Could a human live at 150 psi?

[Moontanman]

How much pressure can a human live at without ill effects?

[Acme]

Saturation dives have been done to over 2000 feet underwater where the pressure is over 900psi.

 

Pressure by depth calculator

[MonDie]

Could increasing the air pressure result in oxygen toxicity? I know hypoxia occurs at high altitudes due to lower pressure.

 

At 1 atm (15 psi), the partial pressure of oxygen gas is 0.21 atm (3 psi). Oxygen toxicity occurs at 1.4 atm oxygen gas (21 psi). Tunnel vision, muscle twitching and convulsions.

Edited August 3, 2015 by MonDie

[Acme]

Part of the problem might be breathing. Could increasing the air pressure result in oxygen toxicity?

At 1 atm (15 psi), the partial pressure of oxygen gas is 0.21 atm (3 psi). Oxygen toxicity occurs at 1.4 atm (21 psi) oxygen gas. Tunnel vision, muscle twitching and convulsions.

 

I know people will suffer the opposite problem, hypoxia, when ascending to high latitudes where the air pressure is less.

Saturation diving uses an oxygen/helium mixture to avoid oxygen toxicity as well as nitrogen narcosis. See link above on saturation diving.

 

The extreme opposite would be staying alive in a vacuum which might be possible -according to the following article- for a brief few minutes.

 

Survival in Space Unprotected Is Possible--Briefly

[MonDie]

Then it's answered. Oxygen toxicity will occur at 6.66 atm (98 psi) with normal air.

 

The partial pressure nitrogen gas is 0.78, and nitrogen narcosis occurs at 4 atm nitrogen gas. That comes out to 5.13 atm (75 psi), which is even lower.

[Acme]

Then it's answered. Oxygen toxicity will occur at 6.66 atm (98 psi) with normal air.

 

The partial pressure nitrogen gas is 0.78, and nitrogen narcosis occurs at 4 atm nitrogen gas. That comes out to 5.13 atm (75 psi), which is even lower.

Oxygen toxicity can occur at much lower pressure when diving.

 

What is Oxygen Toxicity?

...CNS [Central Nervous System] oxygen toxicity is usually caused by divers exposing themselves to an oxygen partial pressure of 1.6 ata or greater, and can result in convulsions, pulmonary barotrauma, and death. ...

For diving using regular air the recommended limit for safe recreational diving is 130 ft or 4.93085 ata. This higher pressure than in the previous quote is considered safe when following guidelines for length of time at depth, the pressure being less of course as the diver is ascending or descending.

 

Oxygen Toxicity and Scuba Diving

Scuba divers risk oxygen toxicity if they breathe an excessively high partial pressure (concentration) of oxygen or if they are exposed to elevated partial pressures of oxygen for extended periods of time. Situations in which the risk of oxygen toxicity must[be] managed include diving beyond recreational depth limits on air, diving on enriched air nitrox or another gas mixture with a high percentage of oxygen, and using oxygen or enriched air for decompression stops. ...

The breathing aside and more to Moonntan's point I think, very high pressures do not directly kill humans by damaging tissues. An exception might be in the early days of helmet diving when a diver could be rammed up into his helmet if the air line broke near the surface. In such cases they could be buried in the helmet.

Edited August 3, 2015 by Acme

[Moontanman]

Ok, being a scuba diver myself I should have been more precise, I was thinking of a planetary atmosphere not controlled conditions but you have answered that as well. I was thinking of a planet with a 10 bar atmosphere, I wonder if lower oxygen levels and more neon or helium would help but it would still have to have nitrogen some CO2 at 2 gees helium should be stable in an atmosphere but would hydrogen? That would throw a wrench into the whole idea...

[venus666]

With the development of science, there is possibility live at 150 psi.

[Lagoon Island Pearls]

Increased partial pressure treatment in a hyperbaric chamber is common in medicine for treating many diseases or infections.

 

Oxygen toxicity was mentioned in diving. At 33ft (2atm), pure oxygen is toxic at 2.0pp, but it's often used in decompression stops beginning at 30ft, because most commercial divers are assessed for O2 tolerance during their training. The idea being the sooner you get enriched oxygen into the bloodstream, the quicker nitrogen is purged.

 

Helium is the most common noble in mixed gas operations these days, but it's not so inert as some may think. Helium has a huge affinity for heat, hence divers using it must have an external heat source supplied by the umbilical, namely hot water. Likewise, when any gas is decompressed, it gets colder.

 

Neon and argon have been used in diving too, but breathing concentrations of it cause massive hallucinations. Even hydrogen has been used, but there's no need to explain the danger in that.

 

Most dives are short in duration. Bounce dives can be be mere minutes. Even really deep open circuit dives are under two hours. Mixed gas, four hours, but saturation diving is days, sometimes weeks.

 

Ascending too soon or too fast might seem the same, but are actually two different events.

 

Too soon, short term maladies may be Caisson's disease (bends), skin rashes, exploding dental fillings, which are fluids converting to gas in the bloodstream or joints. Too fast, pneumothorax, mediastinal or subcutaneous emphysema, embolism or sinus/ear reverse block are caused by gas expansion in the lungs or skull.

 

Commercial divers don't have careers expanding across decades, generally.

 

Bad ears and sinuses are often complaints, but osteoarthritis is well documented as one the most common long term effects experienced by deep divers.

 

I'm a diver on my own pearl operation. Commercial decompression diving is not allowed, unless a chamber is immediately available. (which I don't) I get white streaks across my fingernails when I dive for several days in a row, especially on days when I calculate surface intervals between dives, strictly adhering to the tables.

 

Interestingly enough, it's not necessarily pressure itself that causes these issues, but how decompression is managed.

Edited September 18, 2015 by Lagoon Island Pearls