13 ms·

From the article: "It is not known exactly what fraction of infections could be prevented if all building and transport ventilation systems on the planet were i

From the article: "It is not known exactly what fraction of infections could be prevented if all building and transport ventilation systems on the planet were ideal (in terms of controlling airborne infections), or the cost of design and retrofitting to make them ideal." I think this is the key question. Surely better ventilation would have prevented some infections in the covid pandemic. But how many? And to decide that we need not just manifestos by civil engineers (like this article) but convincing research results, probably in collaboration with people who actually know some things about viruses as well. And without it, could organizations like the WHO or CDC have plausibly recommended building upgrades?

zargon 5y ago
The WHO and CDC have had their head in the sand for 60 years when it comes to airborne pathogens. They have only acknowledged aerosol transmission of covid in the last couple weeks. It was physicists who had to figure out why they were domatically denying reality. https://www.wired.com/story/the-teeny-tiny-scientific-screwup-that-helped-covid-kill/ https://www.wired.com/story/the-teeny-tiny-scientific-screwu...
- ddxxdd 5y ago
  Apparently the CDC has yet to catch up to 19th century physics. The physics of small particles moving in the air ("Brownian motion") was completely figured out by Einstein back in 1905. Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne.
  - techdragon 5y ago
    The thing about medicine is they like to test. Theory and simulation are nice but it’s just not medicine and therefore not suitable for a doctor to tell to someone as “medical advice” with all of the legal burden of malpractice that the term entails. “What if I’m wrong?” is a question that keeps good doctors awake at night and bad doctors have forgotten to ask themselves… when this kind of question weighs on you, it’s natural human behaviour to become more cautious, to become risk averse and question the validity of newly presented information due to the potential that regardless of if their current understanding is wrong, there’s no inherent guarantee that the new information is any less wrong. And so medicine is understandably a slow moving science, and the practice of medicine moves even slower as it represents the slow filtration of the cutting edge of medicine the science, through a complex web of human interaction. Which with a dash of “social capital” theory, makes it easy to see why we have unfortunately often ignored sound advice like this. The mistaken assumptions of people viewing a person who’s expertise bridges two disparate fields, as being unable to understand things as deeply, clearly or fully, as the people dedicated to just one of those fields.
    - svantana 5y ago
      I can see your point, but isn't the WHO tweeting “FACT: #COVID19 is NOT airborne.” an example of the opposite? They made a hard assertion without any clear proof to back it up.
      - taxicabjesus 5y ago
        Hmm? interesting. Here's the offending tweet: FACT: #COVID19 is NOT airborne. The #coronavirus is mainly transmitted through droplets generated when an infected person coughs, sneezes or speaks. To protect yourself: -keep 1m distance from others -disinfect surfaces frequently -wash/rub your hands -avoid touching your Eyes Nose Mouth - https://twitter.com/who/status/1243972193169616898 https://twitter.com/who/status/1243972193169616898 The WHO gave a lot of bad advice. Some say that it was intentionally misleading. Promoting ventilation as a reasonable treatment for the initial stages of covid-19 was the worst possible advice to give front-line medical practitioners who didn't know what they were dealing with. We now know that the fecal-aerosol route of transmission is very important. Forbes has a recent piece about the fecal-oral/aerosol route: https://www.forbes.com/sites/williamhaseltine/2021/03/22/preventing-fecal-oral-and-fecal-aerosol-transmission-of-covid-19/ https://www.forbes.com/sites/williamhaseltine/2021/03/22/pre... Another tweet by ... someone was about how the masks effectively aerosolize droplets. Keeping bathrooms open but requiring face coverings was an exercise in futility. In the case of COVID-19, the WHO seems to have implemented #PrasadsLaw [0]. "Prasad’s Law: Medical goods and services that concentrate wealth can be paid for; medical goods and services that disperse wealth are “unaffordable.”" [0] https://news.ycombinator.com/item?id=21728864 https://news.ycombinator.com/item?id=21728864
        rhodozelia 5y ago
        Farts are deadly now?
  - sandworm101 5y ago
    >> Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne. How long it remains airborne is beside the point. Does that physics grad know how long/if the virus can survive once it dries up? Do they know how long it will survive exposure to light? Do then know whether the virus can cling to dust particles? Even brownian motion is only half the story. Does the physics grad understand airflow in office spaces? Do they understand how fast air moves when a person coughs? How much turbulence is caused by opening an office door? Plenty of things can stay airborne for extended periods because of aerodynamics without regard to brownian motion (snow/rain/dust/salt etc). That physics grad better come with minors in aerodynamics, kinesiology, microbiology ... even some basic meteorology would be helpful.
    - Enginerrrd 5y ago
