How does the ozone layer protect us from ultraviolet light?
The ozone layer is located in the stratosphere several miles above the Earth's surface. Ozone is a very important atmospheric gas. As electromagnetic energy travels from the sun through space, it enters the Earth's atmosphere. One of those electromagnetic waves is called ultraviolet light. Ultraviolet light energy gets absorbed by the ozone layer keeping much of those harmful rays away from the organisms on Earth. However, due to the use of chemicals such as chloroflurocarbons or c.f.c.'s in aerosol spray cans and as refrigerants, a hole in the ozone layer formed and was seen back in the 1970's. This is because these chemicals reacted with the ozone and caused a hole to form in the ozone layer. Many countries have stopped using c.f.c.'s and it is estimated that the hole in the ozone layer should eventually close. However, higher levels of ultraviolet light have been linked to skin cancer and the number of cases of skin cancer have been steadily increasing.
Ozone is a molecule made of three oxygen atom or O3. When ultraviolet light in the range 240 and 320 nm strikes an ozone molecule, it absorbs the energy and the O3 changes to O2 and O. The O atom soon combines with another O2 molecule to form O3 and is ready to absorb ultra violet light.
The ozone layer is situated at the highest level of our atmosphere and by absorbing the harmful ultra violet radiation from the Sun, serves a very important purpose. Chlorofluorocarbons or CFCs damage the ozone layer by not allowing O3 to form again once it has split to O and O2 molecules.
Ozone layer protects us from ultraviolet rays by trapping most of the ultraviolet radians in sun rays before it reaches the earth surface. Ozone layer refers to a layer of air in upper atmosphere that contains traces of ozone in it. Presence of ozone prevents most of the ultraviolet radiations present in sun rays from reaching earths surface. This prevents over exposure to ultraviolet rays that can damage plant and create health problems for people.
Pollutants such as CFC rise up in the atmosphere and destroy the ozone present in upper atmosphere. This reduces the thickness of the ozone layer, and along with that its ability to trap ultraviolet rays.