i see a lot of posts about bad air situations re: CO2 levels but none of them seem to actually explain what it does that's so bad so like. does anyone have a good primer on what actually happens when you breathe in high CO2 air both in a long term and short term sense?
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in reply to @ivym's post:
I've seen CO2 concentration as a metric for air circulation in an indoor area, used for understanding covid risk there. (e.g. this indoor space has X ppm CO2 higher than what's outside, meaning I'm breathing that much more re-breathed air)
Really high, prolonged CO2 can make you drowsy and headache and isn't great for you. And then like most gasses, at super high concentrations you could asphyxiate.
see my problem is that there are always vagaries referred to with phrases like "isn't great for you", what do you mean exactly?
i'm also looking for specifics like thresholds of acceptable levels of CO2, what levels you want to look out for and why, you see my issue? no one ever gives numbers or explanations, just the vaguest outlines that it's bad. what is it even called when you are experiencing low grade CO2 toxicity?
the medical term for having more CO2 in your blood than normal is hypercapnia. in terms of normal lungs in an atmosphere at normal earth pressure, you start definitely having ill effects at 1% inhaled CO2 by volume (== 10,000 ppm). scientists are starting to find evidence that it starts kicking in somewhere below 1% as well; that said, a lot of the evidence below 1% is still very flaky and incomplete.
Based on working related to facility/building management in the UK, hopefully this is useful:
- Different countries have diff levels they're deciding are thresholds for un/acceptable, but based on what the usual settings on red/amber/green indoor air quality monitors, you want to be opening windows over 800-1,000 CO2 PPM (which most rooms will be with doors closed, ok but a bit unideal). On average, if you've got A/C or a window open your room will hopefully be running at about 600-700. I've seen small meeting rooms with no ventilation get to over 2400 after a few hours, and from that it's a good indication that it's not just CO2 but other VOCs and general germs circulating.
- This article is a digest of this report which assessed 18 studies on IAQ and CO2 levels on health and brain function. It's a bit dense, but key take aways are: - you don't think as well when your brain doesn't have as much fresh oxygen - you perform worse at learning/working, are more lethargic and have increased stress chemicals - spending long periods at much higher levels can negatively impact vascular/brain/other functions, give or take
They've made it a law now in the UK all commercial buildings by next year I think need to have air quality monitors. It's useful as a reference tool, but mostly need to be used as ways to force action in having proper a/c set up - particularly in spaces with large groups, like classrooms (related to that boom in teachers making their own HEPA filters to try and reduce pathogen spread in the early lockdown days).
ohhh this is GREAT! i'm really wanting to buy an at-home CO2 monitor just to check at this point, see what kind of situation i'm rocking
if it's something you're concerned about/interested in, worth investigating! good luck :3