Why ozone hole forms over Antarctica? How will enhanced UV radiations affect us?

Explanation

Ozone is found in stratosphere of atmosphere.
CFC.s (chloroflouro carbons) which are widely used in refrigerators, when discharged from lower atmosphere move upward. In stratosphere UV rays act on these CFC.s and release chlorine atoms. Chlorine degrades ozone and releases molecular oxygen (i.e., `O_3 to O_2`). In this reaction, chlorine acts as catalyst and loss of ozone is irreversible. Thus ozone is depleted. CFCs are having permanent and continuing effect on `O_3` in stratosphere and especially over Antarctica region. This has resulted in the formation of a large area of thinned ozone layer called as ozone hole.
Montreal Protocol has been signed at Montreal in 1987 to control the emission of ozone depleting substances.