In news:  

  • Delhi recorded an ozone pollution which is 1.22 times higher than the eight-hour average standard for ozone exposure that is 100 ug/cu m. 
  • According to an analysis by Centre for Science and Environment (CSE), people in Delhi faced more days with average ozone levels spiking over the national air quality limits in 2019 than 2018.


Ozone pollution: It is a secondary pollutant


  • Ozone is not directly emitted from any source. It gets formed when emissions from vehicles, industry or power plants — nitrogen oxide and volatile organic compounds — react in the air under the influence of sunlight and temperature. 
  • It is also the third most important greenhouse gas after carbon dioxide and methane.

Ozone: Ozone or trioxygen, is an inorganic molecule.

  • Ozone (O3) is a highly reactive gas composed of three oxygen atoms. 
  • It is both a natural and a man-made product that occurs in the Earth's upper atmosphere (the stratosphere) and lower atmosphere (the troposphere).  Depending on where it is in the atmosphere, ozone affects life on Earth in either good or bad ways.


ozone molecule

Impact of ozone pollution: 

Environmental impacts: Ozone affects sensitive vegetation and ecosystems, including forests, parks, wildlife refuges and wilderness areas.  In particular, ozone harms sensitive vegetation during the growing season. 

Health Impacts: Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and airway inflammation. It also can reduce lung function and harm lung tissue. Ozone can worsen bronchitis, emphysema, and asthma, leading to increased medical care

Global efforts to combat Ozone Pollution: 

  • Gothenburg Protocol: The 1999 Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone (known as the Multi-effect Protocol or the Gothenburg Protocol) is a multi-pollutant protocol designed to reduce acidification, eutrophication and ground-level ozone by setting emissions ceilings for sulphur dioxide, nitrogen oxides, volatile organic compounds and ammonia to be met by 2010. As of August 2014, the Protocol had been ratified by 26 parties, which includes 25 states and the European Union.
  • National Air Quality Index (AQI) transforms complex air quality data of eight pollutants into a single number (index value), nomenclature and colour.National Air Quality Index (AQI) was launched on 17 October 2014 to disseminate information on air quality in an easily understandable form for the general public. The measurement of air quality is based on eight pollutants(up to 24-hourly averaging period) , namely,
  • Particulate Matter (size less than 10 µm) or (PM10),  
  • Particulate Matter (size less than 2.5 µm) or (PM2.5),
  • Nitrogen Dioxide (NO2),
  • Sulphur Dioxide (SO2),
  • Carbon Monoxide (CO),
  • Ozone (O3),
  • Ammonia (NH3), and
  • Lead (Pb)
  • SAFAR: SAFAR envisages a research based management system where strategies of air pollution mitigation go hand in hand with nation’s economic development to target a win-win scenario.
  • Ministry of Earth Sciences (MoES), Govt. of India, has introduced a major national initiative, "System of Air Quality and Weather Forecasting and Research" known as "SAFAR" for greater metropolitan cities of India to provide location specific information on air quality in near real time and its forecast 1-3 days in advance for the first time in India. 
  • It has been combined with the early warning system on weather parameters.
  • The SAFAR system is developed by Indian Institute of Tropical Meteorology, Pune, along with ESSO partner institutions namely India Meteorological Department (IMD) and National Centre for Medium Range Weather Forecasting (NCMRWF). 
  • The implementation of SAFAR is made possible with an active collaboration with local municipal corporations and various local educational institutions and governmental agencies in that Metro city. 
  • The ultimate objective of the project is to increase awareness among the general public regarding the air quality in their city well in advance so that appropriate mitigation measures and systematic action can be taken up for betterment of air quality and related health issues.