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What comes up when you flush (colorado.edu)
168 points by sciencefreak939 on Dec 8, 2022 | hide | past | favorite | 195 comments



This is very interesting but I'm curious why the researchers chose to focus on pressurized commercial toilets as apposed to the non-pressurized, gravity-fed residential toilets that most of us[0] likely use far more frequently.

[0] I admit, I might be showing my US based western bias here; I'm not sure.


The people you share your home toilet with are bound to spread any pathogens they're carrying to you in multiple way. You are likely touching the same things, eating the same things, touching them, kissing them, etc. A public toilet may be used by hundreds of people each day and is the single common point of contact and thus carries more potential for spread of pathogen


But the pathogens your genetically close relatives carry, are ones they did not shrug off, and are probably better suited to stick around you too.

(Just a thought, loads of holes in it, but it may be true in some edge cases.)


You probably share enough other contact with such people that you will get what they have anyway.


In fact it would be interested to compare all sorts of toilets under this aspect. Perhaps there is one that is superior.

On the other hand it's interesting not just to see water particles flying through the room but perhaps also where they are coming from. If you design a toilet that sucks everything out first (without a splash) and the rapidly replenishes the water (in a splashy fashion), the percentage of pathogens might be much lower.


In the US, commercial toilets like the one tested do not have lids. Probably for ease of maintenance and (most likely) a misguided notion that not having a lid is more hygienic and easier to clean. These are toilets found in office buildings, shopping centers, airports, etc.

Anybody know if commercial toilets in UK and EU tend to have lids?


Not sure about UK but EU at least tends to have fully enclosed stalls (no gaps above, below, or between the partitions) in public restrooms which should hopefully reduce aerosol spread.


In the UK we usually have lids, unless it's been vandalised.


In France, I generally don't see lids on public toilets. In fact, its pretty common to see toilets without seats---vandalized or perhaps removed for maintenance, I'm not sure. (Maybe someone French has an idea why the seats are often missing/removed?)


It's actually cultural, lid and seat presence varies all over the world.

Prepare to be amazed:

Toilets of the World

https://toilet-guru.com/

https://news.ycombinator.com/item?id=20505602

(2019; 266 points, 190 comments)

For example, in some places this is normal and acceptable / desirable: https://toilet-guru.com/pictures/greece-kastraki-dscf1764.jp...


> In fact it would be interested to compare all sorts of toilets under this aspect. Perhaps there is one that is superior.

You could also just close the lid before you flush?


You can, but closing the lid doesn't seal anything.


If you put the lid down before you flush to protect yourself from all the dirtiness, doesn’t that mean the lid (which you have to touch to put up/down) is itself extremely dirty?


> If you put the lid down before you flush to protect yourself from all the dirtiness, doesn’t that mean the lid (which you have to touch to put up/down) is itself extremely dirty?

The parts of the lid that you touch to raise and lower it are probably relatively distant from the parts of the lid that would receive the brunt of any splashback.


The part I touch to lower is the top of the lid, so relatively distant. But the part I touch to raise is the underside of the lid, at the edge. While it might not be in the most direct line-of-fire, I would expect it would actually get a decent amount of particles because it is adjacent to an air gap, where pressure would escape. But I'm no aerodynamicist — just speculating!


Why would you touch the underside of the lid to raise the it? You can't even reach the underside properly before you've opened the lid.

In any case, just use a piece of toilet paper to touch the lid, if you are concerned.


Most of the spray will hit the broad inside of the lid.

When you move the lid, you only touch the outer rim at one or two places.

You can use a bit of toilet paper to protect your hands, and wash them afterwards, too.


Remember to wash your hands.


That works as long as you don't touch anything after opening the lid, before washing. Like your phone, for example.


Or the door


There are no lids on squat toilets.


Lids must remain up always. For family peace, I removed the lid completely.


What?

How's using the lid a controversial thing at all?


The commenter is likely snarking about living with a female (or females). Some can be, er, particular about the toilet lid.

(Yes, the solution here is to put the lid back up when done, but then that ruins a bit of the GP's (I think) intended humor.)


Some men are learning to urinate sitting down. Think about it, if that toilet is sending aerosols into the air, what is your stream of urine doing as you stand distantly from the toilet? Also, if you've ever cleaned toilets then you know about the accuracy of anyone who insists on standing.

https://www.theunconventionalroute.com/men-pee-sitting-down/ or just search using terms like: men are learning to pee sitting down


I piss sitting down plenty and always have (sometimes I just want to sit and relax a bit, you know? Or sometimes you feel like you've got a fart in the mix but aren't entirely sure it won't be a shart, so you sit just to be safe) but I do find it doesn't quite empty me out as well. Standing's better, like, anatomically, for some reason.


Studies have shown that there is no difference for healthy adult males, but sitting is actually better for evacuation as you start to get an enlarged prostate (Roughly half of men over 50).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4106761/


Lovely, maybe I'm getting one of those way younger than I'm "supposed" to, LOL. I think the first time I noticed a (small, but non-zero) difference between the two was in my late 20s.


