Call Us Now

+91 9606900005 / 04

For Enquiry

Ground-level ozone


According to a new analysis by the Centre for Science and Environment (CSE), parts of the Delhi-NCR region witnessed ground-level ozone exceeding the national standards on 87 out of 92 days between March and May in 2023.


GS III: Environment and Ecology

Dimensions of the Article:

  1. Findings from the report:
  2. Ground-Level Ozone

Findings from the report:

  • Ground-level ozone pollution in Delhi-NCR was lower in 2023 compared to the previous five years, but the duration of its exceedance has increased. This is a cause for concern as elevated ozone levels persist even after sunset, contrary to expectations.
  • Stations reporting exceedance of ozone levels had an average rolling 8-hour average above the standard for 4.9 hours on average this summer, compared to 4.6 hours observed last summer.
  • Ozone pollution is not limited to specific seasons. Even during the winter months when cold and foggy conditions inhibit ground-level ozone formation, Delhi-NCR experienced excess ozone levels on multiple days in January 2023.
  • Ozone levels exceeded the standard at multiple stations for 26 days in January 2023.
  • The areas most affected by ground-level ozone pollution were New Delhi and South Delhi.

Ground-Level Ozone

  • Ground-level ozone, also known as tropospheric ozone, is a colorless and highly irritating gas that forms near the Earth’s surface.
  • It is generated through complex interactions between nitrogen oxides (NOx), volatile organic compounds (VOCs), and carbon monoxide emitted from various sources.
  • Vehicles, power plants, factories, and other combustion sources release these pollutants into the atmosphere.
  • Under sunlight, these compounds undergo cyclic reactions that result in the formation of ground-level ozone.
Impact of Ground-Level Ozone:
  • Ground-level ozone is considered a significant air pollutant.
  • It can have detrimental effects on human health, vegetation, and ecosystems.
  • When nitrogen oxides (NOx) and volatile organic compounds (VOCs) interact in the presence of sunlight, they undergo chemical reactions that lead to the production of ground-level ozone.
  • High levels of ozone can cause respiratory issues, worsen asthma and other respiratory conditions, and contribute to lung diseases in humans.
  • It can also harm crops, forests, and other vegetation, affecting agricultural productivity and ecosystem balance.
Efforts to Address Ground-Level Ozone:
  • Monitoring and controlling ground-level ozone levels are important for mitigating its harmful effects on human and environmental health.
  • Strategies include reducing emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) from sources such as vehicles, industries, and power plants.
  • Implementing air quality regulations, adopting cleaner technologies, and promoting sustainable practices can help minimize the formation and impact of ground-level ozone.

-Source: Down To Earth


February 2024