Explain Ozone Depletion in the Stratosphere.

(N/A) Ozone found in the upper part of the atmosphere,called the stratosphere,acts as a shield by absorbing ultraviolet $(UV)$ radiation from the sun.
$UV$ rays are highly injurious to living organisms.
The thickness of the ozone layer in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson units $(DU)$.
Ozone layer absorbs the harmful $UV$-rays.
$UV$ radiation causes aging of the skin,damage to skin cells,and various types of skin cancers.
In the human eye,the cornea absorbs $UV-B$ radiation,and a high dose of $UV-B$ causes inflammation of the cornea,called snow-blindness,cataract,etc.
Such exposure may permanently damage the cornea.
Chlorofluorocarbons $(CFCs)$ deplete the ozone layer.
The part of the atmosphere with a lesser concentration of ozone is called an ozone hole.
Steps leading to ozone depletion:
$1$. $UV$-rays split $CFCs$ and release atomic chlorine $(Cl)$.
$2$. $UV$-rays also split ozone into oxygen.
$3$. Chlorine atoms trap oxygen atoms,and ozone is not formed again from oxygen.
This leads to the depletion of ozone in the stratosphere.