You still splash when sitting. You'd need to measure it to know what results in less aerosol exposure (particularly considering the distance-to-face factor), even though it probably doesn't matter anyway. And anyone who has ever cleaned toilets knows that the women's room is not a paradise of cleanliness.


You're thinking of the seat, not the lid. Although women are wrong about this. The standard should be a single seat manipulation per urinary event. That's the only fair way to do it. Why should the men manipulate the seat twice and women never?


If your goal is to minimize pathogens transferred from seat to hand, you can think of the man's second seat manipulation as "zero cost" in the sense that their hand is already contaminated and they'll need to wash thoroughly

Man 2x, Woman 0x = 1 "contamination" cost incurred Man 1x, Woman 1x = 2 "contamination" cost incurred


This is an interesting view. Like anything else it's important to establish what the goals actually are.


Agreed, lid goes down prior to each flush. Guys raise the seat if they are standing up, otherwise anyone else using the toilet just needs to raise and lower the lid.


Yeah, this has long been my response to the stupid seat-up/seat-down controversy. Fine, lid's going down too. That way stuff can't get knocked or dropped in, and it reduces flush-spray, so it's better anyway.


No, two of the relationships I’ve been in have involved women who absolutely loathed if the lid was down, or if the seat was up. It had to be lid-up, seat-down at all times.


I had to teach my (female) partner to close the lid, too. She got it after a while.


Huh? You open the thing, sit down to do your business, then close it. It's two simple manipulations for everyone, and for civility.


Why do you want an open air toilet?

Just like rules are there to be followed, the lid is there to be closed. Ordnung muss sein.


Yes rules must be adhered to, and removing the lid ensures compliance with correct rules.


Toilets on trains (at least in Germany) work that way. Presumably because it cuts down on the amount of water necessary to flush, but may have other benefits as well.


...as do the facilities on commercial airplanes.


If you travel a lot in the US, you can go weeks without using a toilet with a lid. Many/most midrange business-focused hotels have commercial style lidless toilets, and save for custom Toto washlet boutique office setups demanded by Americans who have had the pleasure of spending time in asia, almost no commercial office or workspace in the US has lidded toilets.


> If you travel a lot in the US, you can go weeks without using a toilet with a lid.

“Achievement unlocked”


Commercial toilets are designed or engineered, but evidently not very well.

And they never have a lid you can close to avoid the spray.


Commercial toilets are amazing in Japan, they usually do have lids.

"In Japan, these high-tech toilets are everywhere: hotels, restaurants, bus stations, rest stops and around 80% of homes."

https://www.npr.org/sections/money/2020/02/25/808791622/why-...

The quote is somewhat exaggerated but mostly true. I've even found the public toilets to be incredibly clean. While it is possible to occasionally find older porcelain squat toilets they are becoming very rare.

https://www.bing.com/images/search?q=public+toilets+in+japan


Or you get a squatter toilette. Also you need to bring your own paper for a lot of public toilettes. Though it has been almost 20 years since I last visited. At the time I wondered why they handed out so many advertising Kleenex travel size packs. It was for the train station bathroom.


I think squat pots are anatomically better than simply sitting.


Oh, that's just American weirdness. Toilets in most of the rest of the world are saner. They also typically have a proper seat, instead of the U shape required by law in many places in the US.


That's required by law? I thought it was just a cost saving measure (like everything else about US...Everything)

What's the purpose?


It’s included by reference as part of the universal plumbing code. There isn’t a “toilet seat act of 1927” or something.

The original intent was to make it easier for women to clean the perineal area without contacting a surface, and reduces genital contact with a surface.

How do I know this? My wife was on a safety committee in a past job where there was a workplace injury claim related to this topic. In our case, there was an automated toilet cover dispenser, which made the round seat code compliant.


> It’s included by reference as part of the universal plumbing code. There isn’t a “toilet seat act of 1927” or something.

Yes. But that standard is being enforced by laws (and perhaps other legal mechanisms) in many places in the US. See https://en.wikipedia.org/wiki/Uniform_Plumbing_Code


I believe it's mostly a matter of hygiene, less contact area for your genitals.


> Toilets in most of the rest of the world are saner. They also typically have a proper seat

Rest of the world? What about the places with squat toilets? Those are common in many places in the "rest of the world", and they don't even have seats!


Pooping while squatting is healthier, so maybe that qualifies as saner too.


It's also just, really damn effective. If you are ever having trouble squeezing one out on our antiquated and stupidly un-designed porcelain throne, get your legs higher so you are closer to squatting, and consider investing in a stool to put your feet on.


If you read carefully, you will notice that I wrote 'most of the rest of the world' exactly because of those caveats.

Here in Singapore we have both styles of toilets.


