Megacities and Atmospheric Pollution

摘要

The following is a discussion of the 2004 A&WMA Critical Review of megacities and their effects on air quality and pollution-control policies. In the Review, Drs. Mario J. Molina and Luisa T. Molina examined nine large metropolitan areas to identify similarities and differences that affect pollution and its adverse effects. They found that cities in developing nations have higher pollution levels than cities in wealthier nations, despite the greater use of public transportation by their residents. These cities do not have the infrastructure needed to deliver clean fuels to homes for cooking and heating, resulting in greater use of solid coal and biofuels. They also contain older vehicles with higher exhaust emissions and unpaved or poorly maintained roadways that suspend dust. Roadways and public transportation systems are congested and misuse of fuels is common. Cities in developing countries are concerned about loss of employment and economic benefits associated with polluting industries. The Review recommends the use of integrated assessment tools to evaluate emission reduction measures in the world's megacities. These include accurate emission estimates, source and receptor models to identify pollution sources, and monitoring networks tailored to compliance, source assessment, forecasting, and tracking of reasonable progress. The Review concludes that pollution control efforts are often hindered by insufficient local expertise and resources, and by a lack of commitment to air quality management and control. Trained experts, working with local stakeholders, politicians, and the population at large, must take the initiative to institute changes. With appropriate planning, megacities can efficiently address their air pollution problems through integrated control strategies that are effectively implemented and embraced by the public.