Ozone is a form of oxygen having the molecular
form of O3. It
is a bluish, unstable gas with a pungent odour, found
in two parts of the atmosphere: the stratosphere
and the troposphere.
The ozone layer:
The stratosphere contains a layer in which the
concentration of ozone is greatest, the so called
ozone layer. The layer extends from about 12 to
40 km. It shields the Earth from ultraviolet radiation's
harmful health effects on humans and the environment.
This layer is being depleted by human emissions
of chlorine and bromine compounds.
At ground level (in the troposphere), ozone is
considered an air pollutant that can seriously
affect the human respiratory system. It is a chemical
oxidant and a major component of photochemical