The rest of the world also has no problem with bidets, here in the US we prefer smearing it around with paper like peanut butter until it’s good enough


That’s pretty much standard in all western countries I’ve visited.


Speak for yourself, my family is buying bidets for 7 or 8 other families. We have two.


They are very popular in Singapore, too. Though very different from what eg the Japanese have.


The last time I saw a serious study on the issue, which did include lid testing, the lid did little to stop the spray. It just blows out from the sides under the seat.


Clearly we need over engineered toilet lids that seal all around with double locks.

Or perhaps even if they do spray in all directions it's not quite as horrible as it's made out to be.


Probably with one way valves so they can flush despite the seal. I agree with the idea that it is probably not a big deal. Good for headlines grossing people out, but probably a non-issue for average humans with functioning immune systems.


I mean those commercial toilets are what you'll find in a lot of office environments, schools, stores, etc etc. And it's the time when you're likely present in a room for someone else's flush. And, you also have no idea of who's using it. In a household, one will probably have an okay sense if someone else is sick (eg flu).


According to Slavoj Žižek, Germans love Hermeneutic stool diagnostics.

>Žižek on toilets. Slavoj Žižek during an architecture congress in Pamplona, Spain.

>The German toilets, the old kind -- now they are disappearing, but you still find them. It's the opposite. The hole is in front, so that when you produce excrement, they are displayed in the back, they don't disappear in water. This is the German ritual, you know? Use it every morning. Sniff, inspect your shits for traces of illness. It's high Hermeneutic. I think the original meaning of Hermeneutic may be this.

https://en.wikipedia.org/wiki/Hermeneutics

>Hermeneutics (/ˌhɜːrməˈnjuːtɪks/)[1] is the theory and methodology of interpretation, especially the interpretation of biblical texts, wisdom literature, and philosophical texts. Hermeneutics is more than interpretive principles or methods we resort to when immediate comprehension fails. Rather, hermeneutics is the art of understanding and of making oneself understood.

>“In a traditional German toilet, the hole into which shit disappears after we flush is right at the front, so that shit is first laid out for us to sniff and inspect for traces of illness. In the typical French toilet, on the contrary, the hole is at the back, i.e. shit is supposed to disappear as quickly as possible. Finally, the American (Anglo-Saxon) toilet presents a synthesis, a mediation between these opposites: the toilet basin is full of water, so that the shit floats in it, visible, but not to be inspected. [...] It is clear that none of these versions can be accounted for in purely utilitarian terms: each involves a certain ideological perception of how the subject should relate to excrement. Hegel was among the first to see in the geographical triad of Germany, France and England an expression of three different existential attitudes: reflective thoroughness (German), revolutionary hastiness (French), utilitarian pragmatism (English). In political terms, this triad can be read as German conservatism, French revolutionary radicalism and English liberalism. [...] The point about toilets is that they enable us not only to discern this triad in the most intimate domain, but also to identify its underlying mechanism in the three different attitudes towards excremental excess: an ambiguous contemplative fascination; a wish to get rid of it as fast as possible; a pragmatic decision to treat it as ordinary and dispose of it in an appropriate way. It is easy for an academic at a round table to claim that we live in a post-ideological universe, but the moment he visits the lavatory after the heated discussion, he is again knee-deep in ideology.” -Slavoj Žižek


I wish there were more modern thinkers like Zizek.


Is it supposed to float? I don’t think I’ve ever had a poo that floated.


You have your guts to thank for that.

Where's dang and his helpful links to recent relevant discussions when you need him? I'm happy to drop this in:

Why some feces float and others sink (phys.org)

https://news.ycombinator.com/item?id=33691619

https://phys.org/news/2022-11-feces.html

There needs to be another "fart content" dimension to the Bristol Stool Scale.

https://en.wikipedia.org/wiki/Bristol_stool_scale


In the old school German (and dutch) toilets, the shit lands on basically a shelf, for inspection.

You then flush it and it fucks off into the abyss.

The reason for the "poop inspection shelf" apparently was so you could take a quick look at your turd and see if it displayed signs of illness. Like say, blood.


Zizek is fashionable nonsense and is a charlatan and hack at the same level as Jacques Lacan (who he also cites a lot)

Better to avoid their kind of drivel.


Oh, the poop shelf, so you can examine your stool before you send it into the abyss.

They are also occurring in the Netherlands.


I seriously have no clue whether you guys are being sarcastic, do you actually not close the lid before flushing? Also, public toilets with lids is the majority of cases in Sweden. And peeing on a metal sheet also releases particles, so who cares about the urinal.


The US has some crazy toilet regulations and customs.

No lids. In many places the law requires weird U-shaped open seats. Paid toilets are verboten in most places, too. And the cubicles of public toilets typically don't got all the way to the floor nor ceiling and even have vertical slits to peek.


Apparently, the reason the doors don't go all the way to the floor is to meet stipulations in the Americans with Disabilities Act which are to allow wheelchair users to turn[1].