      As an civil / environmental engineer, I can assure you that particle size and average settling time is INCREDIBLY important to consider and will cover basically all of your supposed edge cases to the point of being statistically irrelevant. You would handle those edge cases by simply including a safety factor in the required residence time of the average particle within the system considered (or equivalently, you'd specify a certain log removal of pathogens). The end result of all your edge cases that you seem to think are so important is something like: "Ok, 1 in 100,000 may still get sick with this design. Good enough." You can make the same arguments for drinking water, and yet, as long as you follow the rules, it is unbelievably safe, despite the fact that no one gave a shit about turbulence along the baffles in the treatment tank.
  - Izkata 5y ago
    Per that Wired article, it was intentionally ignored when the first virus-related research came up in the 1940s because it was too close to the discredited miasma theory. > Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne. This is also in the article, known research from decades ago. Social distancing is in fact based on a misunderstanding and conflation of a few things in that early research.
- loopz 5y ago
  Good to expose such expert arrogance.
- newsbinator 5y ago
  > EARLY ONE MORNING, Linsey Marr tiptoed to her dining room table, slipped on a headset, and fired up Zoom. On her computer screen, dozens of familiar faces began to appear. She also saw a few people she didn’t know It’s really hard for me to read a WIRED article for information. I mean I realize that’s not what it’s there for but it takes forever to get into the content of the article.
  - c7DJTLrn 5y ago
    Nails on chalkboard.
  - bellyfullofbac 5y ago
    Hear hear. Maybe Wired should talk about the coffee she's sipping, made from beans harvested on the south coast of Java, where there is a legend of a queen who drowned...
    - andi999 5y ago
      I need more detail... what happened to the queens relatives.
      - K0balt 5y ago
        Forget the relatives, where did those BUTONS on her shoes come from!
    - tengbretson 5y ago
      The important thing was that she had an onion on her belt, which was the style at the time. Now, to take the ferry cost a nickel, and in those days, nickels had pictures of bumblebees on 'em. Give me five bees for a quarter, you'd say.
  - Reason077 5y ago
    > "it takes forever to get into the content of the article." I've found this is the style of American long-format journalism in general. Just look at something like The New Yorker: not to dispute the quality of their writing, but the word counts certainly skew high. Articles in comparable British publications tend to be a lot more succinct.
- SideburnsOfDoom 5y ago
  This seems closely related, actually: Wired: EARLY ONE MORNING, Linsey Marr... OP article: A paradigm shift to combat indoor respiratory infection ... Linsey C. Marr (in the author list) Wired: . At one point, Lidia Morawska, OP Article: Lidia Morawska (first listed author)
- renaudg 5y ago
  Here's a fascinating Twitter thread about the history of aerosol transmission denial, going back to the early 20th century : https://twitter.com/jljcolorado/status/1391111720526024708?s=20 https://twitter.com/jljcolorado/status/1391111720526024708?s... It's 100 tweets long, may be more readable here : https://threadreaderapp.com/thread/1391111720526024708.html https://threadreaderapp.com/thread/1391111720526024708.html
  - deleted 5y ago
    [deleted]
- jxramos 5y ago
  that's fascinating, are CDC and WHO officials even practicing physicians? Would that have helped any?
londons_explore 5y ago
I would put money on COVID not happening at all if all buildings had 10 air refreshes per hour, and that air either coming from the outdoors or going through a HEPA filter. I would guess an analysis of workplace COVID rates would see a strong correlation between workplaces with and without filtration in their AC systems.
- loopz 5y ago
  The highest infection rates are still short range though. This, combined with being a new virus would still be similar to today.
  - londons_explore 5y ago
    Short range could be explained by airflow rates in most buildings being near nil. Someone talks in one spot, and pathogens hang around that spot in the air for many minutes. With say 10 air changes per hour (injecting at the ceiling and extraction at the floor), and a 3m high building, you can expect airflow downwards at about 1 cm per second. That means there is perhaps only a 30 second window for a particular pathogen to hit someone else's nose before being pulled to below face level. It's not nil, but I think that would lower transmission rates by a sufficient factor for COVID (and many other diseases) to become extinct.
- hasmanean 5y ago
  There’s a saying, earthquakes don’t kill people—buildings kill people when they collapse. In the open air on a grassland, covid won’t kill a population. The design of our hermetically sealed buildings is what’s killing us. Back in the 1970s the air outside was full of lead and smog, so the safest thing too was completely seal all office buildings. Today the air inside probably contains more hydrocarbons (from volatile organic compounds offgassing from carpets and furniture) so the best thing to do is vent air to the outside and keep the windows open (assuming you live in a mild climate) Of course, that flies in the face of all efforts to make things green…which involve better insulation, sealing windows against leaks, more air filtration systems and etc. Here in Canada the temperature drops like 5 or 10 degrees when you walk into a forest. I’ve stepped into a traditional mud hut and experienced a similar cooling effect. The common denominator is that both environments have a high surface area compared to say concrete. This acts as an efficient radiator so that when water to evaporates it removes heat. In low humidity climates this is one way to reduce cooling demands. Beyond that if we cool micro zones or interstate cooling into clothing itself through hoses or something that might be the next step in efficiency…until it gives birth to the next problem.
ur-whale 5y ago
