Air pollution in Delhi

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A dense toxic smog in New Delhi blocks out the sun. In November 2017, Delhi's chief minister described the city as a "gas chamber".[1]

The air quality in Delhi, the capital of India, according to a WHO survey of 1600 world cities, is the worst of any major city in the world.[2][3] Air pollution in India is estimated to kill 1.5 million people every year; it is the fifth largest killer in India. India has the world's highest death rate from chronic respiratory diseases and asthma, according to the WHO. In Delhi, poor quality air irreversibly damages the lungs of 2.2 million or 50 percent of all children.

India's Ministry of Earth Sciences published a research paper in October 2018 attributing almost 41% of PM2.5 air pollution in Delhi to vehicular emissions, 21.5% to dust and 18% to industries.[4] The director of Centre for Science and Environment (CSE) alleged that the Society of Indian Automobile Manufacturers (SIAM) is lobbying "against the report" because it is "inconvenient" to the automobile industry.[5]

Air quality index of Delhi is generally Moderate (101-200) level between January to September, and then it drastically deteriorates to Very Poor (301-400), Severe (401-500) or Hazardous (500+) levels in three months between October to December, due to various factors including stubble burning, fire crackers burning during Diwali and cold weather.[6][7][8] In November 2017, in an event known as the Great smog of Delhi, the air pollution spiked far beyond acceptable levels. Levels of PM2.5 and PM 10 particulate matter hit 999 micrograms per cubic meter, while the safe limits for those pollutants are 60 and 100 respectively.[9]

Particulate matter levels in Delhi[edit]

Air quality or ambient/outdoor air pollution is represented by the annual mean concentration of particulate matter PM10 (particles smaller than 10 microns) and PM2.5 (particles smaller than 2.5 microns, about 25 to 100 times thinner than a human hair).[10]

The world's average PM10 levels, for the period 2008 and 2013, based on data of 1600 cities in 91 countries, range from 26 to 208 micrograms per cubic meter of air (μg/m3), with the world average being 71 μg/m3.[2] 13 of the 25 cities worldwide with the highest levels of PM are in India.[11]

In 2010, the year of the WHO survey, the average PM10 level in Delhi was 286 μg/m3. In 2013, the PM2.5 level was 153 μg/m3. These levels are considered very unhealthy. In Gwalior, the city with the worst air quality in India, the PM10 and PM2.5 levels were 329 μg/m3 and 144 μg/m3 respectively. For comparison, the PM10 and PM2.5 levels in London were 22 μg/m3 and 16 μg/m3 respectively. The PM levels in Delhi have become worse since the WHO survey. In December–January 2015, in Delhi, an average PM2.5 level of 226 μg/m3 was noted by US embassy monitors in Delhi. The average in Beijing for the same period was 95.[12] Delhi's air is twice as bad as Beijing's air.[11] As of October 2017, experts in several monitoring stations have reportedly measured an air quality index (AQI) of 999. According to said experts this is the equivalent of smoking 45 to 50 cigarettes a day. This has led to some government officials, such as Arvind Kejriwal calling the nation's capital a "gas chamber".[13]

Safe levels for PM according to the WHO's air quality guidelines are 20 μg/m3 (annual mean) for PM10 and 10 μg/m3 (annual mean) for PM2.5.[14]

Causes of poor air quality[edit]

  • Lack of active monitoring and reaction by authorities.
  • Lack of political priority.
  • Motor vehicle emissions are one of the causes of poor air quality. Other causes include wood-burning fires, fires on agricultural land, exhaust from diesel generators, dust from construction sites, burning garbage [15][16] and illegal industrial activities in Delhi.
  • The Badarpur Thermal Power Station, a coal-fired power plant built in 1973, is another major source of air pollution in Delhi. Despite producing less than 8% of the city's electric power, it produces 80 to 90% of the particulate matter pollution from the electric power sector in Delhi.[17] During the Great smog of Delhi in November 2017, the Badarpur Power Plant was temporarily shut down to alleviate the acute air pollution, but was allowed to restart on 1 February 2018.[18] In view of the detrimental effect to the environment, the power plant has been permanently shut down since 15 October 2018 [19]
  • The drift/mist emissions from the wet cooling towers is also a source of particulate matter as they are widely used in industry and other sectors for dissipating heat in cooling systems.[20]
  • Although Delhi is kerosene free and 90% of the households use LPG for cooking, the remaining 10% uses wood, crop residue, cow dung, and coal for cooking. (Census-India, 2011)
  • Fire in Bhalswa landfill is a major reason for airborne particles in Delhi.[21]
  • Agricultural stubble burning also affects Delhi's air quality when crops are being harvested.[22]

