Oxygen is one of the most important and abundant elements on Earth

Oxygen is one of the most important and abundant elements on Earth. About 46 percent of the Earth's crust is oxygen. It is colorless and odorless and makes up about 20.95 percent of the atmosphere by volume. Oxygen exists in water as part of water molecule, in the atmosphere as a gas, in the Earth's crust and in an enormous variety of rocks and minerals. It can also be released from the plants through photosynthesis. Moreover it …

…nitrogen dioxide from cars. In contrast, the "good ozone" exists in the upper layers of the Earth's atmosphere. It shields the surface of the Earth from UV radiation emitted by the sun. As a result, Oxygen is indeed an important key to good health. Torn Valentine, author of "Medicine's Missing Link", says, "It would be interesting to compare the amount of Oxygen in a strong, healthy person with the amount in a chronically ill individual."