PRELIMINARY DETERMINATION OF AIR QUALITY INDEX (AQI) ALONG BUSY ROADS IN KARACHI METROPOLITAN, PAKISTAN

Present study was carried out to determine the concentration of ambient air quality in terms of air born particulate matter (PM10) at 10 different locations on the busy roads in the commercial, residential and industrial areas of Karachi city. Concentrations of particulate matter were used to calculate the results in the form of Air Quality Index (AQI). At each location, the study was carried out continuously for a period of 24 hours in summer and winter season during the year 2014. Results along the selected sites show that at most of the sites have very poor to hazardous AQI categories. Level of ambient air quality is aggravated at traffic congested sites and the sites proximal to industries where pollution level is highly worsen and exceeding the proposed standard limits of US-EPA. Diesel driven heavy duty vehicles (buses and trucks) and two stroke auto rickshaws are the most polluting vehicle emitting high concentration of pollution in the atmospheric air. The results show that the level of PM10 at all the selected sites excluding residential area of PIB colony and Gulshan-e-Iqbal, exceeds the permissible limits as specified by US-EPA. This high concentration of pollution is very harmful for human health to the residents