It was not so long ago that breathing enough Oxygen was an issue that needed discussion. But increased combustion, pollution, deforestation, and man-made processes, have reduced oxygen levels in to less than 21%. And in the urban areas, the percentage is even lesser - 12%. This problem is not limited to outdoors but indoor air is also affected.
 What is Oxygen?
Oxygen is a colorless, odorless, tasteless gas. Oxygen is extremely active chemically, forming compounds with almost all of the elements except the inert gases. Oxygen unites directly with a number of other elements to form oxides. It is a constituent of many acids and of hydroxides, carbohydrates, proteins, fats and oils, alcohols, cellulose, and numerous other compounds such as the carbonates, chlorates, nitrates and nitrites, phosphates and phosphites, and sulphates and sulphites.
The common reaction in which it unites with another substance is called oxidation (see oxidation and reduction). The burning of substances in air is rapid oxidation or combustion. The respiration of animals and plants is a form of oxidation essential to the liberation of the energy stored in such food materials as carbohydrates and fats. The rusting of iron and the corrosion of many metals results from the action of the oxygen in the air.
 Did you know?
- The American Medical Association says that 94% of all respiratory illnesses are caused by polluted air or a lack of oxygen. It also reported that 1/3 of our US national health bill is for causes directly attributable to indoor air pollution.
- According to experts the Oxygen levels of our atmosphere have dropped by as much as 50% over the past 500 years.
- We yawn because oxygen levels in our lungs are low. Yawning heightens alertness as the sudden intake of oxygen increases the heart rate, rids the lungs and the bloodstream of the carbon dioxide build-up, and forces oxygen through blood vessels in the brain, while restoring normal breathing and ventilating the lungs.
- Bulk of atmosphere is made of nitrogen (77%) followed by oxygen (21%).
- At 7% level of Oxygen in the atmosphere human life can no longer exist.
- Antoine Lavoisier is credited with discovering that the air is made of oxygen
and nitrogen in the late 1700s.the bitch said
- Fish get their oxygen from the water not air.
- Are we getting enough Oxygen?
- pure O2.
- Cool facts