While it was a strong steady breeze which allowed Delhiites to breathe easy on Diwali night as it swept away the smoke emanating from the fire-crackers, the Delhi Government on Friday could not resist taking credit for the reduction in air pollution levels.
Seeking to credit the fall in air pollution to its awareness campaigns, Delhi Environment Secretary Keshav Chandra said the air quality has improved with the active cooperation of citizens, especially, children who made extra efforts to contain use of crackers during Diwali festival on the appeal of Chief Minister Sheila Dikshit.
What was conveniently overlooked was the fact that whenever the wind velocity is high the smoke gets dissipated and as a result the air pollution levels are recorded at lower levels. The same held true on Thursday as the strong breeze – recorded as “calm” by the Indian Meteorological Department at its Safdarjang observation centre -- made it even difficult to keep the ‘diyas' and candles burning in the open.
Though people struggled to even light the matchsticks in the strong wind, the Delhi Government said it were the initiatives taken by the Department of Environment and Forests under the able guidance of the Chief Minister during the last 12 years that have generated an atmosphere conducive to better air quality.
Mr. Chandra said efforts include the switch-over from diesel to CNG for the public transport system and commissioning of Delhi Metro. He said the setting up of more than 2,000 eco clubs in schools, involving RWAs in environmental issues and launching forceful campaigns through FM and print media had also facilitated a positive change in the mindset of the citizens resulting in an environmental success story.
The Secretary said in general the concentration of the pollutants has shown a decrease this year compared to last year. This, he said, could be attributed to the concerted and sustained anti-fire crackers campaign.
There has been far less concentration of the pollutants as measured and monitored scientifically in respect of four parameters -- gaseous parameters of SO2, NO2 and carbon monoxide and particulates which include PM10 and PM 2.5.
The Delhi Pollution Control Committee (DPCC) has been conducting the assessment of ambient air quality during Diwali since 1988 and since last year has also been undertaking Real Time Ambient Air Quality Monitoring at five locations – Indira Gandhi International Airport, Civil Lines, Mandir Marg, R. K. Puram and Punjabi Bagh for different parameters which include gaseous and particulate pollutants.
As per the data recorded in the 24 hours from 6 a.m. to Thursday to 6 a.m. on Friday, the average concentration for CO ranged from 1.2 miligram per metre cube to 2.05 mg/metre cube. While the values at all the five locations were within limit, the minimum average value was observed at Punjabi Bagh and the maximum at Civil Lines. In comparison, the average value of carbon monoxide during Diwali last year ranged from 0.87 mg/m3 to 9.75 mg/m3.
As for oxides of nitrogen (NO2), the average concentration this year was comparatively higher that on the previous Diwali and varied from 59.64 micro gram /m3 to 133.4 micro gram/m3 in comparison to 64 micro gram/m3 to 95 micro gram/metre cube last year. At R. K. Puram, the level was higher this year in comparison to the last.
Similarly in the case of sulphur dioxide the average concentration this year was between 34.58 micro gram/m3 and 42.9 micro gram/metre cube as against the range of 26.0 micro gram/m3 to 73.5 micro gram/metre cube last year.
Both the parameters of particulate matter also showed a marginal decline this year. The average concentration of PM10 ranged from 336.6 micro gram/m3 to 597.3 micro gram/metre cube as against 496 micro gram/m3 to 663 micro gram/m3 during the previous Diwali.