Asia is undergoing rapid urbanization resulting in increasing air pollution threats in its cities.The contribution of megacities to sulfur emissions and pollution in Asia is studied over a 25-year period (1975–2000) using a multi-layer Lagrangian puff "Atmopheric Transport Modeling System (ATMoS)". An urban scale analysis of sulfur pollution for four megacities — Shanghai, and Chongqing in China; Seoul in South Korea; and Mumbai (formerly Bombay) in India is presented. If pollution levels were allowed to increase under business as usual scenario, over 30 million people in these cities alone would be exposed to levels in excess of the WHO guidelines.

* Publication in Atmospheric Environment (2003)