[1] https://travel.stackexchange.com/a/62354/19042


Yesterday I was in a Boston, MA bathroom where the stall doors were floor to ceiling. Even the wheelchair accessible stall had a floor-to-ceiling door.

I've always understood the difference to be cultural and economics driven: US stall partitions are cheaper than walls and floor-to-ceiling doors; so the (cough) pooping closets really are only in upscale bathrooms.

(BTW, in the 1990s a Boston-area radio station used to broadcast bits where they would sit in a stall and strike up a conversation with whoever sat next to them.)


Also apparently, the toe clearance (the gap) isn't a requirement if the stalls are wide enough. Maybe that's why?

> (BTW, in the 1990s a Boston-area radio station used to broadcast bits where they would sit in a stall and strike up a conversation with whoever sat next to them.)

I'm British and I think we have just found the most important, deepest cultural difference between the UK and the US there is!


As a Brit, you should tell them about your carpeted (private) bathrooms.


When I was a kid, we had a carpeted bathroom toilet area.

What lunacy. Mold grows easily (carpet was always damp in high humidity summers, due to condensation, near the toilet), and worse, one bad flush and your carpet is now literally encrusted with human shit.

How do you feel comfortable keeping it clean?!


West europe uses a separate disabled toilets, typically much larger, have plenty of places to hold and grip, larger toilet seat, a "help me" cord to pull, friendlier taps, etc.

An example: https://4.bp.blogspot.com/-VQ-IG8pFfcs/WQYWuWexVmI/AAAAAAAAd...

No, too much work? Instead just infringe on the privacy of everyone else.

Honestly...


I understand we all have different cultural norms, but I have never felt that my privacy was infringed on by the potential that a stranger may see my shoes while taking a crap.

But then again, I went to plenty of bars in college with trough urinals, so maybe I have a different point of comparison.


That's what's really weird in the states - there's a partition between urinals, but turn around and there's half-inch gaps between the door and rest of the cubicle!


There's not always partitions, i.e. the troughs I referenced.

The clearances around the stall doors have never occurred to me as an issue. Nobody stands outside of a stall door with their face stuck in the door crack.


That pattern preceded the ADA, as far back as I can remember. Wouldn't surprise me if this law locked it in after it became standard, though.


Probably started in saloons so that the local sheriff could walk through and check for any fugitives by looking at their cowboy boots.


Low rep poster, no citations. I'm going to call [citation needed] on that. The door is often perpendicular to the toilet so the explanation doesn't even really make sense…


I thought it was bunk as well, but there is a comment actually quoting an ADA building guide directly that confirms it:

https://up.codes/viewer/ada/chapter/6/plumbing-elements-and-...


"Toe clearance at the front partition is not required in a compartment greater than 62 inches (1575 mm) deep"


No, I don't, and I don't think I've suffered any negative consequences. But I've also never lived in a place that had the toilet placed in the bathroom. I guess if I were flushing the toilet next to my sink and my toothbrush, I might think differently about it.


> I've also never lived in a place that had the toilet placed in the bathroom.

Where is your toilet?


Can't speak for OP particularly, but many newer houses in the US have the toilet in its own small room separate from the rest of the bathroom where the sinks, shower, and soaker tub are.

Though in my household I can say the door to the small room rarely gets closed and I can't convince anyone else to put the damn lid down. Until slurp-slurp-slurp the dog starts drinking it, in which case there's a "stop drinking from the bowl!" followed by closing the lid. I'm not bitter. I try to choose my battles, and "turn the fan on when you poop" is a hill more worthy of dying on. Still haven't really succeeded with the kids yet.


> Can't speak for OP particularly, but many newer houses in the US have the toilet in its own small room separate from the rest of the bathroom where the sinks, shower, and soaker tub are.

I hate this type of setup, because it means I have to walk to another room before I can properly wash. Then again, I believe many people only use toilet paper in the US, so they are probably used to it..


> turn the fan on when you poop

Windows also work well.


A window might blow air out, but it also might blow air in. This would result in drawing your bathroom air deeper into the house instead of exiting it. A proper vent fan will undoubtedly move the air outside.


> A proper vent fan

I don't think I have ever, in my life, been in a bathroom with a "proper" vent fan. AFAICT by observation, regulations must require a fan that makes seems to only make "chugchugchug" noises while seemingly doing nothing to the air.


Lots of vent fans in houses tend to not actually vent anywhere, or they're covered up with insulation. I know I had to dig my vent fans out when I moved into my house. Uncovering them led them to be much quieter and actually exhaust from the bathroom.

Good bathroom ventilation is important. Controlling humidity is a big thing, but also properly ventilating things like acetone or hairspray or other things along with bad odors is important.


> Lots of vent fans in houses tend to not actually vent anywhere, or they're covered up with insulation.

