Air quality in most of the Indian cities is deteriorating at
a fast pace due to increasing vehicle fleet, with the present
figure crossing 35 million55. To monitor the air quality
changes, a nationwide programme, National Ambient
Air Quality Monitoring (NAAQM) was initiated in 1984.
As on 31 March 1995, the network comprised 290 stations
covering over 90 towns/cities distributed over 24 States
and 4 Union Territories. The network is operated through
the respective State Pollution Control Boards, the National
Environmental Engineering Research Institute (NEERI),
Nagpur and also through the Central Pollution Control
Board (CPCB). The pollutants monitored under NAAQM
are sulphur dioxide, nitrogen dioxide and SPM, besides
meteorological parameters like wind speed and direction,
temperature and humidity. Recently, in certain major cities,
regular PAHs in ambient air are also being included in
the assessment. Annual data on air-quality parameters of
various places are available at the CPCB website56. Station-wise
reports on air quality parameters such as SPM,
SO2 and NO2 published by NAAQM are reproduced in
‘The citizens fifth report – Part II: Statistical database’57
.
SPM data of some important cities are reproduced in Table
1. Levels of RSPM are not available in the NAAQM data
until 1995.