"How long diseases like measles and the flu linger in the air — after an infected person has left the room"
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@Lkdc so I suggest figure 6 from https://www.nature.com/articles/s41467-024-47777-5
Yes, waiting a short time would reduce airborne load.
It would also help to open a window - both for ACH and because lower CO2 speeds viable virus degradation.
The long tail hard to avoid. If the bathroom is ventilated to 3 ACH it's not "the air is completely gone 3x an hour" but "thrice the volume of air in the room is exchanged per hour" and so forth.
If it's a scenario you face, you could consider augmenting whatever ventilation the common bathroom has with UV disinfection, since it's likely much easier to plug in an emitter than to upgrade ventilation.
I believe there's a correlation between inoculum dose and negative outcomes.
So yes I would understand waiting until the first two phases are expected to pass if possible (their durations can be estimated from that paper and checking humidity (RH) and CO2), and then ACH or UV sterilization to bring down the long tail until it's within your risk budget.
@datum @Lkdc Yes, as much fresh airflow and time as you can give it is good. It will pretty much always help to wait as long as you're able.
Also, if you can arrange a setup to wash just your face in a lower risk environment, like outdoors with a bowl of water or something, then you can shower with a respirator on. It's not anyone's first choice, but for the couple weeks while the other person is sick, it can be a reasonable precaution. Here's some testing with 3M Auras:
https://xcancel.com/AdvancedTweaker/status/1815930182064300274 -
@datum @Lkdc Yes, as much fresh airflow and time as you can give it is good. It will pretty much always help to wait as long as you're able.
Also, if you can arrange a setup to wash just your face in a lower risk environment, like outdoors with a bowl of water or something, then you can shower with a respirator on. It's not anyone's first choice, but for the couple weeks while the other person is sick, it can be a reasonable precaution. Here's some testing with 3M Auras:
https://xcancel.com/AdvancedTweaker/status/1815930182064300274@datum @Lkdc Conveniently, the fluid-resistant 3M Aura 1870+
is available by the ~440ct case for only $50:
https://amazon.com/dp/B0937JGMY7So, you can go with a combination of giving the bathroom time to air out plus wearing a respirator to reduce the risk even further.
(Not all respirators are likely to hold up quite as well as the 3M Auras did, so you shouldn't assume that this testing applies perfectly to all other models. However, many quality models should still function ok when damp.)
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@jmcrookston @datum I'm trying to understand what all this means, in practical terms, for covid-cautious people who live with people who take no covid precautions. A common concern is removing one's respirator to take a shower in a bathroom that has recently been used by someone who might be infected with SARS-CoV-2. I've been under the impression that there's value in waiting even a short time (15-60 minutes), as the risk will go down, albeit not to zero. Is that incorrect?
@Lkdc @jmcrookston @datum Also, the probably blazingly obvious, ensure everyone knows to lower the toilet lid when flushing. You'd THINK, but I once found out someone I knew was *raising* it to flush because they regarded it as some kind of chair back, and by lowering it while flushing, it got icky… so you never know.
Having lived mostly in apartments without bathroom windows, after some minutes of any combination of window and/or exhaust fan ventilation, I'd also consider running a CR box in there for a few minutes ahead of showers. Agitating the air seems like a reasonable way of helping eliminate the total amount of unfiltered air, e.g. spilling out of upward-cupped light fixtures when the temperature rises.
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"How long diseases like measles and the flu linger in the air — after an infected person has left the room"
RSV: up to 45 mins
Influenza: at least 1 hour
Rhinovirus: 1-2 hours
Measles: up to 2 hours
Norovirus: up to 2 hours
COVID-19: up to 3 hours
Chickenpox: several hours
Mumps: several hours
Tuberculosis (TB): 6-12 hoursSource: https://archive.md/dKnQP
@DenisCOVIDinfoguy yay! the air's bugged and the water's got plastics in it! we're off to a great start in our next evolutionary step
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@DenisCOVIDinfoguy instead of just accepting these numbers, get air purifiers for spaces you control, and push the owners of space you don't control to do it too
@draNgNon @DenisCOVIDinfoguy
Safe indoor air requires:
Dilution (bring in outside air)
Filtration
Circulation
Exhaust.UV, ozone, etc cleaning of air is dangerous. (Unless you are a hospital with competent HVAC people).
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"How long diseases like measles and the flu linger in the air — after an infected person has left the room"
RSV: up to 45 mins
Influenza: at least 1 hour
Rhinovirus: 1-2 hours
Measles: up to 2 hours
Norovirus: up to 2 hours
COVID-19: up to 3 hours
Chickenpox: several hours
Mumps: several hours
Tuberculosis (TB): 6-12 hoursSource: https://archive.md/dKnQP
The hard-headed insistence of public health officials (PHO) on emphasizing COVID transmission via fomites vs aerosols caused, in IMO, immense harm. Even a year or more into the pandemic, PHO were delivering confused and incorrect advise about masking, etc. It's not my field, but to this layperson, it appears as if modern medicine remains very confused and ill/un/mis-informed regarding aerosol disease transmission. Unclear what accounts for this.
