Abstract Unplanned urbanization and industrialization are causing deterioration of the environment and quality of life in the developing countries. It is essential to assess the spatial distribution of air quality and its impact on human beings in the urban region. A large data base is required to estimate the human exposure to air pollution. The Geographical Information System (GIS), which is especially suited for handling data with large spatially distributed features, is a valuable tool for estimation of population exposure. In this study an indigenously, developed GIS package GRAM has been used to assess the exposure and health risk of the population of the Greater Bombay region from atmospheric pollutants. The population and the built-up area are growing rapidly, and the concentration of air pollutants is large in the eastern and central parts of the city. Interpolated maps of three pollutants have been created using GIS to calculate the Air Quality Index (AQI). Maps of population density and population growth give an idea of the pressure of population on the land. The final map generated by overlaying the AQI map and population pressure map helps to demarcate five pollutant risk zones in Greater Bombay. This map is useful for developing various air pollution management strategies. Thus GIS can be used as an efficient tool for environment planning.