New Delhi, Apr 14: A day before the second phase of 'odd-even' car rationing scheme begins, a green body today said Delhiites are at present breathing "better quality air" as particulate matters which cause respiratory diseases are under prescribed limits.
The Energy and Resources Institute (TERI), which analysed air quality data of April 13, said although PM2.5 and No2 were under limits, PM10 levels that consist of particles from both natural and anthropogenic sources are still higher than the prescribed standard.
It said while limited reductions were observed in air pollutants during the first phase of the scheme in January, contribution from outside sources will be an important factor this summer.
"Contribution from outside sources becomes important in this season as the wind blowing from North-west direction may carry pollutants towards Delhi... Also, downwind towns in NCR like Gurgaon, Ghaziabad and Noida show higher levels than Delhi, with contributions from Delhi's emissions," it said.
TERI said it will release regular updates on air quality with analysis during the second phase of odd-even scheme from April 15 to April 30 in Delhi and nearby towns using its own monitoring devices.
"Some places in Delhi are breathing relatively better quality of air at present, as PM2.5 (particles with diameter less than 2.5 micrometre) and NO2 (oxide of nitrogen) concentrations, responsible for respiratory diseases and impaired lung function, are close to or less than the prescribed standards at most places.
"Higher wind speeds and enhanced vertical thermal diffusion are the primary reasons leading to better dispersion of pollutants released from different sources," TERI said in a statement.
It said PM2.5 and NO2 concentrations were, however, not within the limits at RK Puram and Anand Vihar. TERI will carry out a trend analysis of PM10, PM2.5 and NO2 at nine locations -- Mandir Marg, R K Puram, Punjabi Bagh, Anand Vihar, Bahadurgarh, Lodhi Road, Ghaziabad, Gurgaon and Noida.
The objective is to analyse the effect of 'odd-even' scheme on air pollutant concentrations.
"TERI analysed the effects during the last phase and concluded that congestion levels were reduced but limited reductions were observed in air pollutant concentrations," it said.