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Submarines operate in the 1000s of PPM CO2 range and the sailors aboard generally do not experience any ill effects. This was tested and no deficits were found

Submarines operate in the 1000s of PPM CO2 range and the sailors aboard generally do not experience any ill effects. This was tested and no deficits were found even at 15,000 PPM: https://asma.kglmeridian.com/view/journals/amhp/89/6/article-p520.xml https://asma.kglmeridian.com/view/journals/amhp/89/6/article...

brookst 3mo ago
Though that study included a 45 minute acclimation period. Appropriate for submarines, but I wonder what the results would be in the first 1 / 5 / 10 minutes.
- threatripper 3mo ago
  CO2 levels will rise much more slowly to such high levels even in a small room.
Robin_Message 3mo ago
If that study was of submariners, is it possible long-term high-level exposure causes the body to adapt? I am suspicious of 0.1% having a significant effect though, given oxygen is around 20% and we naturally exhale a couple of percent CO2.
- pishpash 3mo ago
  I mean that can't be right, as the body's breathing response is triggered by that amount of CO2 buildup. It's not about what's in the air. It's about what the body can take up. Maybe submariners are self-selected to be more physically fit, e.g. larger heart, lung capacity etc. to compensate.
culturestate 3mo ago
One key difference is that submariners are rigorously trained to operate effectively in less-than-ideal environmental conditions, whereas Bob from accounting probably is not.
w-m 3mo ago
I don't think you can cleanly compare this: In the study, they added CO2 to the room, while keeping O2 at normoxic levels throughout the experiment. In your meeting room, O2 levels will be dropping in lock-step with the CO2-levels rising. It may be the lack of oxygen that leads to drowsiness, not the additional CO2. But it's the CO2 levels that you can measure as a good proxy of overall air quality.
- hahahaa 3mo ago
  O2 is 200000ppm so if co2 goes up 400 to 2000ppm does o2 go down to 198400ppm?
  - fuzzfactor 3mo ago
    Don't neglect the 80% nitrogen which dominates proportionally.
- KerrickStaley 3mo ago
  I don't think this is correct. The concentration of CO2 in air is about 0.04%, whereas the concentration of oxygen is 20%, so the partial pressure of oxygen is about 500x higher. This means that if, for example, 10% of the oxygen in a room spontaneously disappeared, it would be replaced about sqrt(500) = 22x faster through leaks in the room than a 10% spontaneous CO2 increase would dissipate. (This ignores a small effect due to the different density of the two gases). So in practice the oxygen level can never drift meaningfully far from the atmospheric pressure, whereas carbon dioxide easily can because the pressures involved are so low.
  - w-m 3mo ago
    Ok, fair points, including the sister comment, it's likely not a drop in O2 levels. But then why can we see problems with concentration in studies of people in poorly ventilated rooms, but not replicate that when just adding CO2 to normal air? What is the CO2 that we can measure in meeting rooms actually a proxy for?
    - 3mo ago
nok22kon 3mo ago
could be a selection effect at work
dev1ycan 3mo ago
Submarineers also are hand picked due to their great lung capacity...
mppm 3mo ago
... which is entirely unsurprising given that exhaled air is about 50.000 ppm CO2 and can vary by several 10.000s depending on depth and rate of breathing. I actually consider the recent wave of findings that CO2 levels as low as 500-1000 ppm measurably affect cognitive performance and well-being to be a great example of how you can prove literally anything with statistics and a sufficiently small sample size.
amluto 3mo ago
A major confounding factor is everything else in the air. Humans produce lots of different gases, and CO2 is usually a proxy for the overall concentration of our effluent gases. But in a submarine, or in some buildings, there are gas filters (usually carbon, possibly with various modifications) that can remove or destroy some of these gases but have no effect on CO2. So the air in a submarine at 15000ppm CO2 could be very different from the air in a an unventilated room that reaches 15000ppm CO2.
- dr_dshiv 3mo ago
  The first person to deal with this may have been Cornelis Drebbel in 1610 when he deployed the first submarine. With 4 oarsmen submerged in a leaky wooden sub, they’d have too much co2 and too little oxygen. Somehow they were able to stay for hours at a time. Robert Boyle describes Drebbel’s use of a “chymical liquor” to refresh the air. “Paracelſus, indeed, tells us, that "as the ſtomach concocts the aliment, "and makes part of it uſeful to the body, rejecting the other; ſo the "lungs conſume part of the air, and reject the reſt." Whence, according to him, we may ſuppoſe a little vital quinteſſence in the air, which ſerves to refresh and reſtore our vital ſpirits; for which purpoſe, the groſſer, and far greater part of the air, being unſerviceable, it is not ſtrange that an animal ſhould inceſſantly require fresh air. This opinion, indeed, is not abſurd; but it requires to be explain'd and prov'd: beſides, ſome objections may be made to it, from what has been already argued againſt the transmutation of air, into vital ſpirits. Nor is it probable, that the bare want of the generation of the uſual quantity of vital ſpirits, for leſs than one minute, ſhould be able to kill a lively animal, without the help of any external violence. And, upon this ſuppoſition, Cornelius Drebell, is affirm'd, by many credible perſons, to have contrived a veſſel to be row'd under water: for Drebell conceiv'd, that it is not the whole body of the air, but a certain ſpirituous part of it, that fits it for reſpiration; which being ſpent, the remaining groſſer body of the air, is unable to cheriſh the vital flame reſiding in the heart. So that, beſides the mechanical contrivance of his boat, he had a chymical liquor, which, by unſtopping the veſſel wherein it was contain'd, the fumes of it would ſpeedily reſtore to the air, foul'd by reſpiration, ſuch a proportion of vital parts, as would make it again fit for that office; and having made it my buſineſs to learn this ſtrange liquor, his relations conſtantly affirm'd, that Drebell would never diſcloſe it, but to one perſon, who himſelf told me what it was.“ https://sourcelibrary.org/book/philosophical-works-vol-2-boyle/page/6955d3cd28a09ca65927e6f2 https://sourcelibrary.org/book/philosophical-works-vol-2-boy...

