(N/A) The ozone hole is most prominent over the Antarctica region. It is formed due to the increased concentration of chlorine in the atmosphere.
Chlorine is primarily released from chlorofluorocarbons $(CFCs)$ which are widely used as refrigerants. These $CFCs$ migrate from the troposphere to the stratosphere,where they release chlorine atoms through the action of $UV$ rays. The released chlorine atoms catalyze the conversion of ozone $(O_3)$ into molecular oxygen $(O_2)$. $A$ single atom of chlorine can destroy approximately $10,000$ molecules of ozone,leading to significant ozone depletion.
The formation of the ozone hole results in an increased intensity of $UV-B$ radiation reaching the Earth's surface. $UV-B$ radiation damages $DNA$ and accelerates skin ageing. It also causes skin darkening and increases the risk of skin cancer. Furthermore,high levels of $UV-B$ exposure can cause corneal cataracts in human beings.