Ozone Pollution

Ozone Pollution : A recent analysis by the Centre for Science and Environment (CSE) has revealed dangerously high levels of ground-level ozone pollution across Delhi-NCR during the summer of 2025.

• Key Findings : Ground-level ozone exceeded national safety limits on nearly all summer days across Delhi-NCR.

o Ozone Surpasses PM2.5: Ozone became the lead pollutant in Delhi’s AQI for an extended period, overtaking fine particulate matter.

o Persistent Night-Time Pollution: Ozone levels stayed high into the night, averaging 14–15 hours of exceedance daily. Gwal Pahari (Gurugram) had the most night-time spikes.

o Health & Agricultural Risks: Ozone exposure can trigger respiratory issues and worsen lung diseases. Ozone drifts into rural areas, potentially harming crop yields and food security.

• About Ozone : A gas made up of three oxygen atoms (O₃) and it exists both in the upper atmosphere and at ground level.

o Good Ozone (Stratospheric Ozone): Located in the stratosphere (6 to 30 miles above Earth).

ü Forms the ozone layer, which protects life by blocking harmful ultraviolet (UV) rays from the sun.

o Bad Ozone (Ground-Level Ozone): Found in the troposphere (Earth’s surface up to ~6 miles high).

ü Formed by chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in sunlight.

ü A key component of urban smog.

ü Harmful to human health (causes respiratory issues) and damaging to crops, forests, and other vegetation.