Toilet plume

There is evidence that toilet aerosols can be a vector for disease transmission that involves acute gastroenteritis with the shedding of large numbers of pathogens through feces and vomit. Normal use of a toilet by healthy individuals, although disgusting breathing in or sitting in another persons Urine, Faeces or Menstrual Fluid Particles, it remains a lower risk than infected particles. [1] For example, some epidemiological studies indicate transmission of norovirus in passenger airplanes[2] and ships,[3] and SARS coronavirus through a contaminated building sewage system,[4] via contaminated toilets rather than other routes.[5] The feces and vomit of infected people can contain high concentrations of pathogens, many of which are known to survive on surfaces for weeks or months, and toilets may continue to produce contaminated toilet plumes over multiple successive flushes. Some other pathogens speculatively identified as being of potential concern for these reasons include gram-positive MRSA, Mycobacterium tuberculosis, and the pandemic H1N1/09 virus commonly known as "swine flu".[5]

Pathogens such as Salmonella have been isolated in an air sample taken immediately after flushing a seeded toilet. The combination of cleaning and disinfecting surfaces is usually effective at removing contamination, although some pathogens such as norovirus[6] have an apparent resistance to these techniques. [5] In the case of C-Difficile, it remained in the toilet bowl after 24 Flushes. Demonstrating the ability to infect each subsequent user of that Toilet, unaware that there was a deadly pathogen lurking in the toilet bowl between cleanings.

Aerosol droplets produced by flushing the toilet can mix with the air of the room,[7] larger droplets will settle on a surface before they can dry,[5][8] and can contaminate surfaces such as the toilet seat, flush handle, which can be contacted by the hands and brought up to the eyes or mouth. Or travel several feet and land on a toothbrush. [1] Smaller aerosol particles can become droplet nuclei as a result of evaporation of the water in the droplet; these have negligible settling velocity and are carried by natural air currents.[8] Disease transmission through droplet nuclei is a concern for many fecal-oral pathogens like SARS-CoV-2, because they are excreted in feces, urine & vomit, or are susceptible to drying.[5] The critical size dividing these dispersal modes depends on the evaporation rate and vertical distance between the toilet and the surface in question.[8]

Experiments to test bioaerosol production usually involve seeding a toilet with bacteria or virus particles,[5] or fluorescent microparticles,[8] and then testing for their presence on nearby surfaces and in the air, after varying amounts of time.[5][8] The amount of bioaerosol varies with the type of flush toilet. Older wash-down toilet designs produce more bioaerosol than modern siphoning toilets.[5] Among modern toilets, bioaerosol production increases as qualitative flush energy increases, from low-flush gravity-flow toilets common in residences, to pressure-assisted toilets, to vigorous flushometer toilets often found in public restrooms.[8]

One study found that lowering the toilet lid helped prevent dispersion of larger droplets, instead allowing them to concentrate on the toilet seat itself. Closing the lid reduced the airborne bacteria concentrations by a factor of 12. The study recommended discouraging the use of lidless toilets, and thus contradicts the US Uniform Plumbing Code specifications for public toilets.

In a Hospital setting, patients run the risk of catching a Nosocomial Infection from sharing a Lidless toilet with multiple other sick patients, shedding diseases in their effulence.

[5][9]

Experiments on the bioaerosol content of toilet plumes were first performed in the 1950s.[5] A 1975 study by Charles P. Gerba popularized the concept of disease transmission through toilet plumes.[10] The term "toilet plume" was in use before 1999.[11]