Question

$O_3$ is a pollutant gas in

• A. Tropopause
• B. Lower stratosphere
• C. Troposphere
• D. Mesosphere

Answer 1

Answer: (C)

Troposphere

Ozone layer or shield is present in the stratosphere. It is also called as ozonosphere. Ozonosphere lies at altitude of 23 to 25 km over equator and at slightly lower altitude elsewhere. Ninety percent of atmospheric ozone is present in the ozonosphere. Ozone present in troposphere is a pollutant and extremely harmful. It is called as 'Bad Ozone'. Ozone found in stratosphere is useful for life on earth as it protects the earth from harmful ultra-violet rays and other radiations. It is therefore called as 'Good Ozone'.