I do a lot of house repairs. I don't think I've ever seen a bathroom fan that goes outside except in mobile homes. They just vent into the attic. Same with many kitchen fans. They should all go to the outside otherwise they could cause moisture issues in the future.


In the water closet, of course.


Public/industrial/commercial toilets in the US generally do not have lids, only seats.

They also seem to flush a lot more violently than residential toilets, relevant to the issue raised by TFA.

It is strange to me that there are two parallel systems. I imagine the commercial ones require less maintenance but are more expensive?


> It is strange to me that there are two parallel systems. I imagine the commercial ones require less maintenance but are more expensive?

There's a lot more laws and regulations for the 'commercial' toilets. Eg the U-shaped open seat is mandatory for public toilets in many places in the US. It's not a choice they make for commercial considerations.

Btw, 'commercial' toilet is a bit of a misnomer: it's against the law to run a toilet business in most of the US. (Specifically paid toilets are outlawed.)


It's fascinating to me how often things get codified into law or standards[1], but the reasoning behind it becomes legend.

Apparently the u-shape is intended to allow women to wipe without touching the seat, and maybe also reduce male contact with the front. But you have to take a bunch of people's word (which I suspect to be guesses) for that.

[1] and I've been on standards committees where people are trying to imagine what the previous generation were trying to say, since standards usually only tell you what, and are short on the why.


Where is the "commercial toilets must have U-shaped seats" law found?

Most "commercial toilets" are designed to be easy to clean and run off of "mains" pressure - commercial buildings have enough flow that they can flush directly without storing a buffer in a tank. And many commercial businesses have normal "home" toilets, at least around here.


A tiny bit of Googling gives https://www.rd.com/article/public-toilet-seat-u-shape/ gives:

> This is an open-front toilet seat, and thanks to the American Standard National Plumbing Code, it’s the go-to for most public restrooms. This code was created in 1955 and further cemented by the Uniform Plumbing Code in 1973 by the International Association of Plumbing and Mechanical Officials (IAPMO).

You can follow the links in the article I linked, or do a bit more Googling.

It's not a single uniform law, but a code that then got (and gets) adopted by lots of localities using different legal mechanisms. See https://en.wikipedia.org/wiki/Uniform_Plumbing_Code


A lid is not a panacea. The force behind a toilet flush, especially a commercial one, just blows the particles out the sides under the seat and lid.

You pee on a metal sheet? Fascinating. Does nobody wear shorts in Sweden? ;-)


>You pee on a metal sheet? Fascinating. Does nobody wear shorts in Sweden? ;-)

Average bar urinal: https://www.sweppomn.se/wp-content/uploads/2020/02/14800038_...

Also yes, we do wear shorts, that's how no one sees that we've peed on our own legs :-).


Complete with art! Looks almost exactly like a bar I go to here (in Oregon), all the way down to the blue walls and graffiti. But most of our establishments have regular toilets, by far. Another local bar has a pretty spacious bathroom, the requisite graffiti and such, but a lone lidless toilet. Concrete floor and a drain, too, which is good because it seems that drunk people like to use the open toilet as a challenge, to see if they can hit it from afar. They often miss.


About your later point: Isn´t pee supposed to be a mostly sterile liquid?


Its not sterile at all. Why do you think they test it for bacterial cultures when you've got an infection?


it's not likely to be harmful but that it is sterile is a falsehood probably popularized by Fight Club


No, this belief goes way back, like pre-WW2.

My father would tell a story explaining why one foot was scarred and ticklish that involved the neighborhood kids pissing on his bleeding foot after stepping on a broken bottle while playing soccer barefoot in the plaza back home in Italy. All the kids knew to piss on the wound to sterilize it. He was born in '42.


> popularized by Fight Club

And Lawrence of Arabia in the Seven Pillars of Wisdom. In which the young men piss on wounds.

"The other wounded men were seen to at the same time. Mifleh brought up the youngest lads of the party, and had them spray the wounds with their piss, as a rude antiseptic."

Last paragraph of chapter 78: https://www.globalgreyebooks.com/seven-pillars-of-wisdom-ebo...


I hate it, but loads of people don't close the lid at all, it's just some sort of decoration to them, I don't know.

You can often tell these people without ever sharing a lavatory with them - they'll joke about the woman/women in their life training them to 'put the seat down' (or similar from the female perspective) - as if that's all there is to put down, and consequently the women using it have nothing to close.

(It sounds like a weirdly niche thing to joke about, but for some reason it seems to be popular. I suppose such people think it's very relatable, not realising how exposing or even class-determining it is.)


Ultimately the hygiene benefits of closing the lid when flushing are negligible in most situations. These studies always show evocative images of aerosol spreading from toilets when flushing, which understandably elicits a disgust response in certain individuals, but they fail to show that e.g. homes where the lid always stays up have higher rates of disease, or that the pathogen exposure from flushing has any real impact on health.

