COMPARATIVE INVESTIGATION OF AIR QUALITY INDEX (AQI) FOR SIX INDUSTRIAL CITIES OF IRAN

Air pollution can affect human health, plants, buildings and environment in many ways. Hence the aim of this study was determined to compare the air quality in six industrial cities (Tehran, Tabriz, Mashhad, Urmia, Ahvaz and Irak) by using air quality index (AQI) in 2011-2012. In order to AQI determination, hourly data of five criteria pollutants taken from the environmental protection agency of each city and validated according to the WHO guidelines. The valid data converted to standard concentrations according to the guidelines and based on standard table and equation, daily AQI was determined for each pollutant. The highest value between the calculated indexes for all of the stations and the pollutant that was responsible for this index, introduced as a final index and responsible pollutant of day, respectively. The findings showed that in Tehran, Tabriz, Mashhad, Urmia, Ahvaz and Irak in 341, 139, 347, 28, 162 and 81 days of year, the AQI was over the Environment Protection agency of Iran's standard, respectively. Also in all of the cities the particulate matter (PM) was the main responsible pollutant. Comparing the air quality in these cities indicated that Urmia and Irak have average condition but the other cities conditions are far from the ideal.