According to the Economic Survey of Delhi 2014-15 the outdoor air quality has deteriorated over the years with the presence of particulate matters reaching alarming levels mainly due to vehicular and industrial emissions.
The PM10 (particulate matter) levels sharply rose from 282 µg/m3 (micrograms per cubic metre) in 2013 to 318 Âµg/m3 in 2014 while the standard level is said to be 60 µg/m3.
Particulate matter is a mixture of extremely small particles and liquid droplets like acids, chemicals, gas, water, metals, soil dust particles, etc, the measurement of which gives an idea of the pollution of a city.
In 2010, 2011 and 2012, the corresponding figures were 249, 281, and 293 µg/m3.
Concentration of PM2.5 varied from 125 µg/m3 to 191 µg/m3 over the last year as opposed to the annual standard of 40 µg/m3. The minimum was observed at Mandir Marg and maximum at Anand Vihar.
According to the World Health Organisation, particles with a diameter of 10 microns or less such as PM2.5 and PM 10 are severely health damaging due to their ability to travel deeper into the respiratory system.
The value of Carbon Monoxide (CO) in 2014 varied from 1.28 mg/m to 2.64 mg/m. The minimum was observed at Mandir Marg and maximum at Civil lines. Except Civil Lines, at all other locations, CO is under the prescribed standard of 2 mg/m3.
The annual average concentration of Nitrogen Dioxide (NO2) at all the monitoring locations also exceeded the prescribed standard of 40 Âµg/m3. In 2014, the average value was 79µg/m3.
The minimum value was observed at RK Puram and maximum at Punjabi Bagh.
The survey report said that besides human and environmental damage, pollution has resulted in “economic damage” as well, and held vehicular pollution as the main source of air pollution in Delhi.
It is estimated that air pollution generated from industrial activity in Delhi is about 20 per cent of total air pollution, it said.