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Lok Sabha TV Insights: Rising Ozone pollution in the cities

Lok Sabha TV Insights: Rising Ozone pollution in the cities


Other than ozone in stratosphere, Ozone is also formed at ground level, within troposphere. It is not directly emitted but it is formed due to light and oxides of nitrogen (NOx) and unburned hydrocarbon. This is very important phytotoxic component. Its concentration keep on changing.

Ground-level ozone is formed when nitrogen oxides, carbon monoxide and volatile organic compounds react with sunlight after the chemicals’ released from vehicles, industry, or burning of wood or other plant or animal matter.

In summer, due to high temperature, it concentration increases. This year, it rapidly increased after March and due to heat waves in June, it again rose to very high level. So, prevailing high temperature and its continuous rising will impact the concentration of ozone at ground level in future.

ozone pollution

Ozone is a regional pollutant and not a global pollutant. Since it gets oxidized very easily, so it may disappear after sometime. Ozone has been found even on mountains and is a modern risk.

Globally, USA and other developed countries, even though they have reduced PM pollutant but they are fighting with ozone problem. Ozone does not worsen the situation alone, PM also accompany it. Delhi has become one of the most polluted city in the world and is being compared with Beijing in terms of pollution.

WHO standards are different than Central Pollution Control Board (CPCB) standards. CPCB looks after the pollution control measures in India  


  • Explosive motorization.
  • Use of more number of Diesel vehicles, for which allowed emission limits are more than petrol.
  • Use of more number of private vehicles than the use of public transportation system.


Problem happens when ozone drifts (if it remains static, it may be cleaned) from polluted area to less polluted areas. There it remains for long time, without the presence of NOx.

It impacts the agricultural areas by damaging the crops and in turn it is a threat to food security. Plant suffer due to photosynthetic process, chlorophyll gets attacked and plant is not able to produce shoot and roots. Roots are the most sufferer. For example- wheat, rice, potato. So, it affects the water requirement, production and quality of grains.

Rich and poor are equally vulnerable. Health crisis is increasing due to vulnerability of diseases. It is very harmful particularly for children, since it is formed at ground level and kids due to their height are more vulnerable. Parents are not sending kids to park for playing. It can temporarily affect the lungs, the respiratory tracts, and the eyes.

It is also threat to monuments and overall it causes economic loss to the country in terms of human resource, loss of crops, more expenditure on health security, etc.

Steps required and taken:

  • Regulatory measures are very limited and needs expansion.
  • Sources contributing to ozone pollution needs to be identified and controlled.
  • Steps like “car pool”, using public transport and cycling should be promoted.
  • Central government should define standards for pollutants, power plants, construction activity, industries, etc.
  • Switch from Bharat stage 4 to Bharat stage 6 is needed, with strict implementation.
  • Infrastructure of the cities needs to be changed from car or motor friendly to cycles and other sustainable friendly transportation system.
  • CNG based public transport system is being promoted in populated and polluted cities.
  • Air quality index has been released by India, but is a passive system and not active.
  • Beijing has capped number of car which can be sold in a year.
  • Beijing take pollution emerging action (Red alert system), on days when it is alarming situation, like closing units shutting transportation. It has also banned Diesel car in the cities.