Causes
Poor air quality in urban areas is mainly caused by combustion of fuel by industries, households and vehicles, as well as forest fires and dust. Pollutants are either emitted directly or are the result of chemical reactions.
Pollutants provoke a wide range of negative health effects such as lung and heart malfunctions, bronchitis or asthma. Cancer risk increases as the air quality degrades.
Inadequate urban planning, the establishment of satellite cities and the preference of individual over public transport result in increasing motor vehicle mileage which in turn increases the level of air pollution in urban conglomerates.
Fast growing industries applying outdated technology, the use of poor quality fuel or coal, the lack of land-use planning allowing heavily polluting factories to produce in urban dwelling centres also contribute to poor air quality.
If air pollution combat takes place at all, it is certainly in metropolitan areas.