The Delhi Pollution Control Committee (DPCC) has conceded that pollution level during second phase of even odd between April 15-30 was not at all satisfactorily as average concentration of PM 10 concentration of PM10 at different stations is varied from 152-376µg/m3 while average concentration of PM 2.5 varied from 31-276µg/m3. It said that pollution levels increased due to dip in wind speed and farm fires from April 22, in line with the findings of green body CSE.
According to report, the data analysis also shows that trend decreased that particulate matter was decreased during pre and post even odd scheme. The first week of odd-even II saw a “decrease” in pollutants but air quality fell thereafter owing to reduced wind speed,wind direction, ambient temperature, crop burning, with blazes at landfill sites and forest fires in Uttarakhand being added factors.
The report also blamed that the analysis of the data generated before, during and after the event shows that the total period was highly influenced by metrological parameters like wind speed, wind direction, ambient temperature.
“It is also observed that local and trans-state movement of pollutants also influenced the air quality of Delhi. The probable factors are crop residue burning in Haryana, Punjab, local fire in Delhi including fire in land fill sites and Uttrakhand fire might also had effect on ambient air quality,” the report said.
The three-tier monitoring was done at the level of the six fixed stations, through the application of light scattering technique at 74 locations and manual monitoring at 20 residential, 15 industrial locations. The report will be submitted to National Green Tribunal on Monday. Earlier the NGT has directed DPCC and Central Pollution Control Board (CPCB) to furnish reports on data of ambient air quality in Delhi recorded during the recently concluded second phase of odd-even scheme.
The average value of PM 2.5, recorded at 89 micrograms per cubic metre (ug/m3) between April 6-14, went up to 111 during the first week of the scheme and 154 in its second week.