Delhi smog points to worsening air quality

New Delhi, November 7, 2009: Delhi has finally lost the gains of its CNG programme. Its air is increasingly becoming more polluted and unbreathable, bringing back the pre-CNG days when diesel-driven buses and autos had made it one of the most polluted cities on earth: says the Centre for Science and Environment (CSE) in its latest analysis of recent air quality data in Delhi.

And today’s unprecedented smog is a clear indicator of this, says the CSE analysis.

  • In 2001, when the CNG programme was on, the annual average level of respirable suspended particulate matter (RSPM, or PM10) in residential areas stood at 149 microgram per cubic metre. After registering a drop in 2005, the level has shot up to 209 microgram per cubic metre in 2008. The concentration is, thus, around three times higher than the safe levels.
  • Eight-hourly maximum current level of carbon monoxide (CO) is touching 6,000 microgram per cubic metre – way above the safe level of 2,000 microgram per cubic metre – though the annual levels have registered a drop.
  • Levels of nitrogen dioxide (NO2), though lower than the standard in most areas as yet, have also been increasing marginally (especially at the Town Hall, Chandni Chowk, monitoring point of the CPCB).

“Way back in 2007 we had said Delhi would wake up every winter to more smog and pollution; more wheeze and asthma. Air pollution is on its way back up. It is high time our regulators sat up and set new nation-wide air quality targets,” says Anumita Roychoudhury, head of CSE’s Right to Clean Air campaign.

Pollution control: need to build on past actions

In the past five years, the city has done all it can to reduce pollution. It has advanced emission norms of vehicles; strengthened its ‘pollution under control’ system with new equipment; capped the number of its autorickshaws; converted buses to CNG; made it mandatory for new light commercial vehicles to run on CNG; and restricted commercial vehicles from entering the city.

But in spite of all these actions, pollution levels are on the rise. Delhi has more than four million registered vehicles. Currently, the city adds over 1,000 new personal vehicles each day on its roads. This is almost double what was added in the city in pre-CNG days. And a considerable number of these vehicles run on diesel.

According to the Society for Indian Automobile Manufacturers (SIAM), market share of diesel cars is expected to be 50 per cent of total car sales by 2010. This growth in personal diesel vehicle numbers will undo all the efforts to reduce pollution by phasing out diesel buses and converting them to CNG. According to CSE’s estimates, the total number of diesel cars presently in Delhi is equivalent to adding particulate emissions from nearly 30,000 diesel buses.

Diesel vehicles are known to emit higher smoke, particles and NOx than their petrol counterparts. According to WHO and other international regulatory and scientific agencies, diesel particulates are carcinogens. Even the so-called ‘clean’ diesel running on fuel with 350 ppm of sulphur, allows higher limits for NOx and particulate emissions compared to petrol cars.

The most worrying trend is a decreasing ridership of Delhi’s buses – according to a 2008 study done by RITES, between 2001 to 2007-08, the bus’s share in the modal split has fallen from 60 per cent to 41 per cent.

Delhi’s second generation reforms needed to combat air pollution will need to address these new challenges – the exponential growth of private vehicles and in particular, diesel vehicles in the city, and the need to devote more attention to a viable public transport system.

Official apathy needs to be replaced by proactive steps

It is in this context that the proposed – but not yet notified – new air quality norms acquire significance. Says Roychoudhury: “If the health implications of emerging pollution data were taken seriously, the ministry of environment and forests would have rushed to set new nation-wide air quality targets. After all, the 11th Five Year Plan, already underway, mandates the Central government to set monitorable targets of air quality -- achieve the standards of air quality in all major cities by 2011-12. But somehow the will to tighten the targets has been spirited away.”

The health ministry has warned that India is experiencing a rapid epidemiological transition, with a large and rising burden of chronic diseases, estimated to be more than half of all deaths and 44 per cent of the disability adjusted life years lost. Non-communicable diseases, especially cancer, strokes, and chronic lung diseases are now major public health problems.

Points out Roychoudhury: “The government's inability to prioritize air pollution hazards and its incapacity to act on the health information has slowed down clean technology and sustainable mobility pathways in India. This is clearly not acceptable.”

For more details, please contact

       Anumita Roychoudhury at or Vivek Chattopadhyay at

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