The idea is that if an infected person poops into a toilet, toilet plume (remember Cecil’s column about it?) from the flush causes virus-carrying aerosols to be propelled a few feet in the air, where they can linger until the next person uses that stall. And that person might inhale the aerosols.
It appears that the risk of transmission by this means is unclear, but probably relatively low.
But the proposed solution - closing the lid before flushing - seems out of place. That may work at home, but you’re breathing the exhaled air of your family members or housemates all the time anyway. And public toilets rarely have lids. So if one’s worried about this means of transmission, really the only remedy is just not using public toilets while out and about, unless you’re absolutely desperate.
Closing the lid before flushing is more sanitary. When you flush, you put out an aerosol containing whatever you just put into the toilet, and for hygiene reasons you don’t want to spread this (even if you can’t see or smell what’s coming out). This isn’t really a coronavirus issue.
I recall a study about farting spreading the coronavirus. True, if you’re not wearing underwear or anything else on your lower body. I think in most countries, walking with the lower body completely exposed in public is pretty rare. (I imagine nudists will have to modify their clothing routines for health reasons during the pandemic, since underpants are probably even more protective than masks. I am not suggesting using underwear masks though.)
Dave Barry did a column a hundred years or so ago about toilet plumage. His main suggestion was to MOVE YOUR TOOTHBRUSH. In most bathrooms, the tooth brush storage is practically on top of the toilet.
He said closing the toilet lid before flushing has the appearance of stopping the plume. However, the aerosolized effluvia remain suspended in the air over the toilet bowl surface, and as soon as you pick up the lid to do your business, you are greeted with a faceful of aerosolized you-know-what.
I have enough to worry about already. I choose not to dwell on toilet plumes.
~VOW
Cecil suggested that “toilet aerosol is probably the more accurate term.”
As I understand it, a standard American toilet flush is triggered by adding a small amount of water to the bowl, which is sufficient to start the siphon to suck* the water out of the bowl, which empties then refills.
In Aus, a standard toilet flush starts by adding a lot of water to an almost empty bowl, and the rushing water carries the contents out. Which could be why Australian research showed that closing the toilet lid just pressurized the contents, causing a high-pressure plume to squirt out around the lid.
It’s of course gross, but living in the same household is going to expose you to those germs anyway. And while guests occasionally poop in my toilet, it is pretty rare. And if they are in my house, I’m inhaling their germs anyway.
It’s old news that toilet plumes can spread germs. But is there any particular reason to suspect that they specifically spread coronavirus germs? I wouldn’t expect a high load of a respiratory virus in fecal matter. Or, as I suspect, is this just someone seizing on a piece of old news and trying to re-sensationalize it by saying “And COVID!”?
Covid-19 isn’t exclusively a respiratory virus. It is known to infect the lining of the gut, which is why it can cause diarrhoea. Not everyone with a Covid-19 gets such an infection, which is probably why the study noted that not everyone has a high faecal load of virus.
I suppose even scientists could be trying to sensationalize something by publishing a research paper such as the one that prompted the WaPo story I linked to.
Looks like there is some potential for human-safe UV that could be installed in bathrooms and left on continuously. It would mitigate lingering aerosols like this.
Still early in safety studies (so far, only on rats), but results are encouraging.