With the increased industrial and commercial activities in the vicinity of major cities, the quality of the ambient air is being affected by emissions from the industries and from the ever increasing vehicular population. As per the provision of Air (Prevention and Control of Pollution) Act, 1981, the entire state of Tamil Nadu has been declared as an air pollution control area.
Ambient Air Quality Monitoring Programme
Tamil Nadu Pollution Control Board is operating eight ambient air quality monitoring stations in Chennai, Three ambient air quality monitoring stations in Thoothukudi, Three ambient air quality monitoring stations in Coimbatore ,One ambient air quality monitoring stations in Salem, Three ambient air quality monitoring stations in Madurai, Five ambient air quality monitoring stations in Trichy, Three ambient air quality monitoring stations in Cuddalore and Two ambient air quality monitoring stations in Mettur under National Air Quality Monitoring Programme (NAMP) funded by Central Pollution Control Board.
All the stations are functioning on 24 hours basis, twice a week. The samples collected from NAMP stations are analysed for the Respirable Suspended Particulate Matter (RSPM) (RSPM is particulate matter less than 10 microns) and gaseous pollutants such as Sulphur di oxide (SO2) and Nitrogen di Oxides (NO2).
The National Ambient Air Quality Standards prescribed is given below:
Area
Annual average concentrations of pollutants in µg/m3
SO2
NO2
RSPM
Industrial Residential, Rural & other areas
50
40
60
All the monitoring stations under NAMP, functions on a 24 hour basis, twice a week. The samples collected from NAMP stations are analysed for the RSPM and gaseous pollutants sulphur dioxide and nitrogen dioxide.