Also given that the majority of people flush without closing the lid (I suspected this but just confirmed with a quick search) it's a bit weird referring to them as "these people" whose type you can tell. I don't think this habit is constrained to those who publicly joke about it.


> Ultimately the hygiene benefits of closing the lid when flushing are negligible in most situations.

I wasn't commenting on any supposed benefits for flushing, purely aesthetics and manners.

> [studies fail to show they] have higher rates of disease, or that the pathogen exposure

Nor did I claim anything of the sort.

> it's a bit weird referring to them as "these people"

Are they not people? They are certainly not all people. What would you have me say?

> I don't think this habit is constrained to those who publicly joke about it.

Nor do I, I said you can 'often' tell. The public joking happens often (enough for it to come to mind, evidently) and you can tell that about those people. I made no claim about the others - though if they're laughing at the joke that's probably a good indicator too.


Playing devil’s advocate in this important topic… There are arguments to have the lid down or up, and I get that you find it vulgar, but exposing your class?


Yes, that goes hand in hand with finding it ill-mannered or vulgar, doesn't it? To be fair, in turn caring at all I suppose 'exposes' me as someone who shares lavatories, and without a chap to give them a once over before (and perhaps after) hand.


This is big reason why I prefer work form home - I get to comfortably shit in my own toilet. That is a luxury that cannot be underestimated.


Home is where the bidet is installed


And I don't have to share a bathroom or office or work space with something like 30% of people who just refuse to wash their hands after using the bathroom.

What is wrong with all of you?


It's a productivity booster too. I can discreetly go about my business during meetings, off camera of course, without skipping a beat. And no one is the wiser. What a time to be alive!


I remember hearing about this for the first time not too long after Covid started, there must be another study that is 1-2 years old.

Edit:

* Here is one from December 2021: https://www.public-health.uiowa.edu/news-items/study-on-toil...

* Here is another one from May 2020: https://aip.scitation.org/doi/10.1063/5.0013318 ("...It is clear from daily experience that flushing a toilet generates strong turbulence within the bowl. Will this flushing-induced turbulent flow expel aerosol particles containing viruses out of the bowl? This paper adopts computational fluid dynamics to explore and visualize the characteristics of fluid flow during toilet flushing and the influence of flushing on the spread of virus aerosol particles....")


This reminds me of Al Bundy and his love for the Ferguson, the king of the toilets.

https://marriedwithchildren.fandom.com/wiki/Ferguson_Toilet



IIRC right at the beginning of COVID there was speculation it could be spread by air discharge from sewer stack vent pipes; that later turned out to be very likely but no one wanted to talk about "airborne" at that time.

"We" as beings are at least as much the micro biome that inhabits and surrounds us as we are ourselves. Sharing those pools of semi-independent life with each other; letting them taste the world we live in and adapt to the locale we're in today, is probably more important than we want to recognize. Closing the lid when you flush may well be a fundamentally uncivil act.


Scientists have found it only now, but I have always thought about it. :D ... I have always wondered why no one has invented a toilet with an auto-closeable, auto-cleanable "inner lid" (sitting collapsed just below the seat) that closes only while you're flushing so that all that flush water tsunami doesn't come out on my floor and everywhere else.

If a potential founder and creator is interested, I have a design in mind for the same. :)


When I was a kid (almost 40 years ago) the family we went camping with had this setup. A toilet that that put over a long drop, and when you sat on the seat the the pressure would open the inner seat, effectively splitting it in two and pulling it away to open the hole below.

I’d assumed it was some standard pro camping kit. By no amount of searching just now has been able to turn up a device like I’m trying to describe!


My Airhead composting toilet has an inner door that's opened by a small handle once you are ready to make your deposit.


Wow. That should have become a household design by now.


Scientists have know that particles come up for a long time. This study visualized them. Here's an excerpt from this article:

> Researchers have known for over 60 years that when a toilet is flushed, solids and liquids go down as designed, but tiny, invisible particles are also released into the air.

Do we need to come up with something new? What if we start closing the lid that is already there before flushing?


Yes, I was mostly kidding that Scientists found out only now. But we definitely need a new design. Closing the lid is ugly (someone who has always thought about invisible splashes falling up on the floor and toilet seat wouldn't think about that?). When you close the lid and flush, all those tiny little particles are sticking on the lid instead now. And when you open that again and sit, unintentionally some part of our backs (/clothes) do touch that - not helping much. Also ideally it doesn't save the toilet seat as well since even when closed the lid is still above the seat. That's why an auto-closeable inner lid that seats beneath the toilet seat is a solution (or like someone else suggested, it always remains closed but opens up only by the pressure of someone sitting on it).


It would be nice if the solution to this did not require any effort.

Part of the problem with any automatic thing is that it is more prone to failure. Toilets are so ubiquitous that if something like this were to have an impact, it would need to be close-to-unbreakable.

No this thread got me sitting here thinking about toilets and trying to come up with a design that solves this, and an outhouse comes to mind. <grin>


This experiment was done on a public-style (commercial) toilet. They do not have lids.