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"How long diseases like measles and the flu linger in the air — after an infected person has left the room"
RSV: up to 45 mins
Influenza: at least 1 hour
Rhinovirus: 1-2 hours
Measles: up to 2 hours
Norovirus: up to 2 hours
COVID-19: up to 3 hours
Chickenpox: several hours
Mumps: several hours
Tuberculosis (TB): 6-12 hoursSource: https://archive.md/dKnQP
@DenisCOVIDinfoguy We are wet bags of germs, swimming together in a sea of air.
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@Lkdc @jmcrookston @datum Also, the probably blazingly obvious, ensure everyone knows to lower the toilet lid when flushing. You'd THINK, but I once found out someone I knew was *raising* it to flush because they regarded it as some kind of chair back, and by lowering it while flushing, it got icky… so you never know.
Having lived mostly in apartments without bathroom windows, after some minutes of any combination of window and/or exhaust fan ventilation, I'd also consider running a CR box in there for a few minutes ahead of showers. Agitating the air seems like a reasonable way of helping eliminate the total amount of unfiltered air, e.g. spilling out of upward-cupped light fixtures when the temperature rises.
@cwicseolfor @Lkdc 100% yes to CR boxes. I started suggesting one in the first place then pulled back to ACH since any mechanism works, and I didn't want to tangent down "if the air is steamed will MERV filters get soggy enough to maybe go mouldy with time".
I had never even considered
spilling out of upward-cupped light fixtures when the temperature rises.
so thank you for the reminder that in any actual instance, air is a fluid filling a space and that it must be mentally modeled as such.
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@datum @Lkdc Conveniently, the fluid-resistant 3M Aura 1870+
is available by the ~440ct case for only $50:
https://amazon.com/dp/B0937JGMY7So, you can go with a combination of giving the bathroom time to air out plus wearing a respirator to reduce the risk even further.
(Not all respirators are likely to hold up quite as well as the 3M Auras did, so you shouldn't assume that this testing applies perfectly to all other models. However, many quality models should still function ok when damp.)
@Texan_Reverend thank you for the reference to a fluid-resistant mask, and also WOW those are inexpensive!!! Nice!!!
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@datum I would like to hear some information about how contagious this virus is outdoors playing sports with people.
I've had to give up five years of pickelball becasue of this virus.
@Scienceisnotopinions I would mask to play, if I were you.
Outdoors the plumes don't have a ceiling to hit, cool at, and rain down from, BUT as @NilaJones and others know all too well, one can smell a smoker from many metres away downwind, which means one can inhale their exhalation, and you won't be able to stay upwind of every other player all game.
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@datum yes if ventilation I meant. Which can be slow or fast of course. If nothing then yes it's agglutination (I understand the particles tend toward certain sizes) and deposition on walls and ceiling and floor. Like cigarette smoke. Should hang out for a long while.
If people want to know how long they can just burn some toast on a pan. Then they can tell us how long that smoke hangs out
If they really want to be bright, they could run their air purifier and see how quickly it clears the air
If people want to know how long they can just burn some toast on a pan. Then they can tell us how long that smoke hangs out
Oooh this would be a great science experiment for kids to run too, in the same vein as the UV handwashing experiment. A visceral, visible or smellable result is way more impactful to kids than abstract words and pictures. Great idea!
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@datum @Lkdc Yes, as much fresh airflow and time as you can give it is good. It will pretty much always help to wait as long as you're able.
Also, if you can arrange a setup to wash just your face in a lower risk environment, like outdoors with a bowl of water or something, then you can shower with a respirator on. It's not anyone's first choice, but for the couple weeks while the other person is sick, it can be a reasonable precaution. Here's some testing with 3M Auras:
https://xcancel.com/AdvancedTweaker/status/1815930182064300274@Texan_Reverend @Lkdc an hour of swimming - 6 hours of wear - no noticeable drop in effectiveness!
Thanks for forwarding that person's testing!!
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If people want to know how long they can just burn some toast on a pan. Then they can tell us how long that smoke hangs out
Oooh this would be a great science experiment for kids to run too, in the same vein as the UV handwashing experiment. A visceral, visible or smellable result is way more impactful to kids than abstract words and pictures. Great idea!
Yeah, the origin of this thought was that once I burned something on a pan. This is exactly what I did. I opened windows and the haze didn't go anywhere. So eventually I turned on my big air purifier and the haze was gone in 2 to 3 minutes on maximum. It really shows you that the particles aren't going anywhere even if you have windows open. You have to actually have airflow. There's often not a lot of air flow through a window. I even had fans blowing out and not much got exhausted.
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@Texan_Reverend thank you for the reference to a fluid-resistant mask, and also WOW those are inexpensive!!! Nice!!!
@datum And if you're interested in having other fluid-resistant options available, it's a feature noted on all the relevant models in the Sourcing section of the Masking Reference Doc here:
https://texanalysis.comFor instance, lots of folks really like the comfort and low breathing resistance of the 3M VFlex 9205
along with the fact that they cost less than a dollar a piece.
The 3M VFlex 1804 version adds fluid-resistance to that list of good qualities. -
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