What is ozone hole? Where it is found? What is its effect?

Explanation

Ozone hole is thinning of ozone in the stratosphere where it is normally present in high concentration as ozone layer. Ozone hole is formed during spring time over Antarctica and to a small extent over north pole. Thinning of ozone layer or ozone hole increases the passage of harmful ultraviolet rays to earth.
This has increased incidence of skin cancers, defective eye sight, reduce immunity, increased number of mutations and reduced crop yield.