Comment by a1371
3 days ago
I have a degree in building science, so maybe I can chime in. Note of caution: you will find yourself breathing heavily after reading this. It's normal.
We do a terrible job at ventilating our indoor spaces. As a cave-dwelling species our brains are quite comfortable with tuning out bad smells and tolerating stale air -- but the effect of it on our mode and well-being is almost immediate. You don't notice the effect, but it is there.
That's why they tell you if the airplane's cabin depressurizes, put on your own mask first. People who don't manage to that quickly enough their eyes stay open, they don't even feel anything is wrong, but they are physically unable to put on their masks until they pass out.
If not eating proper food kills you in 3 weeks, not breathing proper air kills you in 3 minutes. Yet, people spend thousands of dollars on a new diet, but have no idea what kind of stuff are going into their lungs.
The situation is not life and death. It's feeling nice versus feeling low. People end up with indoor air that is often stale and full of volatile compounds. We often make it worse by using essential oil diffusers and not using the vent hood when cooking.
When you do a breathing exercise, all of a sudden you are giving your starving brain a dose of what it could be like. When you have a walk in the nature, you do the same.
So yes, breathing exercises are great, but it's even better if we fix our indoor environments to feel great at all times.
The FAA puts on workshops around the country with a portable reduced oxygen training enclosure (PROTE). You sit in the enclosure (looks like a sealed vinyl tent), they reduce the available oxygen and simulate hypoxia. You've got a clipboard with some basic math problems, a maze to trace, etc. The trainers continually engage you for 3-4 minutes as you slowly get more hypoxic.
As a pilot, it was eye opening to see first-hand what happens to me when experiencing hypoxia. The trainers were talking to me, and I was replying, but was unable to tell them what 17 minus 4.5 was. My pulse oximeter was in the low 70s. Two sips of oxygen from a mask and I was right back to normal. I learned that my first symptom (the clue that something is really going wrong in the cockpit) is tunnel vision.
Destin from Smarter Every Day (YouTube) has a wonderful video demonstrating this effect [0]. I’d recommend watching the whole thing, but you can see how much of an effect it has starting around the 6:00 mark.
[0] https://youtu.be/kUfF2MTnqAw?si=LRDtSJSy7jiTIpzy
How do you measure indoor air quality? CO2 levels?
Our current understanding is that no amount of CO2 is dangerous as long as everything else is fine, but in reality CO2 acts like the canary in the coal mine. When it climbs, it shows accumulation of stuff you don't want to deal with.
Measurement of compounds is best done using a monitor like Aranet, but incidental bumps in different values don't mean much. Long trends matter. If Radon is an issue in your region, a detector for that. Mold testing kits are readily available in market indicating moisture issues and you can get lead and other hazmat testing done diy/professionally
You say, "Our current understanding is that no amount of CO2 is dangerous as long as everything else is fine," but I don't think that is correct. Like any other non-oxygen gas, carbon dioxide is an asphyxiant, and it is routinely used as such to kill rats, but it has significant toxicity even at much lower levels. NIOSH says:
> Signs of intoxication have been produced by a 30-minute exposure at 50,000 ppm [Aero 1953], and a few minutes exposure at 70,000 to 100,000 ppm produces unconsciousness [Flury and Zernik 1931]. It has been reported that submarine personnel exposed continuously at 30,000 ppm were only slightly affected, provided the oxygen content of the air was maintained at normal concentrations [Schaefer 1951]. It has been reported that 100,000 ppm is the atmospheric concentration immediately dangerous to life [AIHA 1971] and that exposure to 100,000 ppm for only a few minutes can cause loss of consciousness [Hunter 1975].
(https://www.cdc.gov/niosh/idlh/124389.html)
100,000 ppm is 10%, so at that point the carbon dioxide has reduced the oxygen in your air from 21% to 19%, far from asphyxiation conditions.
Even at much lower levels, carbon dioxide can produce drowsiness and mental impairment.
On the other hand, reaching 5% or 10% carbon dioxide by oxidizing carbon with oxygen from the air, for example by breathing or having a fire, will reduce the oxygen content of the air to an extent that is more dangerous than the carbon monoxide. So carbon dioxide toxicity is generally not the thing to worry about with respect to indoor air safety. But that doesn't mean it's not real.
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Aren't there several studies showing markedly worse performance at tasks at CO2 levels easily reached in a home? Or you just mean you won't die as the meaning of not dangerous?
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Buy an air quality monitor. There are tons on Amazon. Here’s an example: https://www.amazon.com/dp/B0DZHJSQ7Z/
People seem fixated on measuring CO2 specifically and often purchase expensive sensors ($$+) or devices ($$$) to measure CO2 levels.
There are inexpensive sensors ($) that detect a variety of VOCs but cannot distinguish between them and CO2. They'll never give you exact concentrations but they are consistent, broad spectrum, and will alert you of change. IMO these are a better option.
I'ver heard the Aranet4 is quite good for this but haven't yet been able to justify buying one. I do try to open windows frequently, though.
I don't get why they're so expensive. You can buy the ndir co2 sensor on AliExpress for around $10. And yet they want $180 for that thing. And measuring humidity and barometric pressure is a component that costs $4 or $5 for you or I to buy.
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Both particle measures and co2 sensors are somewhat affordable especially if buying raw sensors.
The up shot of it is ventilate frequently and dry heat cooking that browns anything (think steak in pan) releases a shit ton of particle so hood and open window
Measure VOCs, PM2.5 particles, and CO2
Sounds like you’re just making the argument for moving to the wet tropics