A comparative study of air pollution in Indian cities.

Rapid and unplanned industrialization and urbanization has resulted in the deterioration of India’s air quality according to air-quality monitoring carried out in seven major Indian cities in industrial and residential areas between 1995 and 2000. Suspended particulate matter (SPM) levels in Indian cities are in the range 50 to 550 μg/m3. NOx values are high in Delhi’s residential areas, with values of 33 μg/m3 in 1995 and 34.6 μg/m3 in 2000, while in an industrial area values of 29.4 μg/m3 were found in 1995, increasing to 33.7 μg/m3 in 2000. SO2 values are very high in Pune city, ranging from 43.3 μg/m3 in residential to 43.69 μg/m3 in an industrial area in 2000.