UPSC Mains 2019: Delhi Air Pollution

delhi air pollution


Topic: Private Cars in Delhi Will Be Pulled Off From Roads If Air Quality Worsens

Topic in Syllabus: GS Paper 3: Ecology and Environment

delhi air pollution



Environment Pollution Control Authority has said that private cars will be stopped from running on the roads in the national capital if air pollution worsens.



  • India has the world’s highest rate of death from respiratory disease, according to the World Health Organisation, with 159 deaths per 100,000 people in 2012, about five times that of the UK and twice that of China.
  • Air quality in the Indian capital is one of the world’s most polluted cities. A 2015 study found about half of Delhi’s 4.4 million schoolchildren had compromised lung capacity and would never completely recover.
  • Bad air has also become a permanent winter fixture in Delhi. Last year, the National Air Quality Index ranked the city’s air as “severe” on 20 days in November. Immediately after it was ranked poorly by the air quality index, Delhi received another admonition with the Supreme Court describing the city as a “gas chamber”.
  • The rebuke led the Delhi government to ration road space in January and April. For 15 days in these two months, cars and two-wheelers with odd/even numbers ran on alternate days.


Air Pollution:

  • The pollution of air goes unnoticed most of the time. All human activity from domestic cooking to highly mechanised industries contribute to air pollution.
  • In India alone, stupendous amounts of air pollutants enter the atmosphere per annum. The pollutants comprise of 50 lakh tonnes of particulate matter, 30 lakh tonnes of sulphur dioxide, 10 lakh tonnes of carbon monoxide and 22 lakh tonnes of hydrogen sulphide.
  • Clean air, which is essential for the survival of all living organisms, is rapidly becoming scarce. At mean sea levels air contains 20.94% oxygen and 78.09% nitrogen. Other elements present comprise less than one percent of its composition.
  • Air pollution can be due to natural or man-made causes. The former is beyond our control as natural disasters like dust storms, earthquakes and volcanic eruptions throw up large quantities of dust and gases into the atmosphere. Man-made causes, however, should be prevented or controlled as they pose a greater danger by way of toxic emissions from factories, power plants, vehicular traffic, etc. Industries such as mining, thermal plants, brick kilns, etc. also pollute the air. These emissions are particularly intense in urban conglomerations where the density of human habitation is very high.


Types of Air pollutants

  • Primary pollutants are those which are emitted directly into the atmosphere, like sulphur dioxide, nitric oxides and carbon monoxide.
  • Secondary pollutants are pollutants formed by the photochemical reaction of primary pollutants. For example, “smog”, is a combination of smoke and fog. Smoke consists of carbon particles and fog is an emulsion of water vapour in air. Smog has become very common in large cities, especially during winter. Similarly acid rain is formed by the combination of sulphur dioxide and water vapour present in the air.


Sources of Delhi Air Pollution:

Air pollution in Delhi’s National Capital Region (NCR) is comprised of a complex mix of pollution from human activities (vehicle emissions, industry, construction and residential fuel burning) as well as natural sources like dust and sea salt. The heavy concentration of particulate matter is greatly affected by meteorological conditions –in the winter, cool air causes “inversions” that stagnant the air and trap pollution close to the ground

  • Vehicles:These are the second largest source of particulate matter, particularly PM2.5. According to the report, vehicular pollution grew from 64 per cent to 72 per cent between 1990 and 2000. In winter, on average vehicles can contribute 25 per cent to PM2.5 and at certain locations this could be above 35 per cent. There is a significant contribution of diesel vehicles to PM10 and
  • Road dust:The silt load on some of Delhi’s roads is very high and silt can become airborne with the movement of vehicles. The estimated PM10 emission from road dust is over 65 tonnes per day. Soil from open fields too gets airborne in summer. In some parts of the city, roads are broken, poorly maintained and partially paved surfaces and the study found that movement of vehicles may cause non-exhaust road dust emission in significant amounts. PM10 and PM2.5 emission from road dust is 79,626 kg/day and 22,165 kg/day respectively.
  • Concrete batching:During the study period massive construction activities were found that required concrete batching, including at 60 DMRC locations where construction was under progress. It was assumed that there will be 40 concrete batching plants of 120 cu.m/hr capacities operating for 16 hours. Several medium and small construction activities were also observed in the city. PM10 and PM2.5 emissions from concrete mix plants is estimated at 14.37 tonnes/day and 3.5 tonnes/day respectively. A few hundred plants in NCR may contribute to this.
  • Hotels and Restaurants:The average consumption of coal in tandoors based on the survey was 30 kg/day. The number of hotels and restaurants was 36,099 (Delhi Statistical Handbook, 2014). The study assumes 25% of these enterprises use tandoors for food preparation.
  • Municipal solid waste burning:The contribution of burning MSW may surprise many. A study in 2015 in Delhi has estimated 190 to 246 tonnes/day of MSW burning.
  • Stubble burning in neighboring states:NASA image suggests that burning of crop stubble is considerably impacting the pollution levels. Farmers in neighbouring Punjab and Haryana have been setting fire to paddy stubble in their fields after cultivating the crop as part of the slash and burn. As per an NYT report, farmers are burning around 32 million tons of leftover straw.
  • Meteorological:During the winter months, cool air stagnates over the city, keeping pollution close to the ground where people breathe. Delhi’s persistent winter fog only worsens the problem. Stagnant air explains why pollution levels vary less widely over the day in winter than in spring, as is evident in the chart above. In spring, warm, rising air moves pollution out, so the average pollution at ground level follows more closely the profile of polluting activities throughout the day. During the afternoon when people are at work, it drops, only to rise again with the evening rush hour. It stays relatively high overnight, likely due to the practice of trucking goods, not only in and out but through Delhi.


