India to finally get a national air quality index

Proposed air quality index is an important step forward to achieve clean air standards and reduce public health risk, says CSE

Published: Friday 17 October 2014

India now joins the global league of countries like the US, China, Mexico, France and Hong that have implemented smog alert systems (Photo courtesy :

After a long wait, the Union ministry of environment and forests (MoEF) has finally released the first ever draft proposal on air quality index (AQI) and health alert for public comments. It was released by Union minister of state for environment, Prakash Javadekar, on Friday.  
The Centre for Science and Environment (CSE), a Delhi non-profit that has been continuously campaigning for clean air rights of people, has welcomed the draft proposal. 

CSE has also applauded the ministry’s new initiative of introducing a health advisory to inform people about the degree of severity of daily air quality and the health consequences. This can help people take precautions on days when the air quality is poor. Javadekar, while releasing the air quality index, said: “Now one number, one colour and one description will help people to understand the quality of air they are breathing.”

Said Anumita Roychowdhury, CSE’s executive director-research and advocacy and head of its air pollution team: “CSE has been demanding adoption of this programme as this can help people to understand the quality of air and the possible health effects. This is needed to demystify complex air quality data, help promote public awareness and build public pressure for effective air pollution control in cities.” 

AQI is a method by which daily air quality is classified according to actual concentration of pollutants and described simply for informing people.

The index was prepared by an expert group set up by MoEF that included prominent medical doctors from leading hospitals, research bodies including IIT Kanpur, and CSE.

Key highlights of the proposed index:

  • Pollutants to be monitored: The AQI has been developed for eight pollutants – PM2.5, PM10, nitrogen oxides, sulphur dioxide, ozone, and carbon monoxide. The ministry has also taken additional steps to include lead and ammonia, that also have harmful effects over time.
  • Colour coded warning: AQI has been developed in relation to the Ambient Air Quality Standards and air quality has been classified into six bands and described simply as good, satisfactory, moderately polluted, poor, very poor, and severe. Each band has cut points of concentration with a colour code to visually express the level of severity that people can understand easily. This recognises the principle that from a public health standpoint, even air quality standards that are the regulatory targets to push action are not good enough. From that perspective, air quality is classified as good if the pollution levels are at least 50 per cent below the regulatory standards. This will be reported daily by the state pollution control boards.
  • Health advisory to raise public awareness: The government will now issue health alerts to people based on air quality index. Possible health consequences of each air quality band will be indicated separately to alert the vulnerable—especially the elderly, children, and those already predisposed towards heart and respiratory problems. This will also indicate health consequences for general public during severe smoggy episodes. For instance, good air quality days will have minimal impact. On days that are satisfactory, it may cause minor breathing discomfort to sensitive people. On severely polluted days there may be respiratory impacts even on healthy people, and serious health impacts with lung and heart disease and so on.
  • National implementation: AQI will be implemented nationally in cities with million plus population first and then the next rung in the next phase.

How Delhi fares on proposed AQI

CSE applied the proposed air quality index to PM2.5 levels in pre-winter months in Delhi (July 1 to October 15, 2014).

To test how the days in Delhi will rank once the proposed AQI is rolled out, CSE has applied the proposed index in three monitoring locations – R K Puram, Civil Lines, and Punjabi Bagh. Distribution of days ranked good, satisfactory, moderately polluted, poor, very poor, and severe varies quite widely across months, seasons and locations:

