Abstract Number: 15 Working Group: Source Apportionment
Abstract Mumbai with its large population and mixed land use characteristics poses a major challenge to understand its sources of air pollution. Each residential area or industrial area has its own specific feature with regard to type of sources, local meteorology and activity profile. A comprehensive sampling of PM10 was undertaken for four representative sites during December 2007- February 2008. Samples were analyzed for 19 elements, 7 ions besides organic and elemental carbon. Samples were analyzed for elemental concentrations by ICP-AES; EC/OC using DRI’s Thermal/Reflectance Optical Carbon Analyzer and ions using Ion Chromatograph. Factor analysis (FA) has been carried out prior to Chemical Mass Balance (CMB) modeling with a view to understand a priori major components. The CMB model is one of several receptor models that have been applied by several researchers to air quality management. Using major source profiles developed first time in India under Central Pollution Control Board’s, Six cities air quality studies, receptor model CMB 8.2 was applied to sampled data for all four sites to understand the sources and their contribution locally. Results of industrial site indicate that major sources are soil dust (30%), solid waste burning (21.3%), secondary aerosol (12.3%) and Heavy duty diesel vehicles (10.4%). At Khar, an upper class residential area, the major sources are vehicles (41.8%), soil dust (37.7%), secondary aerosol (10.1%) and wood combustion (9.1%). At Dharavi, a lower class residential site the major sources are soil dust (47.9%), vehicles (25.6%), marine aerosol (9.6%) and secondary aerosols (10.5%). Vehicular, soil dust and marine aerosol have been found to occur at all four sites as more ubiquitous sources by both CMB and FA. Another source is the indirect source secondary aerosol observed at all four sites by CMB model.