brookst 3mo ago

Though that study included a 45 minute acclimation period. Appropriate for submarines, but I wonder what the results would be in the first 1 / 5 / 10 minutes.

threatripper 3mo ago
CO2 levels will rise much more slowly to such high levels even in a small room.

Robin_Message 3mo ago

If that study was of submariners, is it possible long-term high-level exposure causes the body to adapt? I am suspicious of 0.1% having a significant effect though, given oxygen is around 20% and we naturally exhale a couple of percent CO2.

pishpash 3mo ago
I mean that can't be right, as the body's breathing response is triggered by that amount of CO2 buildup. It's not about what's in the air. It's about what the body can take up. Maybe submariners are self-selected to be more physically fit, e.g. larger heart, lung capacity etc. to compensate.

culturestate 3mo ago

One key difference is that submariners are rigorously trained to operate effectively in less-than-ideal environmental conditions, whereas Bob from accounting probably is not.

w-m 3mo ago

I don't think you can cleanly compare this: In the study, they added CO2 to the room, while keeping O2 at normoxic levels throughout the experiment. In your meeting room, O2 levels will be dropping in lock-step with the CO2-levels rising. It may be the lack of oxygen that leads to drowsiness, not the additional CO2. But it's the CO2 levels that you can measure as a good proxy of overall air quality.