There is a "law of unintended effects" question as well: if we were to live - and presumably grow up - in such a sanitized environment, what would happen to our immune system. There's a sizeable chance it would be extremely weak and that'd we'd be incapable of resisting many disease on our own and therefore would become completely dependent on the air cleaning infrastructure.
- f6v 5y ago
  You still eat fresh fruits and vegetables, touch the surfaces on your way to work etc. There’re countless pathogens everywhere. So I guess we would be fine? You’re right that our immune system didn’t evolve to be in a sterile environment. But we also weren’t meant to be that close to that many humans.
  - ur-whale 5y ago
    >So I guess we would be fine? Can you catch airborne respiratory diseases from eating fruit? What I'm saying is: we run the risk of never being able to go outside again if we eliminate all airborne pathogens.
    - Enginerrrd 5y ago
      Not to worry, people will still have children, and I assure you, they'll still go out into the world and lick the doorknobs/each other and get you sick so you can bring it to work.
    - falseprofit 5y ago
      Are you suggesting that bringing more air from outdoors into our indoors environments will cause us to lose our ability to tolerate outdoors air?
    - f6v 5y ago
      > Can you catch airborne respiratory diseases from eating fruit? I'm willing to speculate that exposing our immune system to surface pathogens helps deal with airborne pathogens.
daniellarusso 5y ago
This is the Ben Franklin / John Adams debate when they shared a small room together overnight with one window. “When Adams explained that he didn’t want to catch an illness from the cold night air, Franklin countered that the air in their room was even worse.” https://www.mentalfloss.com/article/54169/time-ben-franklin-and-john-adams-shared-bed https://www.mentalfloss.com/article/54169/time-ben-franklin-...
- yosito 5y ago
  This reminds me of an argument I had with a friend in October. When the weather got cold, I only wanted to socialize with our small group of friends outside because the open air was safer, but she only wanted to socialize inside because she thought being outside in the cold would make her catch COVID.
- Joker_vD 5y ago
  Miasma theory rears its ugly head once again: https://en.wikipedia.org/wiki/Miasma_theory#Contagionism_versus_miasmatism https://en.wikipedia.org/wiki/Miasma_theory#Contagionism_ver... The night air is dangerous, close those windows before you go to sleep!
  - goldenkey 5y ago
    Miasma was a perfectly good theory and if anything, is obviously true innately. Bad smelling air from urine, shit, festering corpses and the like, was often laden with viruses, bacteria, and noxious chemical fumes. Sure, plenty of diseases are not airborne but air that smells like shit isn't exactly a boon to be inhaling. There is a non zero chance of getting sick from noxious air.
    - Joker_vD 5y ago
      Yes, it's "obviously true" because of the confounding factors: bad air tends to go hand in hand with dirty water, contaminated food, and infection-carrying insects. Neither cholera, malaria, typhoid nor plague are airborne, and yet their causes were ascribed to miasmata.
CoastalCoder 5y ago
I agree. Changing the building codes' ventilation requirements will cost time and money. And the resulting designs are potentially louder, bulkier, and less energy-efficient. Hopefully we'll make those changes if and only if doing so brings significant health benefits.
heisenbit 5y ago
A considerable number of deaths could be prevented. There are models that show that masks helped to curb spread of flu so well that excess deaths due to Covid in some places became negative.
clairity 5y ago
yes, and while it might have helped at the margin, it's frankly naive to think that we'd have largely avoided this pandemic had we just had better indoor air circulation. it's an analytical solution (so irresistable to engineers, mathematicians, and physicists!) to a complicated and stochastic set of behavioral patterns, that people want to be close to each other indoors for highly complex and very substantive social reasons (not to mention the intricate contraints the virus faces to transmit). transmission happens closely face-to-face indoors, and in light of that, folks aren't going to want to sit together for very long in an airstream strong enough and comprehensive enough to deflect and capture potential virus particles everywhere just to chat and enjoy each other's company for a bit. while most mask usage in practice has been completely useless (like double-masking or wearing them outside), the one place where masks make real sense is between two faces close to each other emitting exhaust indoors. if we had just relentlessly kept to this one crucial scenario in our mask messaging (and simply distancing everywhere else inside), we'd have had much better and more targeted mitigation, with dramatically fewer downsides to our social and economic lives. and to boot, that avoids trying to make extraordinarily costly upgrades to every hvac system in the world for marginal benefit.
radu_floricica 5y ago
It's the theoretical key question. The practical one is more like "how's the cost benefit curve looking like, especially in the beginning?". My personal completely unscientific musings on the topic ended with buying and cutting up a couple of vacuum cleaner hepa filters, thus obtaining a shocking quantity of filter cloth, which then can simply be taped over the standard AC mesh filter. AFAIK, "hepa" ACs don't even cover the full surface - they just have a patch of hepa, which just ensures the air inside gets circulated through it eventually - being recirculated, there's not that much of a hurry. I'd recommend low-end filters, you don't want to remove virus particles but much larger clusters of virus+saliva. So personally I'm guessing a rather high impact for very low cost / low effort changes.