Effects of poor air quality[edit]

Effects on children[edit]

2.2 million children in Delhi have irreversible lung damage due to the poor quality of the air. In addition, research shows that pollution can lower children's immune system and increase the risks of cancer, epilepsy, diabetes and even adult-onset diseases like multiple sclerosis.[23]

Effects on adults[edit]

Poor air quality is a cause of reduced lung capacity, headaches, sore throats, coughs, fatigue, lung cancer, and early death.[14][23]

Smog in Delhi[edit]

Smog in Delhi
Low visibility due to Smog at New Delhi Railway station 31st Dec 2017 after 9AM DSCN8829 1.jpg
Low visibility due to Smog at New Delhi railway station 31 December 2017. Railway building is not visible.
LocationDelhi, India

Smog in Delhi is an ongoing severe air-pollution event in New Delhi and adjoining areas in the National Capital Territory of India.[24] Air pollution in 2017 peaked on both PM 2.5 and PM 10 levels.[25] It has been reported as one of the worst levels of air quality in Delhi since 1999.[26]

Low visibility has resulted in accidents across the city, notably a 24 vehicle pile-up on the Yamuna Expressway.[27]

"The Great Smog" also led to cancellation and delay of public transport, primarily trains and flights, causing much hindrance to the people.[28]


Source of pollution

The current majority of analysis sources are hinting towards colder weather, stagnant winds trapping the various sources of smoke. The primary sources of smoke are stubble burning, lit garbage, road dust, power plants, factories, and vehicles.

Air quality can be measured by the amount of PM 2.5 and PM 10 particulates suspended in air. On 7 November 2017 the PM 2.5 levels in Delhi shot up to an awfully high 999, much above the recommended 60 micrograms. At the same time PM 10 shot to 999 (the maximum level for the monitors), instead of the recommended limit of 100.[9]

Again on 8 November 2017 the PM 2.5 levels shot up to 449. At the same time PM 10 shot to 663.[29]


The temperature in New Delhi during this period was from 15 to 29 degrees C (~66 degrees F).


During the second day of third test of Sri Lankan cricket team in India in 2017-18 at Delhi, smog forced Sri Lanka cricketers to stop play and wear anti-pollution masks. Cricketer Lahiru Gamage reported to have shortness of breath.[30] Nic Pothas, coach of Sri Lankan cricket team, reported that cricketer Suranga Lakmal had vomited regularly due to severe pollution effect on the Delhi ground. There was a haltage of play between 12:32 pm to 12:49 pm which caused Indian coach Ravi Shastri to come out in an aggressive manner and have a talk with the field umpire David Boon.[31]

State reaction[edit]

A Health Emergency was declared in the capital by the Central Government of India in order to cope with the extrusive amount of polluted air. The day was declared as a holiday for schools, offices and other government centers.


Health effects

The government of Delhi has declared a health advisory.[26]

  • Breathlessness
  • Chest constriction
  • Irritation in eyes
  • Asthma
  • Allergy

Control measures[edit]

The Chief Minister of Delhi at that time, Arvind Kejriwal, came out with the following proposed[32] action items to attempt to reduce the air pollution.

  • All Delhi schools will remain shut for the next three days.
  • For the next five days, no construction and demolition work will take place in Delhi.
  • All diesel generator sets have been banned for the next ten days, except at hospitals and in emergencies.
  • The Delhi government will supply power to unauthorized colonies which use diesel generators.
  • The coal-based Badarpur power plant will be shut down for ten days. There will be no fly ash transportation from the power plant.
  • The Environment Department will launch an app to monitor the burning of leaves.
  • Vacuum cleaning of roads will start on 10 November.
  • Water sprinkling will start on all roads from the next following days.
  • People should stay at home as much as they can and they should try working from home.

It has been under public debate how much, if any, of the above steps actually help curtail pollution. Various bodies blamed various sources for the smog.

