Buzz
Humans survive by inhaling a blend of oxygen and nitrogen. But what effects would pure oxygen have on the body? Viaframe/Getty ImagesIt's common knowledge that oxygen is vital for human survival. However, Earth's atmosphere consists of approximately 78% nitrogen, 21% oxygen, and small amounts of other elements, including water vapor.
Have you ever considered whether inhaling pure oxygen could benefit your health? Surprisingly, it doesn't. In fact, 100% oxygen can be damaging and even poisonous in certain situations. To grasp why, let's delve into the mechanics of how your lungs function.
The structure of your lungs consists of a network of tubes branching from your nose and mouth (starting from the trachea, leading to bronchi, and then to bronchioles), culminating in tiny, delicate air sacs known as alveoli.
Each alveolus is encircled by slender blood vessels called pulmonary capillaries. A thin wall (approximately 0.5 microns thick) separates the capillaries from the alveoli, allowing gases like oxygen, carbon dioxide, and nitrogen to pass through.
During inhalation, the alveoli expand, drawing in oxygen. Due to the higher oxygen concentration in the alveoli compared to the blood in the pulmonary capillaries, oxygen moves from the air into the bloodstream. Similarly, carbon dioxide, being more concentrated in the blood than in the alveolar air, transfers from the blood to the alveoli. Nitrogen levels remain balanced between the blood and alveolar air. This gas exchange depletes oxygen and enriches carbon dioxide in the alveoli, which is then expelled during exhalation.
Just Breathe
What would occur if you inhaled pure oxygen? Certainly nothing beneficial. Inhaling 100% oxygen at standard pressure can result in acute oxygen toxicity, leading to various symptoms, such as:
- Accumulation of fluid in the lungs, difficulty breathing, or rapid breathing
- Chest discomfort, a slight burning sensation when inhaling, and persistent coughing (occasionally with blood)
- Vision issues like blurriness and narrowed field of view
- Headaches, lightheadedness, and confusion
- Collapsed air sacs, known as atelectasis, potentially causing lung swelling
- Elevated body temperature
- Nearsightedness and development of cataracts
Astronauts from the Gemini and Apollo missions, however, inhaled pure oxygen at lower pressures for durations up to two weeks without adverse effects.
There's no need to be concerned about breathing pure oxygen unless in exceptional circumstances. Certain scuba diving equipment, such as F.R.O.G.S. (full range oxygen gas systems), utilizes 100% oxygen for demanding underwater tasks, primarily for military use. Additionally, individuals undergoing hyperbaric oxygen therapy for decompression sickness or severe carbon monoxide poisoning will breathe pure oxygen under close supervision.
Unless you're in one of these specific scenarios, you'll continue breathing the ideal mix of nitrogen and oxygen that supports human life.