zargon 5y ago

The WHO and CDC have had their head in the sand for 60 years when it comes to airborne pathogens. They have only acknowledged aerosol transmission of covid in the last couple weeks. It was physicists who had to figure out why they were domatically denying reality. https://www.wired.com/story/the-teeny-tiny-scientific-screwup-that-helped-covid-kill/ https://www.wired.com/story/the-teeny-tiny-scientific-screwu...

ddxxdd 5y ago
Apparently the CDC has yet to catch up to 19th century physics. The physics of small particles moving in the air ("Brownian motion") was completely figured out by Einstein back in 1905. Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne.
- techdragon 5y ago
  The thing about medicine is they like to test. Theory and simulation are nice but it’s just not medicine and therefore not suitable for a doctor to tell to someone as “medical advice” with all of the legal burden of malpractice that the term entails. “What if I’m wrong?” is a question that keeps good doctors awake at night and bad doctors have forgotten to ask themselves… when this kind of question weighs on you, it’s natural human behaviour to become more cautious, to become risk averse and question the validity of newly presented information due to the potential that regardless of if their current understanding is wrong, there’s no inherent guarantee that the new information is any less wrong. And so medicine is understandably a slow moving science, and the practice of medicine moves even slower as it represents the slow filtration of the cutting edge of medicine the science, through a complex web of human interaction. Which with a dash of “social capital” theory, makes it easy to see why we have unfortunately often ignored sound advice like this. The mistaken assumptions of people viewing a person who’s expertise bridges two disparate fields, as being unable to understand things as deeply, clearly or fully, as the people dedicated to just one of those fields.
  - svantana 5y ago
    I can see your point, but isn't the WHO tweeting “FACT: #COVID19 is NOT airborne.” an example of the opposite? They made a hard assertion without any clear proof to back it up.
    - taxicabjesus 5y ago
      Hmm? interesting. Here's the offending tweet: FACT: #COVID19 is NOT airborne. The #coronavirus is mainly transmitted through droplets generated when an infected person coughs, sneezes or speaks. To protect yourself: -keep 1m distance from others -disinfect surfaces frequently -wash/rub your hands -avoid touching your Eyes Nose Mouth - https://twitter.com/who/status/1243972193169616898 https://twitter.com/who/status/1243972193169616898 The WHO gave a lot of bad advice. Some say that it was intentionally misleading. Promoting ventilation as a reasonable treatment for the initial stages of covid-19 was the worst possible advice to give front-line medical practitioners who didn't know what they were dealing with. We now know that the fecal-aerosol route of transmission is very important. Forbes has a recent piece about the fecal-oral/aerosol route: https://www.forbes.com/sites/williamhaseltine/2021/03/22/preventing-fecal-oral-and-fecal-aerosol-transmission-of-covid-19/ https://www.forbes.com/sites/williamhaseltine/2021/03/22/pre... Another tweet by ... someone was about how the masks effectively aerosolize droplets. Keeping bathrooms open but requiring face coverings was an exercise in futility. In the case of COVID-19, the WHO seems to have implemented #PrasadsLaw [0]. "Prasad’s Law: Medical goods and services that concentrate wealth can be paid for; medical goods and services that disperse wealth are “unaffordable.”" [0] https://news.ycombinator.com/item?id=21728864 https://news.ycombinator.com/item?id=21728864
      - rhodozelia 5y ago
        Farts are deadly now?
- sandworm101 5y ago
