%0 Journal Article %A Sharma, Mukesh %A Pandey, R. %A Maheshwary, M. %A Sengupta, B. %A Shukla, B. P. %A Mishra, A. %D 2003 %I Begell House %N 3 %P 15 %R 10.1615/InterJEnerCleanEnv.v4.i3.50 %T AIR QUALITY INDEX AND ITS INTERPRETATION FOR THE CITY OF DELHI %U https://www.dl.begellhouse.com/journals/6d18a859536a7b02,4d21a0ce47bfea67,1960fc53792ae201.html %V 4 %X An Air Quality Index (AQI) is proposed for the City of Delhi for simplified public information and data interpretation. A maximum operator concept is used to determine the overall AQI; maximum value of subindices (of each pollutant) is taken as the overall AQI. The mathematical functions for calculating subindices are proposed after considering heath criteria of the United States Environment Protection Agency (USEPA) (Federal Register, December 9, 1998) and Indian air quality standards. The pollutants included in the index are: SO2, suspended particle matter (SPM), O3, NO2, PM10, and CO.
The investigations into data interpretation vis-a-vis the air quality index for Delhi city have shown that the air quality worsens (Very poor to Severe) in winter months and also during the presummer months. The presummer months like March, April and part of May are characterized by dusty winds resulting in high SPM concentration. The air quality improves in monsoon and postmonsoon periods (Good to Moderate). The SPM was the responsible pollutant for index value over 95 percent of the time at most locations. Nevertheless, at a traffic intersection, the critical pollutant varies and depending on the time of year, it could be SPM, CO, or PM10. It suggests that for large cities like Delhi the critical pollutant will not necessarily be SPM, and information on other pollutants is also required for a proper representation of air quality through AQI. %8 2003-09-01