Longer term measures[edit]

On 25 November 2017, the Supreme Court of India banned the sale of firecrackers in Delhi to alleviate pollution.[33]

In another measure, the Badarpur power plant will remain shut until at least 31 January 2018.[34] This power plant is very old and polluting, and even before the Great Smog, environmentalists had advocated for its permanent shutdown.[35]

Air quality monitoring stations[edit]

The Indian Meteorological Department (IMD) has air quality monitoring stations in Mathura Road, IMD Delhi (Jor Bagh area), IGI Airport, IITM Delhi, Guru Teg Bahadur Hospital (Ghaziabad area), Dhirpur, Delhi Technological University, Pitampura, Aya Nagar (Gurgaon), and Noida.[36] The air pollution monitor of the U.S. Embassy in New Delhi covers the area of Chanakyapuri.[37]

Response of expatriates[edit]

To contend with the poor air quality, embassies and international businesses in Delhi are considering reducing staff tenures, advising staff to reconsider bringing their children to Delhi, providing high-end air purifiers, and installing expensive air purifiers in their offices.[3]

Major incidents[edit]

In December 2017 during a test match between Sri Lankan and Indian cricket teams in New Delhi, Sri Lanka players began to feel breathing problems and several players vomited both in the rest rooms and in the field and had to use face masks until the match was stopped.[38] However Indian side was unsympathetic to the Sri Lankan team, Hindi commentators joked on air that Sri Lankan players were using masks to hide their faces after having taken the beating of their lives while prominent people lauded Indian cricket team's nationalism on Twitter claiming that they sacrificed their health to entertain the crowd that had turned up, while Virender Sehwag called it an act to stop Virat Kohli from scoring a triple century.[39][38] However, after the resumption of the match Indian player Mohommad Shami also vomited. Before Shami had said that while pollution levels are a concern, Indian players are used to such conditions.[40][41] In the opinion of the Indian Medical Association president the match should never have taken place and the ICC should have a policy on pollution.[citation needed]

See also[edit]