  >> Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne. How long it remains airborne is beside the point. Does that physics grad know how long/if the virus can survive once it dries up? Do they know how long it will survive exposure to light? Do then know whether the virus can cling to dust particles? Even brownian motion is only half the story. Does the physics grad understand airflow in office spaces? Do they understand how fast air moves when a person coughs? How much turbulence is caused by opening an office door? Plenty of things can stay airborne for extended periods because of aerodynamics without regard to brownian motion (snow/rain/dust/salt etc). That physics grad better come with minors in aerodynamics, kinesiology, microbiology ... even some basic meteorology would be helpful.
  - Enginerrrd 5y ago
    As an civil / environmental engineer, I can assure you that particle size and average settling time is INCREDIBLY important to consider and will cover basically all of your supposed edge cases to the point of being statistically irrelevant. You would handle those edge cases by simply including a safety factor in the required residence time of the average particle within the system considered (or equivalently, you'd specify a certain log removal of pathogens). The end result of all your edge cases that you seem to think are so important is something like: "Ok, 1 in 100,000 may still get sick with this design. Good enough." You can make the same arguments for drinking water, and yet, as long as you follow the rules, it is unbelievably safe, despite the fact that no one gave a shit about turbulence along the baffles in the treatment tank.
- Izkata 5y ago
  Per that Wired article, it was intentionally ignored when the first virus-related research came up in the 1940s because it was too close to the discredited miasma theory. > Given a virus' size and weight, it should be trivial for a physics graduate student to simulate how long it will be airborne. This is also in the article, known research from decades ago. Social distancing is in fact based on a misunderstanding and conflation of a few things in that early research.
loopz 5y ago
Good to expose such expert arrogance.
newsbinator 5y ago
> EARLY ONE MORNING, Linsey Marr tiptoed to her dining room table, slipped on a headset, and fired up Zoom. On her computer screen, dozens of familiar faces began to appear. She also saw a few people she didn’t know It’s really hard for me to read a WIRED article for information. I mean I realize that’s not what it’s there for but it takes forever to get into the content of the article.
- c7DJTLrn 5y ago
  Nails on chalkboard.
- bellyfullofbac 5y ago
  Hear hear. Maybe Wired should talk about the coffee she's sipping, made from beans harvested on the south coast of Java, where there is a legend of a queen who drowned...
  - andi999 5y ago
    I need more detail... what happened to the queens relatives.
    - K0balt 5y ago
      Forget the relatives, where did those BUTONS on her shoes come from!
  - tengbretson 5y ago
    The important thing was that she had an onion on her belt, which was the style at the time. Now, to take the ferry cost a nickel, and in those days, nickels had pictures of bumblebees on 'em. Give me five bees for a quarter, you'd say.
- Reason077 5y ago
  > "it takes forever to get into the content of the article." I've found this is the style of American long-format journalism in general. Just look at something like The New Yorker: not to dispute the quality of their writing, but the word counts certainly skew high. Articles in comparable British publications tend to be a lot more succinct.
SideburnsOfDoom 5y ago
This seems closely related, actually: Wired: EARLY ONE MORNING, Linsey Marr... OP article: A paradigm shift to combat indoor respiratory infection ... Linsey C. Marr (in the author list) Wired: . At one point, Lidia Morawska, OP Article: Lidia Morawska (first listed author)
renaudg 5y ago
Here's a fascinating Twitter thread about the history of aerosol transmission denial, going back to the early 20th century : https://twitter.com/jljcolorado/status/1391111720526024708?s=20 https://twitter.com/jljcolorado/status/1391111720526024708?s... It's 100 tweets long, may be more readable here : https://threadreaderapp.com/thread/1391111720526024708.html https://threadreaderapp.com/thread/1391111720526024708.html
- deleted 5y ago
  [deleted]
jxramos 5y ago
that's fascinating, are CDC and WHO officials even practicing physicians? Would that have helped any?