hahahaa 3mo ago
O2 is 200000ppm so if co2 goes up 400 to 2000ppm does o2 go down to 198400ppm?
- fuzzfactor 3mo ago
  Don't neglect the 80% nitrogen which dominates proportionally.
KerrickStaley 3mo ago
I don't think this is correct. The concentration of CO2 in air is about 0.04%, whereas the concentration of oxygen is 20%, so the partial pressure of oxygen is about 500x higher. This means that if, for example, 10% of the oxygen in a room spontaneously disappeared, it would be replaced about sqrt(500) = 22x faster through leaks in the room than a 10% spontaneous CO2 increase would dissipate. (This ignores a small effect due to the different density of the two gases). So in practice the oxygen level can never drift meaningfully far from the atmospheric pressure, whereas carbon dioxide easily can because the pressures involved are so low.
- w-m 3mo ago
  Ok, fair points, including the sister comment, it's likely not a drop in O2 levels. But then why can we see problems with concentration in studies of people in poorly ventilated rooms, but not replicate that when just adding CO2 to normal air? What is the CO2 that we can measure in meeting rooms actually a proxy for?
  - 3mo ago

nok22kon 3mo ago

could be a selection effect at work

dev1ycan 3mo ago

Submarineers also are hand picked due to their great lung capacity...

mppm 3mo ago

... which is entirely unsurprising given that exhaled air is about 50.000 ppm CO2 and can vary by several 10.000s depending on depth and rate of breathing. I actually consider the recent wave of findings that CO2 levels as low as 500-1000 ppm measurably affect cognitive performance and well-being to be a great example of how you can prove literally anything with statistics and a sufficiently small sample size.

amluto 3mo ago

A major confounding factor is everything else in the air. Humans produce lots of different gases, and CO2 is usually a proxy for the overall concentration of our effluent gases. But in a submarine, or in some buildings, there are gas filters (usually carbon, possibly with various modifications) that can remove or destroy some of these gases but have no effect on CO2. So the air in a submarine at 15000ppm CO2 could be very different from the air in a an unventilated room that reaches 15000ppm CO2.

dr_dshiv 3mo ago
The first person to deal with this may have been Cornelis Drebbel in 1610 when he deployed the first submarine. With 4 oarsmen submerged in a leaky wooden sub, they’d have too much co2 and too little oxygen. Somehow they were able to stay for hours at a time. Robert Boyle describes Drebbel’s use of a “chymical liquor” to refresh the air. “Paracelſus, indeed, tells us, that "as the ſtomach concocts the aliment, "and makes part of it uſeful to the body, rejecting the other; ſo the "lungs conſume part of the air, and reject the reſt." Whence, according to him, we may ſuppoſe a little vital quinteſſence in the air, which ſerves to refresh and reſtore our vital ſpirits; for which purpoſe, the groſſer, and far greater part of the air, being unſerviceable, it is not ſtrange that an animal ſhould inceſſantly require fresh air. This opinion, indeed, is not abſurd; but it requires to be explain'd and prov'd: beſides, ſome objections may be made to it, from what has been already argued againſt the transmutation of air, into vital ſpirits. Nor is it probable, that the bare want of the generation of the uſual quantity of vital ſpirits, for leſs than one minute, ſhould be able to kill a lively animal, without the help of any external violence. And, upon this ſuppoſition, Cornelius Drebell, is affirm'd, by many credible perſons, to have contrived a veſſel to be row'd under water: for Drebell conceiv'd, that it is not the whole body of the air, but a certain ſpirituous part of it, that fits it for reſpiration; which being ſpent, the remaining groſſer body of the air, is unable to cheriſh the vital flame reſiding in the heart. So that, beſides the mechanical contrivance of his boat, he had a chymical liquor, which, by unſtopping the veſſel wherein it was contain'd, the fumes of it would ſpeedily reſtore to the air, foul'd by reſpiration, ſuch a proportion of vital parts, as would make it again fit for that office; and having made it my buſineſs to learn this ſtrange liquor, his relations conſtantly affirm'd, that Drebell would never diſcloſe it, but to one perſon, who himſelf told me what it was.“ https://sourcelibrary.org/book/philosophical-works-vol-2-boyle/page/6955d3cd28a09ca65927e6f2 https://sourcelibrary.org/book/philosophical-works-vol-2-boy...