Any idea what proportion of public toilets in the US do not have lids?


100%?

At least, I’ve never seen a public toilet with a lid.


I'm definitely not a plumber but I know toilets with a rather slow flush which probably wouldn't throw much plume - although that might be a different design than the US ones and require wider drain pipes.


There are designs where the flush button is on the front of the cistern, so in order to flush, you have to close the lid.


For urinating, Larry David beat you to it with his innovative 'Pee Cube' design.


So on top of having to raise the seat to pee, we now have to lower the lid to flush?!


Or stop worrying about it unless you are shedding pathogens, in which case I suspect it's not really enough to achieve the objective of stopping cross contamination.


> raise the seat to pee

You don't need to do this. Just sit, it's cleaner and healthier :-)


Sitting is the worst. It's impossible to pee completely. Even when defecating I need to stand up and pee afterwards. Also not sure why touching the toilet seat with my legs would be "cleaner".


Do you have any evidence of this? I've sat to pee my entire life and have never run into this and indeed experience the opposite, where no matter how much you shake it and try and force everything out, when you put your dick back in your pants it always finds more pee to drip down your shorts.


It's my direct personal experience. What kind of evidence do you expect, a video?


Only if I start writing managed code


Ah, the decline of western civilization continues.


What do you think the lid is there for?


It's to assist you when you need to replace the ceiling light bulb, no?


Or to change a clock? But you might slip off, hit your head, and invent time travel.


To keep the dog & cat from drinking out of it. Very unpopular with the quadrupeds & half of the bipeds.

The growth that occurs on the underside of the lid makes for a good reminder that cleaning the toilet is (over-)due.


Also to keep the toddler from playing in it.


I mainly use it as a footstool when I cut my toenails.


To sit down whilst the kids are in the bath.


to escape life and watch tiktok for 2 hrs.


Many public toilets where I live have no lids.


Or use a urinal (should be available in most public toilets). They have no lid, but often an automatic flushing mechanism, so if you run away fast enough you have a chance to avoid the plume...


There are also urinals with lids, but i have not seen them on public toilets.


And raise the lid to pee, preferably.


Yes.


Sounds like something could be learned here from space toilets, which rely on suction (not gravity). Check out NASA's $23 million new design:

https://www.smithsonianmag.com/science-nature/nasa-just-sent...

> "The new toilet is a compact cylinder standing about 28 inches tall and features the same type of fan system, as well as a funnel attached to a hose, as previous iterations. It also has a removable waste compactor for the astronauts to deposit their droppings in. Each time an astronaut poops, their business is sucked into a baggie. Once finished, the astronaut will seal the baggie up, and push the packaged poop down into the canister. They then install a new baggie and the process repeats until the canister is full. As the canister fills up, the bathroom stall may not always smell so fresh. The collection bin holds roughly 30 deposits. Once the bin is full, the poop is then discarded with the rest of the trash into outer space."

The idea of bags of human poop (including trillions of microbiome bacteria) floating forever in deep space orbits is rather odd. This seems like an orbital debris hazard?


Space stations aren't deep space it's like 200 miles away from where I'm sitting. Geostationary is something like 100 times that and even out there orbital decay is on the scale of like, a human lifetime or two.

This general concept is definitely something for us to consider but this isn't a specific case we need to worry about, I think.


Geostationary orbits are well beyond measurable atmospheric drag; the expected lifetime is on the order of millions of years. Geostationary satellites do have a limited oeprational lifespan, but it's not because of orbital decay, it's because they need propellant for stationkeeping to adjust for irregularities in the orbit, and that propellant is finite and eventually runs out.


Orbital decay is indeed quite fast at space station levels, but geostationary decay takes roughly forever. (There are geosynchronous orbits that decay quickly, but only at certain inclinations.)


They don't float forever - any object orbiting at the altitude of the ISS will decay from atmospheric drag, generally on time scales of a few months to years.

Human spaceflights at altitudes beyond significant atmospheric drag would need another solution, but we haven't done any of those since 1972.


> Thanks to new CU Boulder research, scientists see the impact of flushing the toilet in a whole new light—and now, the world can as well.

Great pun if intended


To what extent do we know that low-level exposure to degraded / intact pathogens is immunoprotective?



News flash: the world is dirty. Maybe they should take their magical green laser outside and play, like we ask our children to do. I bet there's lots of horrible things coming up from walking through the underbrush behind my house.


If you're interested in how to engineer a state of the art, self-cleaning toilet, San Francisco famously spent $1,700,000 on a single public toilet installation.

Here's a video on one of SF's new self-cleaning toilet pods: https://www.youtube.com/watch?v=nmFve_DI5mI

[Edit] The toilet in the video is not the $1.7M one, but it's a similar design AFAIK. The video is interesting for the engineering of the toilet pod. The $1.7M comment references a larger story about the politics involved in engineering and installing public toilets in the US.