londons_explore 5y ago

I would put money on COVID not happening at all if all buildings had 10 air refreshes per hour, and that air either coming from the outdoors or going through a HEPA filter. I would guess an analysis of workplace COVID rates would see a strong correlation between workplaces with and without filtration in their AC systems.

loopz 5y ago
The highest infection rates are still short range though. This, combined with being a new virus would still be similar to today.
- londons_explore 5y ago
  Short range could be explained by airflow rates in most buildings being near nil. Someone talks in one spot, and pathogens hang around that spot in the air for many minutes. With say 10 air changes per hour (injecting at the ceiling and extraction at the floor), and a 3m high building, you can expect airflow downwards at about 1 cm per second. That means there is perhaps only a 30 second window for a particular pathogen to hit someone else's nose before being pulled to below face level. It's not nil, but I think that would lower transmission rates by a sufficient factor for COVID (and many other diseases) to become extinct.
hasmanean 5y ago
There’s a saying, earthquakes don’t kill people—buildings kill people when they collapse. In the open air on a grassland, covid won’t kill a population. The design of our hermetically sealed buildings is what’s killing us. Back in the 1970s the air outside was full of lead and smog, so the safest thing too was completely seal all office buildings. Today the air inside probably contains more hydrocarbons (from volatile organic compounds offgassing from carpets and furniture) so the best thing to do is vent air to the outside and keep the windows open (assuming you live in a mild climate) Of course, that flies in the face of all efforts to make things green…which involve better insulation, sealing windows against leaks, more air filtration systems and etc. Here in Canada the temperature drops like 5 or 10 degrees when you walk into a forest. I’ve stepped into a traditional mud hut and experienced a similar cooling effect. The common denominator is that both environments have a high surface area compared to say concrete. This acts as an efficient radiator so that when water to evaporates it removes heat. In low humidity climates this is one way to reduce cooling demands. Beyond that if we cool micro zones or interstate cooling into clothing itself through hoses or something that might be the next step in efficiency…until it gives birth to the next problem.

ur-whale 5y ago

There is a "law of unintended effects" question as well: if we were to live - and presumably grow up - in such a sanitized environment, what would happen to our immune system. There's a sizeable chance it would be extremely weak and that'd we'd be incapable of resisting many disease on our own and therefore would become completely dependent on the air cleaning infrastructure.

f6v 5y ago
You still eat fresh fruits and vegetables, touch the surfaces on your way to work etc. There’re countless pathogens everywhere. So I guess we would be fine? You’re right that our immune system didn’t evolve to be in a sterile environment. But we also weren’t meant to be that close to that many humans.
- ur-whale 5y ago
  >So I guess we would be fine? Can you catch airborne respiratory diseases from eating fruit? What I'm saying is: we run the risk of never being able to go outside again if we eliminate all airborne pathogens.
  - Enginerrrd 5y ago
    Not to worry, people will still have children, and I assure you, they'll still go out into the world and lick the doorknobs/each other and get you sick so you can bring it to work.
  - falseprofit 5y ago
    Are you suggesting that bringing more air from outdoors into our indoors environments will cause us to lose our ability to tolerate outdoors air?
  - f6v 5y ago
    > Can you catch airborne respiratory diseases from eating fruit? I'm willing to speculate that exposing our immune system to surface pathogens helps deal with airborne pathogens.

