Whats the easiest way for a brainlet to calculate the breathability of an atmosphere if given:
1. Atmospheric pressure
2. % of O2 in Atmosphere
Whats the easiest way for a brainlet to calculate the breathability of an atmosphere if given:
Xavier Jackson
Jaxon Long
Breath-ability isn't just about O2 content. Even if you have ideal O2 levels, you're going to have trouble breathing if the rest of it is nerve toxin or scalding hot steam
Nathan Bailey
understood but if no toxins exist at enough concentration to harm.....
like say an atmospheric mixed of just N2 and O2....
how do I find the threshold of hypoxia or hyperoxia?
also does air pressure effect the toxicity of CO2?
Jason James
The percentage of o2 in air is always 21, what changes is the amount of molecules of air on a same volume at different pressures.
>P1V1 = P2V2
So you need to research what's the least volume of oxygen that's livable, then plug that in and solve.
Nolan Barnes
hyperoxia is tricky, because people can easily live in a 100% oxygen atmosphere
Now hypoxia, you'll have to do your research. The actual equations are pretty easy.
Parker Diaz
>The percentage of O2 in air is always 21
only on Earth
how do I figure for different ratios of oxygen to atmosphere?
Dylan Kelly
>people can easily live in a 100% oxygen atmosphere
no side effects for long-term habitability?
Gabriel Davis
Read about arterial oxygen partial pressure, that's the limiting factor you're actually looking for.
Yes, I think there are side effects after 24 or 48 hours can't remember, but if the therapeutic use is needed, they may keep a patient on 100% o2 for more than that.
Asher Hall
thanks for the lead
gonna look some stuff up
Ryan Hughes
OSHA says anything between 19.5-23.5% is good.
The absolute minimum to not asphyxiate is 6%.
I'd assume hyperoxia is dependent on other factors like pressure and solubility so it's much more complicated. 1atm of 100% oxygen gas won't hurt you.
Hudson Mitchell
Also blood gas tension stops being a brainlet problem after you start taking other gases and different gas concentrations on the atmosphere into account. It may take a few hours or even days until you have a generalized system.
Jacob Adams
i think I'm on to something
>Calculating the Alveolar PO2
Gabriel Murphy
>The absolute minimum to not asphyxiate is 6%
Wouldn't this depend on partial pressure more than absolute percentage, or is there are reason it would be impossible to survive in 1% oxygen at 20+ atmospheres?
Josiah Torres
I think he means at 1 atm
Isaiah Reed
Also at such a high pressure you have other problems like N becoming toxic, this is why I said it's a pretty difficult question. Or at least a complex one if not difficult.
Tyler Wood
OP here
im trying to determine breathability based on variable
1. air pressure
2. % of O2
im not sure im calculating PAO2 correctly
say i wanted to determine my ability to breath in 3.56 atm of pressure with a composition of 27.3% O2.
how would that look?
Ayden Reed
also water vapor is
0.00138 atm
Easton Baker
20atm would cause so many other problems that oxygen content wouldn't matter.
Yes, it's partial pressures. I thought I wrote that but evidently I didn't. A simple way to determine "could I breathe this and not die?" is comparing partial pressures. You need ~.195atm oxygen partial pressure to live. If you know the oxygen content of the atmosphere and the pressure then just determine the partial pressure and compare. If it's less than ~.195atm it's going to cause problems.
Ex you have an atmosphere of 3.762atm with 39% oxygen 61% nitrogen. Partial pressure of oxygen is 1.46atm so you won't asphyxiate.
Ex2 atmosphere 0.56atm oxygen content 16% partial pressure 0.09atm no you die.
Zachary Clark
makes sense.
wouldn't the volume of CO2 and H20 also play a part in hypoxemia?
as in the Aveolar Gas Equation?
Easton Murphy
yeah but you asked in the OP for the easiest way. if you don't have enough water vapor in the air you'll destroy your lungs anyway but that's not "the easiest way."
if you're going to use that equation you'd also need to consider the rest of the atmosphere and how it interacts with the atmospheric pressure and a bunch of other complicated shit. your earlier example of 20atm 1% oxygen is "breathable" with a partial pressure of .2atm but you'll be dissolving lots of nitrogen into your blood and die anyway.
Gabriel Martinez
might not be breathable actually
dunno if that much nitrogen would just act like an atmospheric exit bag even if you have oxygen available
Blake Miller
got it.
Henry Anderson
>20atm would cause so many other problems that oxygen content wouldn't matter.
Technically, it's still survivable. The record for the deepest SCUBA dive is 332.35 meters, which would have a pressure of greater than 30 atmospheres.
en.wikipedia.org
Really, diving info seems to be the best source for information about gas breathablity.
>dunno if that much nitrogen would just act like an atmospheric exit bag even if you have oxygen available
It would: en.wikipedia.org
At those pressures people use helium-nitrogen-oxygen mixtures.