For the city of Delhi, an air quality index methodology was proposed and applied for six criteria pollutants - PM10, PM2.5, CO, NOx, SO2, and Ozone and analyzed for trends in the past three years of data. The AQI is reported on a scale of 0 to 500 and subdivided into six colored bins for easy understanding of the common person and the media. The results are not surprising, but the trends are alarming, given the Commonwealth Games are just around the corner to host. A complete report on the methodology and analysis is available as part of the SIM-air working paper series.

 

Between July 2006 and July 2010, the health standards are exceeded more often in Delhi than not - only on 37 percent of the days the standards were met, in the form of AQI. Most of often, the worst is observed during the winter months, starting in October and ending some time in February of the next year. The best air quality is often during the monsoon months, when most of the pollution is washed off in rain and the skies are cleaner and clearer.

 

Over the past four years, the month of October, which is crucial in the coming weeks, to host clean and clear Commonwealth Games, is getting worse. The Figure below presents a summary of the frequency of AQI colors observed for the month of October from 2006 to 2009. The value of 150 is considered threshold value for healthy air.

 

 

 

The growing number of vehicles and the demand for urban infrastructure is choking the cities pollution levels. The air quality in Delhi improved in the early 2000's due to a number of interventions, including the large scale conversion of the bus fleet and the 3 wheeler fleet from the conventional gasoline and diesel to compressed natural gas. However, the large increase in the demand for personal transport and construction activities reversed the trends.

A major intervention that Delhi is counting on is the extension of the metro rail system, to shift the motorized transport trends to the metro rail. The expected level of shift is uncertain, which depends on a number of factors, but it will very beneficial as the impact of air pollution on the human health and the ecosystem is increasingly been linked to the growing transport sector.

Following a half day workshop on May 10th, 2010, by Center for Science and Environment, where representatives form the government and academia were present to discuss options to better air quality during the 2010 Commonwealth Games, here is a list of 7 proposed measures

 

While, these measures are more transport centric, city needs to fast implement multi-sectoral solutions to achieve better air during the Games. In case of Beijing, stringent regulations and policy measures were implemented, months in advance, to ensure clean air days before and during the 2008 Olympic Games. However, this remains a challenge in the Delhi authorities. Given that the Delhi Government can neither shut down industries nor stop half their in-use vehicle fleet during the CWG 2010, a series of innovative interventions could be introduced for fast and effective air quality management. Such as