Air pollution levels in the megacities of Asia show a stabilizing trend but still exceed World Health Organization
guidelines. Studies also show poor air quality, not only in the megacities of Asia, but also in smaller cities with
populations of 200,000 to 1.5 million. While megacities often receive support for improving air quality; similar

The air pollution is a growing problem in a number of cities around the world. Over the years, starting from the days of the infamous London smog and Los Angeles smog episodes, the cities around the world have established programs to better understand the air pollution sources and facilitated ways to control the pollution.

Policymakers in rapidly growing urban areas increasingly recognize that addressing air quality issues is an urgent priority. The developing countries should aspire to imitate the air pollution modeling systems, irrespective of the modeling limitations.

Results of ambient air quality monitoring carried out during 2008 at various monitoring stations under National Air Quality Monitoring Programme by the CPCB.