The world's cities are choking on pollution from traffic and industry. With the health of over 1.6 billion people under threat, poor urban air quality is fast becoming one of them most pressing environmental problems of our times. Smog Alert examines the causes and scale of urban air pollution, identifying who is most at risk, and what particular health risks various pollutants pose. It then considers an effective framework for air quality management, so that national and city authorities can consider what pollution control polices and measures are needed to deliver healthy urban air quality, and to sustain it in the future. Having established the background and framework, the book examines the existing and alternative measures to monitor and combat the declining air quality. It assesses smog alert systems; the potential for cleaner car and fuel technology; sustainable traffic management and public transport policies; and methods of controlling both industrial and residential emissions. Detailed case studies illustrate the severity and breadth of the problem - from the first serious photochemical smogs in Los Angeles to the dire warning offered by Mexico City; and from London (the city which coined the word 'smog') to Athens' pollution phenomenon, the 'nefos'. Drawing on the lessons learned from past experience, Smog Alert provides a comprehensive analysis of how health air quality may yet be achieved in the world's cities.