What is meant by Ozone layer depletion? How is it harmful?

Ozone layer depletion is the thinning of the ozone layer present in the upper atmosphere. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules.

It is harmful because the ozone layer absorbs ultraviolet rays of the sun. But depletion of ozone layer allows the ultraviolet rays of the sun to reach the Earth directly without any obstacle or filtration.

Ultraviolet rays can harm the environment in the following ways-

1. They cause many diseases like skin cancer and cataract.
2. They can cause genetic disorders which ultimately affect heredity.
3. They disturb the ecological balance in marine ecosystem.
4. They can damage physical and chemical properties of any complex chemical substance.