Your comment might be interpreted incorrectly. According to the video, the silver toilet in the video is not the one that cost $1.7m; the video says it was provided by JCDecaux in exchange for some advertising rights.


Thanks valleyer. I edited the comment for clarity. The engineering involved is interesting. The politics and cost are just noise, but worth referencing because it became a clickbait story at the national level. It illustrates the complications for balancing good engineering with public perception and competing interests in the US.


Also:

“It all started with an enquiry from a nurse,” Dr Karl Kruszelnicki told listeners to his science phone-in show on the Triple J radio station in Brisbane. “She wanted to know whether she was contaminating the operating theatre she worked in by quietly farting in the sterile environment during operations, and I realised that I didn't know. But I was determined to find out.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1121900/


The paper's methods section is nice to read. They convert a line laser to a sheet (illuminating a plane).

I was disappointed they didn't use a poop surrogate (https://www.mentalfloss.com/article/56003/recipe-fake-poop)

Office toilets are pretty bad- they really do churn up a lot more than a home toilet.

A few times I've had to reach over the toilet for a flush and felt a mist which roughly correlates to what you see in the videos.


Published paper: Commercial toilets emit energetic and rapidly spreading aerosol plumes https://www.nature.com/articles/s41598-022-24686-5

Related: Lifting the lid on toilet plume aerosol: A literature review with suggestions for future research https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692156/


I remember Dave Barry bringing this up the mid 90s. "So we see that a toilet is really nothing more than -- to use scientific parlance -- a Yuck Bomb."

I've kept my toothbrush in my bedroom ever since.

ref: https://www.baltimoresun.com/news/bs-xpm-1995-04-30-19951201...


Aren't most of those water bubbles from the fresh water that is coming in?

Last time I checked these high powered toilets first suck things down, then fill it up with water.

The scary plume seems like a recurring pattern of scientists using scaremongering to validate the rationale for doing science.

I recall a similar photo of a scary plume of supposedly infectious COVID particles trailing a runner outside ... all that turned out to be nonsense.


> Last time I checked these high powered toilets first suck things down, then fill it up with water.

No toilet except those found in airplanes can actually suck things down without first having water come in from the top. The sucking action is created by water entering the bowl and coming over the top of the trap, and the water exiting down the drain then creates a vacuum that sucks the remaining water down.

High-pressure toilets simply create more pressure at the top, they don't do any suction first.


I could have sworn this meta level concept was discussed ages ago in one of those Klutz press science tween science books they’d sell at places like Natural Wonders in the 2000s.

(It’s still cool research just jogged my memory- iirc they had Mark Hamill telling you the benefits of closing the lid on the toilet before flushing.)


Add a bidet to this equation and it will blow your mind. Best not to dive too deep into this.


At least you don't need UV light to see the spray!

https://www.youtube.com/watch?v=Iu2psmj1whE


We collectively have been operating loos this way, or similar, for decades. I wonder, is it causing health issues of significance? And, should a 'cleaner' way of flushing be adopted, will we collectively be ill less?


For public toilets, will mask help in avoiding this hazard?


I think a little exposure to aerosolized particles is nothing bad. Hygiene is important but I also think building resistance is important.


We've known this for ages, and it's useless without quantifying the risk of getting sick from it.


This is addressed in the article...

> Researchers have known for over 60 years that when a toilet is flushed, solids and liquids go down as designed, but tiny, invisible particles are also released into the air. Previous studies have used scientific instruments to detect the presence of these airborne particles above flushed toilets and shown that larger ones can land on surrounding surfaces, but until now, no one understood what these plumes looked like or how the particles got there.


Most science is extremely iterative or investigative, not ground breaking.


At home, I do this thing where I push the flush lever right as doody is coming out. When I time it right, it sort of goes down exactly at the bottom of the whirlpool, no smell. I figure if I keep under the rim and everything else clean, it hopefully makes for no offensive ejecta. I can't be the only one who cares about this.


That's not a problem if you have Turkish or Russian toilets...


Someone watched Mythbusters...


Why not close the lid first?


Most public toilets in the US do not have a lid.


I harbored a thought that this was the prime spreader of COVID back when shutdowns were working. Shared bathrooms.

Is also why I hypothesized that home spread was lower. Since many homes have naturally segregated bathrooms for kids over the parents.

Pretty sure this didn't pan out, mind.


Why the heck did you think the prime spreader of covid was through pee or feces instead of, you know, people coughing around each other like nearly every other respiratory infection?


Ha! What happens when I post quickly from the phone. I didn't mean this to be that I thought it was the prime spreader. I thought it was a vector that could explain office and some community spread in ways that other events weren't the same.

Edit: I should say, as I realize it isn't obvious on reread. I posted this as an amusing confession. Not because I think it is a thing.


So a curtesy flush on these toilets seems quite disgusting now.


And don’t get me started about urinal troughs…


That’s gross




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