Introduction to the A&WMA 2004 Critical Review Megacities and Atmospheric Pollution

摘要

More people throughout the world are moving from rural to urban areas for better jobs, access to city services, cultural and educational opportunities, and more stimulating social interaction. Human settlements are expanding both horizontally and vertically to accommodate this influx, transforming themselves from villages to towns, towns to cities, and cities to megacities. Megacities, metropolitan areas with populations exceeding 8-10 million inhabitants, generate atmospheric pollution that affects public health, deposits on surfaces, causes urban and regional haze, and alters the earth's climate. Yet, with appropriate planning and the application of new technology, large and dense population centers can reduce atmospheric pollution and its effects through mass transit systems, cogeneration of electricity and heat, and recycling. Such planning must consider the local, urban, regional, and global effects of pollutants. It must treat gas and particle emissions from a variety of sources as a single entity, rather than as separate pollutants. It must recognize and address urban emissions that cross jurisdictions and international borders. The influence of large urban areas on atmospheric pollution must also be balanced against that of nonurban contributors to determine optimal emission control strategies.