It is necessary to control pollution at a right time and to the right extent.

Explanation

The increasing amount of solid waste, sewage and various pollutants has resulted in increasing pollution.
ii. Increase in pollution cause degradation of the environment as well as affects the health of humans.
iii. Such problems are commonly found i densely populated countries like India.
iv. If these problems are not solved at a right time and to the right extent, the life of future generations will be difficult.