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I've heard claims of airborne poop particles that fly into the air everytime one flushes a toilet. Here's some examples:

  • HERE someone states that flushing the toilet "aerosolizes" water/poop into the air
  • HERE is another article referencing such high flying particles
  • HERE is a WebMD article featuring the same

The central quote from the last two is from Charles Gerba, PhD, a professor of microbiology at University of Arizona in Tucson:

Polluted water vapor erupts out of the flushing toilet bowl and it can take several hours for these particles to finally settle — not to mention where.

Similarly, I've heard that hand dryers spew these particles out onto one's hands.

  • HERE is an example of a claim like that
  • HERE is a short forum discussion about the same

True? Worrisome? Also, I'd love any references as to the method of making the particles airborne if they do occur. I had the understanding that to aerosolize, one needed to overcome the cohesive forces of the material -- hence forcing them apart into small particles via strong jets of air vs. the nominal droplet size of the liquid.

I'm skeptical that a toilets have the power necessary to aerosolize, except for perhaps the "jet-powered" public toilets.

Oddthinking
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Hendy
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    Be aware that there are many different toilet designs, and the popular designs in North America (e.g. siphoning) are not used everywhere (see: http://en.wikipedia.org/wiki/Flush_toilet). Non-siphoning designs appear to have more forceful water-splashing. – Oddthinking Jun 07 '11 at 02:31
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    See also http://skeptics.stackexchange.com/questions/3202/is-it-more-hygenic-to-keep-the-lid-down-on-the-toilet-after-use – Oddthinking Jun 07 '11 at 02:32
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    If you can smell it, then this means that chemicals from the poop are reaching your nose. They have to get there somehow... – Lagerbaer Jun 07 '11 at 04:39
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    @lagerbaer scientifically one must presuppose that if it can be smelt, it has indeed been dealt. – Monkey Tuesday Jun 07 '11 at 05:27
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    "There's poo everywhere. What are we gonna do!?" - Bacteria are normal. Get over it. :-) – Lennart Regebro Jun 07 '11 at 06:07
  • @Lagerbaer: Your reasoning is second to none. If I had the connections I'd nominate you for an Ig Nobel in talking sh|t. –  Jun 07 '11 at 10:10
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    @Lagerbaer: Chemicals from it are reaching your nose, but that doesn't imply anything about bacteria or particulate matter. It's a bit like equating smelling food and eating it. – Mr. Shiny and New 安宇 Aug 26 '11 at 12:56

2 Answers2

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Mythbuster Episode 11 of 2004 Series showed that fecal matter did seem to get everywhere, and the explanation appeared to be through aerosol, or at least flung out of the toilet somehow.

Jamiec
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Rory Alsop
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    The link to the video is gone, but I assume it is this one: https://en.wikipedia.org/wiki/MythBusters_(2004_season)#Toothbrush_Surprise – StasM Nov 20 '13 at 00:40
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    Mythbusters a credible source, that is new :) – Andra May 17 '14 at 12:04
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    @Andra Their experiments were a bit rough-and-ready, but they were generally scientific and they showed their working. If their experiment found fecal matter being distributed around the bathroom, then yes, thats pretty credible. Of course I'd prefer a peer-reviewed publication. – Paul Johnson Dec 31 '20 at 09:07
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This subject received a lot of attention during the COVID-19 pandemic of 2020. For example, a NY Times article discusses the so-called "toilet plume":

Scientists have found that in addition to clearing out whatever business you’ve left behind, flushing a toilet can generate a cloud of aerosol droplets that rises nearly three feet. Those droplets may linger in the air long enough to be inhaled by a shared toilet’s next user, or land on surfaces in the bathroom.

This toilet plume isn’t just gross. In simulations, it can carry infectious coronavirus particles that are already present in the surrounding air or recently shed in a person’s stool. The research, published Tuesday in the journal Physics of Fluids, adds to growing evidence that the coronavirus can be passed not only through respiratory droplets, but through virus-laden feces, too.

It also discusses the mechanism by which the aerosolized fecal matter occurs:

A computer simulation of the toilet flushing mechanism showed that when water pours into the toilet and generates a vortex, it displaces air in the bowl. These vortices move upward and the centrifugal force pushes out about 6,000 tiny droplets and even tinier aerosol particles.

Depending on the number of inlets in the toilet, flushing can force anywhere from 40 to 60 percent of the produced aerosols high above the seat.

pacoverflow
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  • I suppose there's rarely any point in discussing the Stack Exchange scores. But can anyone explain why the one answer got a score of 13 with very little explanation and comments that the one cited source is unreliable and the link goes nowhere; while this second answer quotes scientific analysis from the New York Times, with good links, and earned a score of 0? – Chaim Dec 31 '20 at 18:46
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    @Chaim: One has been gathering votes for 9 years (during much of which the link probably worked). The other is two days old. – Oddthinking Jan 01 '21 at 08:27
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    @Oddthinking Yeah, when I posted the comment yesterday I had not noticed the timing. I agree that timing explains a lot. I think, though, that this is an important, inherent problem in the Stack Exchange method of scoring questions and answers, almost necessarily creating and a disconnect between scores and actual merit. – Chaim Jan 01 '21 at 14:13