  1. ^ "Delhi, Blanketed in Toxic Haze, 'Has Become a Gas Chamber'". New York Times. Archived from the original on 8 November 2017. Retrieved 7 November 2017.
  2. ^ a b "Ambient (outdoor) air pollution in cities database 2014". WHO. 2014. Retrieved 31 May 2015.
  3. ^ a b Harris, Gardiner (14 February 2015). "Delhi Wakes Up to an Air Pollution Problem It Cannot Ignore". New York Times. Retrieved 30 May 2015.
  4. ^ "Usual suspects: Vehicles, industrial emissions behind foul play". Times of India. Retrieved 18 December 2018.
  5. ^ "UA vicious nexus". Down to Earth. Retrieved 18 December 2018.
  6. ^ "Pollution level in Delhi: Day after Diwali, Delhi's air turns 'hazardous".
  7. ^ "Delhi breathed easier from January to April".
  8. ^ "Air pollution: Delhi enjoys cleanest February in three years".
  9. ^ a b Express Web Desk (1 November 2016). "Diwali effect: Pollution worsens, particulate matter soars in Delhi". Indian Express.
  10. ^ "Ambient (outdoor) air pollution database, by country and city". WHO. Retrieved 31 May 2015.
  11. ^ a b Alissa Walker, Alissa (29 May 2015). "India's Air Pollution Is So Bad It's Causing Lung Damage in Kids". gizmodo. Retrieved 30 May 2015.
  12. ^ Air Pollution in India: Real-time Air Quality Index Visual Map,
  13. ^ Roli Mahajan (15 March 2018). "10% of the disease burden". D+C, development and cooperation. Retrieved 7 May 2018.
  14. ^ a b "WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide Global update 2005 Summary of risk assessment" (PDF). WHO. 2005. Retrieved 31 May 2015.
  15. ^ Bengali, Shashank. "To fight the world's worst air pollution, New Delhi forces cars off the roads". LA Times. pp. 4 January 2016. Retrieved 7 December 2017.
  16. ^ HT Correspondent (4 January 2016). "A history of Delhi's air pollution: Can road rationing even the odds?". Hindustan Times. Retrieved 7 December 2017.
  17. ^ "The Badarpur Plant's effect on Air Pollution and why it needs to be shut down". The Economic Times. 12 August 2016. Retrieved 25 November 2016.
  18. ^ "Badarpur thermal power plant to remain shut till Jan 31 2018". Indian Express. 17 November 2016. Retrieved 25 November 2016.
  19. ^ "Badarpur thermal plant, Delhi's biggest power generator, to shut down from October 15".
  20. ^ "Wet cooling towers: guide to reporting". Retrieved 19 October 2018.
  21. ^ "Bhalswa landfill site major factor of air pollution: Jain". Business Standard India. Press Trust of India. 5 November 2016. Retrieved 7 December 2017.
  22. ^ "Stubble burning begins: Hold your breath Delhiites, that deadly smog is coming". 9 October 2017.
  23. ^ a b HARRIS, GARDINER (29 May 2015). "Holding Your Breath in India". SundayReview, New York Times. Retrieved 30 May 2015.
  24. ^ Sweta Goswami (7 November 2017). "Delhi's worst smog yet wakes up govt, emergency measures announced". Hindustan Times.
  25. ^ Express Web Desk (2 November 2017). "Delhi wakes up to hazardous pollution levels, reduced visibility due to smog". Indian Express.
  26. ^ a b PTI (8 November 2017). "Delhi pollution: Government issues health advisory as smog chokes city". Hindustan Times.
  27. ^ "Blinding Smog Causes 24-Vehicle Pile-Up On Expressway Near Delhi". Retrieved 9 November 2017.
  28. ^ "Delhi wakes up to dense smog; train services suspended due to low visibility". Times Now Bureau. 6 November 2017. Retrieved 9 November 2017.
  29. ^ "Delhi Smog and band aid efforts to patch it". 8 November 2017.
  30. ^ "Pollution stops play at Delhi test match as bowlers struggle to breathe".
  31. ^
  32. ^ TNN (6 November 2016). "Air pollution: Delhi shuts schools, bans construction work". Times Of India.
  33. ^ "Supreme Court bans sale of firecrackers in Delhi, NCR". Times of India. Retrieved 25 November 2016.
  34. ^ "Badarpur thermal power plant to remain shut till Jan 31, 2017". Indian Express. 17 November 2016. Retrieved 25 November 2016.
  35. ^ "The Badarpur Plant's Effect on Air Pollution and Why It Needs to Be Shut Down". The Economic Times. 12 August 2016. Retrieved 25 November 2016.
  36. ^ "Monitoring Stations". System of Air Quality Weather Forecasting and Research, Indian Institute of Tropical Meteorology, Pune. Ministry of Earth Sciences, Govt.of India. 2015. Retrieved 2 June 2015.
  37. ^ US Embassy (30 May 2015). "Air Quality Data". New Delhi, India: usembassy. Archived from the original on 11 June 2015. Retrieved 30 May 2015.
  38. ^ a b Safi, Michael (3 December 2017). "Pollution stops play at Delhi Test match as bowlers struggle to breathe". The Guardian. ISSN 0261-3077. Retrieved 5 December 2017.
  39. ^ "Sehwag slams SL players for complaining about smog". Daily Mirror - Sri Lanka. Retrieved 5 December 2017.
  40. ^ "Mohammed Shami vomiting, tests in Sri Lanka camp add to pollution debate in Delhi". Hindustan Times. 5 December 2017. Retrieved 5 December 2017.
  41. ^ "India vs Sri Lanka: Mohammed Shami pukes at Feroz Shah Kotla". The Indian Express. 5 December 2017. Retrieved 5 December 2017.

Further reading[edit]

  • Cherni, Judith A. Economic Growth versus the Environment: The Politics of Wealth, Health and Air Pollution (2002) online
  • Currie, Donya. "WHO: Air Pollution a Continuing Health Threat in World's Cities," The Nation's Health (February 2012) 42#1 online
  • Amann, M., Purohit, P., Bertok, I., Bhanarkar, A.D., Borken‐Kleefeld, J., Cofala, J., Harshvardhan, B., Heyes, C., Kiesewetter, G., Klimont, Z., Jun, L., Majumdar, D., Ngyuen, B., Rafaj, P., Rao., P.S., Sander, R., Schöpp, W., Shrivastava, A. 2017. Managing future air quality in megacities: A case study for Delhi. Atmospheric Environment, 161: 99–111. [1]
  • Bhanarkar, A.D., Purohit, P., Rafaj, P., Amann, M. et al. 2018. Managing future air quality in megacities: Co-benefit assessment for Delhi, Atmospheric Environment, doi:

External links[edit]