  • Delhi does record good air quality days with pollution levels 50 per cent below permissible level in some months. Their share needs to increase: Between July and October 2014, just before the onset of winter (that also includes rainy days), Delhi seems to have had several days when air pollution levels were 50 per cent below the standard. For instance, 7-8 per cent of the days in Punjabi Bagh during this period have recorded ‘good’ days. In R K Puram, 5 per cent in July, 33 per cent in August, 19 per cent in September, and 10 per cent of the days in October have been recorded as ‘good’. But Civil Lines, a known pollution hot spot, had only 4 per cent of the days in September that were‘good’.
  • Share of severe pollution days: the top bands vary significantly across months and locations: The number of severely polluted days, the top band in AQI system, increases as winter approaches. Punjabi Bagh has not experienced any severely polluted day during these four months. R K Puram has not experienced any severely polluted day in the months of July, August, and September, but 30 per cent of the days in October were severe. In Civil Lines, 21 per cent of days in July, 76 per cent in August, 11 per cent in September, and 100 per cent days in October were severe.
  • Pre-winter phase relatively better: A substantial number of days in most locations have met air quality standards during this period. In Punjabi Bagh, 21 per cent of days in July, 40 per cent in August and 29 per cent in September have met the standards (but none in October so far). In R K Puram, 21 per cent in July, 66 in August and 33 in September met the standards. It dropped to 10 per cent in October. In Civil Lines while 52 per cent of the days in July met the standard, it dropped drastically to 8 per cent in August and 7 per cent in September. None of the days could meet the standards in October. Clearly, as we are approaching the onset of winter in October, pollution is building up.

Says Roychowdhury, who was a part of the expert group which finalised the draft index: “All signs tell us that as winter is approaching, the share of days meeting standards is reducing rapidly. This is an opportunity to plan in advance with short-term effective measures to prevent severe smog during winter.”

In line with global action

India now joins the global league of countries like the US, China, Mexico, France and Hong that have implemented smog alert systems. These countries also implement pollution emergency measures to bring down the peak pollution levels. Indian cities need that roadmap as well.

  • Beijing: Similar public information system on air quality and health alert in Beijing has helped build public awareness and catalysed several changes. Beijing also has a pollution contingency plan. On red alert days, kindergartens, primary and middle schools are closed; about 80 per cent of government-owned cars are taken off the road; private cars are allowed on alternate days according to numbers plates; freight vehicles and those transporting material for construction sites are barred; polluting factories need to cut their emissions or shut down completely when the orange warning signal is issued; and construction sites have to halt excavation and demolition operations. On heavily polluted days, there is a ban on barbeques and fireworks. The 2013 smog forced Chinese cities to close some of the large factories. Smog episodes in Beijing have also led to restrictions on highway movement. Local governments in China are now liable to pay a fine if air pollution levels hit the critical mark.
  • The US: In US cities, Rule 701 of air pollution emergency contingency actions (for PM and ozone) states that during stage 2-3 level of alert, school officials, local and state law enforcement agencies must be informed; public safety personnel should discontinue prolonged, vigorous outdoor exercises lasting longer than one hour; those with heart or lung diseases should be informed to avoid outdoor activities. Industrial units must be asked to reduce combined emissions by at least 20 per cent of normal weekday operations. For vehicles, the rule asks to reduce fleet vehicle miles travelled by at least 20 per cent of normal week day operations; promotes ride-sharing and telecommuting. It also says that liquid or solid fossil fuels cannot be burned in electric power generating systems unless a force majeure natural gas curtailment is in effect. It also recommends that all non-emergency driving be discontinued.
  • Paris: During high pollution episodes, Paris authorities recommend drivers to postpone trips to Paris or bypass Paris city; use public transport; organise car-pooling; minimise combustion of high sulphur fuels in industry; and curtail industrial operations. During severe smog episodes, diesel cars are not allowed in the city.
  • Mexico: Phase 1 pollution alert requires cutting down of 30-40 per cent of industrial pollution; halting of 50 per cent of government vehicles; stopping of most polluting vehicles; and exemption of alternative fuel vehicles from restrictions. In phase 2 alert, schools are closed and one-day-a-week ban on vehicles is extended to two days. A phase 3 alert leads to closing down of industry in addition to other curtailments.

CSE demands

The proposed air quality index is an important step forward to push aggressive and time-bound action in Indian cities to meet clean air standards and reduce public health risk, says Roychowdhury.

  • This proactive move should be taken forward quickly and implemented during the coming winter when pollution levels peak and health impacts aggravate.
  • Expand and improve air quality monitoring network across cities to generate real time air quality data to enable its implementation and feed the public information system. Ensure good quality monitoring.
  • Implement dissemination of AQI and health advisory through media and other communication channels.
  • Frame pollution emergency measures to reduce daily peak pollution.
  • Prepare short and medium term action plan in all cities to meet the air quality standards.
  • Initiate public awareness campaign to build support for pollution emergency measures

National Air Quality Index 2014

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