Everything would spontaneously combust, life couldn't exist, and we'd all die very quickly. If the oxygen concentration in the Earth's atmosphere were to increase to 78%, which is significantly higher than the current level of approximately 21%, it would have various implications.
If the percentage of oxygen and nitrogen interchanged, the amount of oxygen become 78%. The probability of fires would greatly increase, resulting in a significant reduction in oxygen and a significant increase in CO2. This leads to difficulty in extinguishing fires. The rate of corrosion of metals will increase.
If our atmosphere was 100% oxygen, plants and cyanobacteria on land and sea would likely not exist as we know them, because they require carbon dioxide to live, with oxygen being a byproduct of their metabolic respiration. Therefore, the insects and animals that depend on them would also likely not exist.
Oxygen enrichment is the generic name for the hazards associated with gases or liquids that contain oxygen concentrations in excess of 21%. As the oxygen in the air increases there is also a significantly increased risk of a fire or explosion.
If we had twice the amount of oxygen we have now, animals would grow larger, Neutrophils would have an increased capacity to fend off harmful viruses and bacteria, and plant life would speed up processes like respiration and combustion.
In just five seconds without the oxygen, the world would look completely different. Without oxygen, our houses, dams, tall building and any structure made out of concrete would collapse instantly. Oxygen is also important for the concrete. It acts as a special binding agent to concrete.
100% Oxygen can be dangerous or even toxic but a relatively modest increase to 30% is unlikely to have many side effects on humans.
At oxygen levels of 10 to 14 percent, faulty judgment, intermittent respiration, and exhaustion can be expected even with minimal exertion (Exs. 25-4 and 150). Breathing air containing 6 to 10 percent oxygen results in nausea, vomiting, lethargic movements, and perhaps unconsciousness.
No, humans cannot live comfortably in a 35% oxygen environment. While the current level of atmospheric oxygen on Earth is around 21%, there have been periods in the past where the oxygen levels were higher, up to 35% or more.
Exposures, from minutes to a few hours, to partial pressures of oxygen above about 1.6 bars (160 kPa)—about eight times normal atmospheric partial pressure—are usually associated with central nervous system oxygen toxicity and are most likely to occur among patients undergoing hyperbaric oxygen therapy and divers.
100% oxygen can be tolerated at sea level for about 24–48 hours without any serious tissue damage. Longer exposures produce definite tissue injury.
Oxygen is not flammable, but it can cause other materials that burn to ignite more easily and to burn far more rapidly. The result is that a fire involving oxygen can appear explosive-like.
In hospital settings, 100% oxygen may be delivered -- but even then only on a short-term basis, says Boyer -- less than 24 hours and preferably less than 12 hours. To breathe pure oxygen at that level for any longer can have toxic results, including "shock lung," or adult respiratory distress syndrome.
Health Line
Anything between 92% and 88%, is still considered safe and average for someone with moderate to severe COPD. Below 88% becomes dangerous, and when it dips to 84% or below, it's time to go to the hospital. Around 80% and lower is dangerous for your vital organs, so you should be treated right away.
Being unreactive, nitrogen does not react with haemoglobin either and therefore it does not participate in respiration at all. All of the nitrogen which is inhaled, is given out during exhalation.
Nitrogen makes up almost four fifths of the air we breathe, but being unreactive is not used in respiration at all - we simply breathe the nitrogen back out again, unchanged. However, nitrogen is essential for the growth of most living things, and is found as a vital ingredient of proteins.
A wet-bulb temperature of 35 °C, or around 95 °F, is pretty much the absolute limit of human tolerance, says Zach Schlader, a physiologist at Indiana University Bloomington. Above that, your body won't be able to lose heat to the environment efficiently enough to maintain its core temperature.
So how did Earth's atmosphere get its oxygen? The simple answer is that early microorganisms produced it using a process you may have learned about in elementary school: photosynthesis. Photosynthesis is the process by which plants and other organisms use sunlight, water, and carbon dioxide to produce energy.
Imagine his shock, then, when he and three colleagues on the top of Mount Everest measured their own blood oxygen level to be between 2.5 and 4 kPa, the lowest ever measured in live people.
Did you know that the maximum amount of air your lungs can hold—your total lung capacity—is about 6 liters?
Oxygen saturation values of 95% to 100% are generally considered normal. Values under 90% could quickly lead to a serious deterioration in status, and values under 70% are life-threatening.
Oxygen is Rare on Mars
There is less than 1% of air on Mars as there is on Earth, and carbon dioxide makes up about 96% of it on Mars. Oxygen is only 0.13%, compared to 21% in Earth's atmosphere. If we want oxygen on Mars, we either have to bring it along, or make it ourselves.
Somewhere between 30,000 and 40,000 feet the pressure around you becomes far too low to push those oxygen molecules across the membranes in your lungs, and you get hypoxic (altitude sickness). If you try to breathe 100 percent oxygen above 40,000 feet for very long without a special type of mask, you'll die.
Once in their suits, astronauts breathe pure oxygen for a few hours. Breathing only oxygen gets rid of all the nitrogen in an astronaut's body. If they didn't get rid of the nitrogen, the astronauts might get gas bubbles in their body when they walked in space.
Changing oxygen level over multiple generations may affect just the maximal size of the largest species, but could also affect the average size of most species.