Source apportionment of air pollutants in Hyderabad City

Hyderabad is the state capital of Andhra Pradesh and fifth largest metropolis of India. The increased economic activity has encouraged migration on a massive scale and expanded the horizon of the city making the erstwhile industrial areas and suburban places an integral part of the city. The population of the city is currently 7 million and is growing rapidly. The increased horizon of the city needs an effective transit system to cater to the transport demand of the various sections. The failure of public transport coupled with personal preference has resulted in proliferation of personalised, private and Para transit modes (3 and 6 seat autos) to a fleet of over 1.7 million vehicles. This has resulted in increasing air pollution. The air pollution problem has triggered various actions by the government. The source apportionment of air pollutants in Hyderabad city is taken up by Andhra Pradesh Pollution Control Board for better management of air pollution with technical assistance by US Environmental Protection Agency, World Bank, US National Renewable Energy Laboratory and Desert Research Institute. Sampling to characterise the problem was performed during three seasons using low volume samplers at three locations simultaneously. Size resolved aerosol mass (PM10 and PM2.5) and chemical characterisation were performed. The results presented here are concentrated in the source identification and apportionment of fine and coarse particles in the winter season of 2005. The concentration of particulate matter of size less than 10μm aerodynamic diameter (PM10) is exceeding the national standards by 50% on an average for 24 hour PM10 concentration. PM2.5 is 50% of the PM10 on an average at all the three stations. The ratio between Elemental Carbon (EC) and Organic Carbon (OC) is in the range of 1.7 to 2.6 from high traffic zone to the lower traffic areas. The results were subjected to Chemical Mass Balance (CMB) model in order to determine the relative source contributions. Motor vehicles were found to be the major sources of the PM (approximately 50%) followed by re-suspended dust from paved and unpaved roads (30%) and biomass burning (11%).