Dr. Mukesh Sharma
Professor, Department of Civil Engineering
BASIS OF INDIAN AIR QUALITY INDEX
(IND - AQI)
Air is the prime resource for sustenance of life. With the technological advancements, vast amount of data about ambient air quality is generated to know the quality of air environment and to administer the appropriate corrective actions wherever necessary. Such an endeavor would result in encyclopedic volumes of data which may neither give a clear picture to a decision maker nor to a common man who simply wants to know how good or bad the air is. As for the general public, the questioner usually will not be satisfied with raw data, time series plots, statistical analysis and other complex findings pertaining to air quality. To address the above concerns, IIT Kanpur through a sponsored project from the Central Pollution Control Board, Delhi has proposed the Indian Air Quality Index (IND - AQI) in a simple and lucid terms.
linear function is used relating the actual air pollution concentrations
(of each pollutant) to a normalized number. The basis for these linear
functions (for this study) is arrived after considering such functions
adopted by other countries (USEPA, 1976 and 1998; UK, 1998; Malaysia, 1997;
GVAQI, 1997; Ontario, 1991; ORAQI, 1970). The pollutants included for the
proposed IND - AQI are SPM, SO2, NO2, PM10,
CO and O3. The following table presents the summary of the break
point concentrations and AQI values for India (proposed) for all pollutants.
Since all the pollutants are not measured under the National Ambient Air Quality Monitoring Program, it is necessary that at least three pollutant concentrations must be available to calculate and report the index. The over all AQI is based on maximum operator system where the maximum value of sub-index becomes the AQI. To reflect the attainment of NAAQS, the AQI is referred to as Good between the range 0 - 100. For the second break point (at the standard of USEPA), the AQI takes the value of 200 and referred to as Moderate. In absence of any other pollutant of any other pollutant health criteria in India, rest of categorization of Index is based on the USEPA Federal Episode criteria and Significant Harm Level.
IND-AQI is primarily a health related index with the following descriptor words: "Good (0 - 100)", "Moderate (101 - 200)", "Poor (201 - 300)", "Very poor (301 - 400)", "Severe (401 - 500)".
Although this website does not forecast the AQI for coming days, it however, does include the possible health effects so that the people can tke precautions; as in all likelihood the AQI is not going to change significantly on next day.
Features of Website:
A website is
developed for display of nation-wide air quality index. The display system
script. As the air quality data become available, online calculation of
AQI is carried out and displayed as an Air Quality Meter showing index
value (with a pointer) with animation on the screen. The website is comprehensively
designed to indicate the pollutant responsible for index and the pollutants
exceeding the standards. The developed website facilitates for inter/intra
city comparison of AQI using multiple windows for online as well as historical
data of air quality. The general public can access the information through
internet and other media agencies like newspaper, TV, radio can also download
the information and disseminate the information.
(1997). Greater Vancouver Regional District Air Qulaity and Source Control
Department, Burnaby, BC, Canada