GAW Report No. 205 - IGAC Project

CHAPTER 3 - ASIATable 4 - A summary of the emissions inventory (Tons/yr) for 2010 for NCR of Delhi, IndiaAir Quality Index for DelhiApplied methodologyThe methodology to calculate the air quality index (AQI) is presented below, along with thesupporting data for various ranges (Table 5).WhereCONC = concentration of the pollutantAQI = air quality index for the pollutantBP hi = the breakpoint that is greater than or equal to CONCBP lo = the breakpoint that is less than or equal to CONCAQI hi = the AQI value corresponding to BP hiAQI lo = the AQI value corresponding to BP loThe break point concentrations (high and low) are adjusted to the national ambientstandards of India for each of the pollutants [NAAQS, 2010]. The AQI ranges are adjusted with 150as the threshold, corresponding to the ambient standard for that pollutant. This is not an official AQImethodology for India, but an attempt to consolidate the available information and put together areasonable methodology based on applications from across the world.Applications of the methodology in various in cities across the world and how the informationis utilized for public awareness is presented in Guttikunda [2010c].Table 5 - The applicable ranges for AQI methodology for Delhi, India83