How prepared is Delhi to face the smoggy situation this year?

  • With the 2017 ban of petroleum coke, a dirtier alternative to coal, and the closure of the Badarpur Thermal Power Plant scheduled for October, Delhi could witness better air quality this year,
  • Delhi has already seen better air quality days this year than it has since 2016, claimed a study, in August that between January 1 and August 26, the Central Pollution Control Board, had recorded 118 days in Delhi when the Air Quality Index was moderate to satisfactory. This is five more than 113 days of good to moderate air quality in 2017 and 74 days in 2016.
  • The report added that pollution control board officials said that the city’s air quality had improved after measures such as the Graded Response Action Plan and the Comprehensive Action Plan were implemented. The Graded Response Action Plan was put in place in 2017 on the directions of the Supreme Court. Under it, different government agencies are required to draw up a step-by-step action plan to control air pollution at an early stage.
  • Construction would be halted, diesel generators will be shut and vehicular movement would be restricted. The Comprehensive Action Plan was finalised by the Union environment ministry in March specifically to manage air pollution in the Delhi-National Capital Region.
  • Delhi’s transport commissioner Varsha Joshi said that the government was better equipped to handle the situation this year as it has taken measures to scrap old vehicles and increase last-mile connectivity in the transport sector. “The last lot of the old yellow and green Delhi Transport Corporation buses have been removed,”
  • In August, the Central Pollution Control Board started introducing dust suppressing and other air purifying machines in parts of the city to curb air pollution and trap particulate matter.


What needs to be done to improve the air quality in Delhi?

  • A robust public transport system is one of the bare essentials. Several studies have shown that public transport provides more than 65% of Delhi’s commuting needs but occupies less than five per cent of road space.
  • Public transport in itself, however, might not be enough. Economists believe that the middle classes are likely to remain enamoured with cars unless there are strong disincentives to using personal transport. They advocate a combination of pollution taxes, car free days/areas, robust public transport and better urban planning.
  • Congestion tax can also be considered. London, Milan, Oslo, Stockholm and Singapore have introduced congestion taxes to curb cars.
  • An odd-even trial in the summer months might be more useful to isolate its impact.
  • The government’s proposal to vacuum-clean roads in April is promising, given that the IIT Kanpur study attributed 38% of pollution to road dust.
  • The government could also resort on other measures including temporary controls on industry and construction, and banning the use of fireworks.
  • In the long run, an essential step would be to draft a new transportation policy, without emphasising only economic aspects as was done earlier.
  • Consulting urban planners, logisticians, sociologists, environmentalists, civil society groups including doctors, teachers and lawyers, the police and the military, apart from economists would be essential.
  • CSIR’s proposal- mid-week work-from-home– can be a game changer too. According to this formula, instead of commuting to work and school, employees and students could work and study from home for a day.
  • Delhi government implemented the Odd-even formula in the National Capital Region on a trial basis. But, there has not been any credible data to support the Delhi government’s claim that the odd-even trial has reduced pollution or improved air quality.


Government should do:

  • The government, in partnership with non-governmental organizations, technical specialists and research organizations, needs to initiate a clean air campaign. This needs to take the form of legislation as well as behavior-changing approaches.
  • Governments, both at the Central and state level, need to reassess their production and consumption of energy and work with partners for a low-carbon future — one that is more efficient, has more natural gas and a growing share of renewable energy, such as solar and bio-gas.
  • Public policy must address the various factors that contribute to toxic air, without damaging the core activities that are crucial to economic growth, which requires coordination across sectors, from industry and power to transport and cooking.
  • Governments at the Centre and local levels must also demonstrate the political will to tackle what is a catastrophic public health problem. Local governments must clamp down on the specific pollutants that are pushing their respective cities into the danger zone.


Sample Question:

Q) Critically examine the root causes of air pollution in Delhi and reasons why various initiatives have failed to have any impact on its reduction. (250 Words)