green light. The unique green light gives insights to the physics and kinematics of the aerosolized particles emitted from a flush, particles that carry pathogens like E. coli, C. diff, coronavirus, norovirus, and adenovirus. Understanding how suspended particles behave encourages novel disinfection or ventilation methods to minimize infection.