daniellarusso 5y ago

This is the Ben Franklin / John Adams debate when they shared a small room together overnight with one window. “When Adams explained that he didn’t want to catch an illness from the cold night air, Franklin countered that the air in their room was even worse.” https://www.mentalfloss.com/article/54169/time-ben-franklin-and-john-adams-shared-bed https://www.mentalfloss.com/article/54169/time-ben-franklin-...

yosito 5y ago
This reminds me of an argument I had with a friend in October. When the weather got cold, I only wanted to socialize with our small group of friends outside because the open air was safer, but she only wanted to socialize inside because she thought being outside in the cold would make her catch COVID.
Joker_vD 5y ago
Miasma theory rears its ugly head once again: https://en.wikipedia.org/wiki/Miasma_theory#Contagionism_versus_miasmatism https://en.wikipedia.org/wiki/Miasma_theory#Contagionism_ver... The night air is dangerous, close those windows before you go to sleep!
- goldenkey 5y ago
  Miasma was a perfectly good theory and if anything, is obviously true innately. Bad smelling air from urine, shit, festering corpses and the like, was often laden with viruses, bacteria, and noxious chemical fumes. Sure, plenty of diseases are not airborne but air that smells like shit isn't exactly a boon to be inhaling. There is a non zero chance of getting sick from noxious air.
  - Joker_vD 5y ago
    Yes, it's "obviously true" because of the confounding factors: bad air tends to go hand in hand with dirty water, contaminated food, and infection-carrying insects. Neither cholera, malaria, typhoid nor plague are airborne, and yet their causes were ascribed to miasmata.

CoastalCoder 5y ago

I agree. Changing the building codes' ventilation requirements will cost time and money. And the resulting designs are potentially louder, bulkier, and less energy-efficient. Hopefully we'll make those changes if and only if doing so brings significant health benefits.

heisenbit 5y ago

A considerable number of deaths could be prevented. There are models that show that masks helped to curb spread of flu so well that excess deaths due to Covid in some places became negative.

clairity 5y ago

yes, and while it might have helped at the margin, it's frankly naive to think that we'd have largely avoided this pandemic had we just had better indoor air circulation. it's an analytical solution (so irresistable to engineers, mathematicians, and physicists!) to a complicated and stochastic set of behavioral patterns, that people want to be close to each other indoors for highly complex and very substantive social reasons (not to mention the intricate contraints the virus faces to transmit). transmission happens closely face-to-face indoors, and in light of that, folks aren't going to want to sit together for very long in an airstream strong enough and comprehensive enough to deflect and capture potential virus particles everywhere just to chat and enjoy each other's company for a bit. while most mask usage in practice has been completely useless (like double-masking or wearing them outside), the one place where masks make real sense is between two faces close to each other emitting exhaust indoors. if we had just relentlessly kept to this one crucial scenario in our mask messaging (and simply distancing everywhere else inside), we'd have had much better and more targeted mitigation, with dramatically fewer downsides to our social and economic lives. and to boot, that avoids trying to make extraordinarily costly upgrades to every hvac system in the world for marginal benefit.

radu_floricica 5y ago

It's the theoretical key question. The practical one is more like "how's the cost benefit curve looking like, especially in the beginning?". My personal completely unscientific musings on the topic ended with buying and cutting up a couple of vacuum cleaner hepa filters, thus obtaining a shocking quantity of filter cloth, which then can simply be taped over the standard AC mesh filter. AFAIK, "hepa" ACs don't even cover the full surface - they just have a patch of hepa, which just ensures the air inside gets circulated through it eventually - being recirculated, there's not that much of a hurry. I'd recommend low-end filters, you don't want to remove virus particles but much larger clusters of virus+saliva. So personally I'm guessing a rather high impact for very low cost / low effort changes.