Seems no-one in the UK is talking about the need to HUMIDIFY air

[Kokeshi123]

There is already a lot of evidence that this virus is being spread largely through the air, and that clean air matters a lot more than clean hands and surfaces (Yes, do wash your hands as well. Don't expect it to really dent the numbers of cases or deaths).

It seems like the UK has in the last couple of months cottoned on to the importance of ventilating rooms as much as possible. However, it appears that there is very little talk about the benefits of humidifying rooms as well.

www3.nhk.or.jp/news/html/20201013/k10012661241000.html?utm_int=news_contents_news-main_003

This is just a sample, but the study here in Japan found that the spread of the virus is increased around three-fold in dry air versus humidified air. This is actually no surprise, because variations on this theme have long been noted in the scientific literature. For other seasonal viruses (influenza, colds etc.) as well as many other viral infections like measles, viral spread is greatly reduced when the air is humidified.

Is humidity the key to staying healthy?
www.boston25news.com/news/is-humidity-the-key-to-staying-healthy-/1012463681/

This Inexpensive Action Lowers Hospital Infections And Protects Against Flu Season (this article discusses the mechanism by which humidity reduces the spread of viral particles)
www.forbes.com/sites/leahbinder/2019/10/17/harvard-researcher-says-this-inexpensive-action-will-lower-hospital-infection-rates-and-protect-us-for-the-flu-season/#3b398a4a1824

While all those factors had modest influence, one factor stood out above them all, and it shocked the research team. The one factor most associated with infection was (drum roll): dry air. At low relative humidity, indoor air was strongly associated with higher infection rates. “When we dry the air out, droplets and skin flakes carrying viruses and bacteria are launched into the air, traveling far and over long periods of time. The microbes that survive this launching tend to be the ones that cause healthcare-associated infections,” said Taylor. “Even worse, in addition to this increased exposure to infectious particles, the dry air also harms our natural immune barriers which protect us from infections."

Since that study was published, there is now more research in peer-reviewed literature observing a link between dry air and viral infections, such as the flu, colds and measles, as well as many bacterial infections, and the National Institutes of Health (NIH) is funding more research. Taylor finds one of the most interesting studies from a team at the Mayo Clinic, which humidified half of the classrooms in a preschool and left the other half alone over three months during the winter. Influenza-related absenteeism in the humidified classrooms was two-thirds lower than in the standard classrooms—a dramatic difference. Taylor says this study is important because its design included a control group: the half of classrooms without humidity-related intervention.

Humidifiers are expensive, but fortunately, there are plenty of free, low-tech ways to humidify rooms. Should we not be talking about this--especially vis-a-vis schools?
www.diynetwork.com/made-and-remade/learn-it/6-ways-to-humidify-your-house-without-using-a-humidifier

[nannynick]

John Campbell has mentioned it several times on his videos.

Humidity in my flat typically is around 60% and has been as high as 78%. The more heating is on and all windows shut it will drop to around 50%.

What is the ideal percentage to keep the virus level low? 60%+?

[WindFlower92]

Stupid question, but is too much humidity a bad thing? My classroom has all windows and door open and no heating on. My weather app says humidity outside today is about 80%, are these conditions okay?

[pastandpresent]

I was used to using humidifier when living outside of uk. But when I used humidifier in uk, it caused so much trouble, mouldy windowsill etc. I think uk is incredibly humid during winter, even with heating on.
Japanese winter is cold but very dry. It's totally opposite here, ime.

[Quarterback11]

Because we are doing our best to bring humidity DOWN to 60%, no need to try and increase it.

Open the windows and the humidity will increase (88% outdoors here today).

[LilyPond2]

@WhiskyTangoFoxtrot I recall reading a theory re meat processing plants that the repeated spraying down of areas causes the virus to aerosolise. So maybe in meat processing plants that phenomenon is outweighing any benefits from humidity.

[WhiskyTangoFoxtrot]

Opening windows is always sensible.

It's happening in schools (threads are beginning about to appear about the need for thermals)

Air conditioned offices and other workplaces are I suppose the risky places?

Thinking of workplaces, how does this theory fit with meat processing plants?

[acerred]

Two windows in my house are permanently open and I always have a window open downstairs when we are in the living room so I think we're probably OK with the amount of rain we get.

[nodogz]

I

[Clareflairmare]

It’s probably not a major issue in houses and schools. They generally are quite humid, but I think it’s a very valid consideration for big office blocks and factories which often don’t have opening windows and have AC systems that dry the air. We should also be requiring large building to improve their air filtration systems. You can now get air filtration that is significantly better at removing viruses including COVID than is standard in many large buildings.

[strictlysocialdistancing]

I think that this really interesting. I live in an exceptionally humid place and rates of transmission have been quite low and where there has been spread it has been inside heated places. Thanks for posting OP

[Guylan]

*sorry forgot to include above at the end the CDC page link www.cdc.gov/coronavirus/2019-ncov/more/scientific-brief-sars-cov-2.html

[Guylan]

parlezvouswronglais, sorry a correction to the above. The CDC don’t cite the figure 10% of droplet respiratory emission is the smaller droplets than can linger in the air. They say it’s uncommon but can happen, usually in enclosed areas when an infected person has been talking for 30 mins or more . Extract from the CDC notice on it below with link to the full notice:

“Airborne transmission of SARS-CoV-2 can occur under special circumstances. Pathogens that are mainly transmitted through close contact (i.e., contact transmission and droplet transmission) can sometimes also be spread via airborne transmission under special circumstances. There are several well-documented examples in which SARS-CoV-2 appears to have been transmitted over long distances or times. These transmission events appear uncommon and have typically involved the presence of an infectious person producing respiratory droplets for an extended time (>30 minutes to multiple hours) in an enclosed space. Enough virus was present in the space to cause infections in people who were more than 6 feet away or who passed through that space soon after the infectious person had left. Circumstances under which airborne transmission of SARS-CoV-2 appears to have occurred include:

Enclosed spaces within which an infectious person either exposed susceptible people at the same time or to which susceptible people were exposed shortly after the infectious person had left the space.
Prolonged exposure to respiratory particles, often generated with expiratory exertion (e.g., shouting, singing, exercising) that increased the concentration of suspended respiratory droplets in the air space.
Inadequate ventilation or air handling that allowed a build-up of suspended small respiratory droplets and particles.
Prevention of COVID-19 by airborne transmission
Existing interventions to prevent the spread of SARS-CoV-2 appear sufficient to address transmission both through close contact and under the special circumstances favorable to potential airborne transmission. Among these interventions, which include social distancing, use of masks in the community, hand hygiene, and surface cleaning and disinfection, ventilation and avoidance of crowded indoor spaces are especially relevant for enclosed spaces, where circumstances can increase the concentration of suspended small droplets and particles carrying infectious virus. At this time, there is no indication of a general community need to use special engineering controls, such as those required to protect against airborne transmission of infections, like measles or tuberculosis, in the healthcare setting.”

[Guylan]

Unless there’s been an aerosol generating procedure it does not hang in the air.

The US CDC have now up on their website that there is good evidence that about 10% of the droplets breathed out (no aerosol generating procedure required) are smaller droplets that can carry much longer than 2 metres and linger in the air. So the larger droplets that generally fall to the ground within 2 metres are predominant but there are some that linger in the air and why ventilation indoors is required as well.

OP thanks for this I did not know there are some studies that suggest humidity can also help.

[LilQueenie]

I've had my windows open night and day since March to dilute any virus particle that may have entered the house. It was mentioned very early on in studies that keeping a good flow of fresh air around would help.

[alexdgr8]

some of the TB patients had to sleep out on the veranda, i remember reading memoirs of nurses brushing the snow off the counterpane in the morning.

but how does all this relate to damp being a bad thing ?

[ParlezVousWronglais]

Covid mostly infects by travelling in droplets from a person’s mouth or nose directly onto the other person. Unless there’s been an aerosol generating procedure it does not hang in the air. In most environments and day to day situations humidity will make very little difference to this.

[TracyBeakerSoYeah]

Well we get told to take babies into a steamy bathroom when they have croup or a constant barking cough & sound a bit wheezy.
Certainly helped my DD as a baby.
Hot water in a bowl with a bit of Vicks or Olbas Oil & you bent over the bowl with a towel over your head & bowl helps an adult with a cold & stuffy nose.
So it makes sense that humidity would help prevent Covid from spreading as much.
Also having good ventilation is key.
In my family sleeping with a window open all year round was the done thing as Great Grandma, Grandparents & parents said fresh air kept you healthy.
In the past TB patients were wheeled out in their beds from the sanatorium wards to the gardens to get a few hours of healthy fresh air.

[Kokeshi123]

Yup, I think I did mention something about humidifying air on a thread last week.

I'm starting a thread on it here to discuss it again, because the thing is, when there is actually pretty good evidence that something can really help reduce spread of the virus in schools, businesses, hospitals, homes etc., and the thing itself is cheap and easy to do, and closing schools and businesses due to unchecked spread of said virus is both difficult and expensive, then I think it is actually worth while thinking about this.

Lockdowns and school closures cost money and education---why not try seizing some low-hanging fruit by doing things that are quick and cheap to do? Other countries have known about the humidification thing for a while. It all feels a bit like the early spring, when a few people here were trying to urge the importance of masks based on the experience of Asian countries, and there was a lot of skepticism.

[Inkpaperstars]

Try living in a small flat with no tumble dryer or utility area. Dry air won't be a problem!

But thank you for the post OP, I was unaware of the thinking on this. For some reason, to a lay person it seems that dry air would be 'cleaner'.

[LilyPond2]

OP, when I click on the last of the links in your OP, I get a message telling me that the website isn't available in my country. (I'm in the UK.) But thank you for posting. I have noticed the issue of humidity crop up in the "Studies Corner" threads and I certainly agree it needs more attention.

[GabriellaMontez]

Totally agree OP. This will be relevant in certain places here eg in an air conditioned office.

[BrightSunshineDay]

The air outside may be humid, but if you have your windows shut and central heating on, the air indoors may still be very dry.

Exactly. I live in a small terrace in Scotland and often have my heating on. The air does get very dry as my sinuses will atest to. I always have bowls of water in every room during the winter months otherwise I wake up with a dry throat and stuffy nose. And yes I open my windows as much as possible but when you have gale force winds and horizontal rain it's not always feasible.

[2bazookas]

In UK, only a minority of domestic homes have (or need) air-conditioning. Even in winter, we don't heat homes to anything like the temperature of many US homes. My home thermostat is set at 19C (68 F) in winter.

We live in Scotland. Rainfall happens all year round, n atural humidifier. I open all windows for at least an hour every day, winter and summer. We sleep with the bedroom windows open all night, all year round. So the air in our house is fresh, and never dry. It's clean and unpolluted, straight off the hills and sea.

[LilyPond2]

I think a lot of the posters dismissing the issue are missing the point. The air outside may be humid, but if you have your windows shut and central heating on, the air indoors may still be very dry.

[HesterShaw1]

Oh I should be fine in my house then. It's made of granite and absorbs moisture like a sponge.

And given the shit, damp state of a lot of UK houses with all those people living together and exhaling more moisture, they should be absolutely fine too.