(Representative Image/AP photo)

New Delhi: The Delhi Pollution Control Committee (DPCC) informed the National Green Tribunal (NGT) on Wednesday that air quality had improved in the first week of the odd-even phase 2 but then deteriorated possibly due to meteorological factors, crop fires in the neighbouring states and landfill fires in the city.

DPCC submitted its findings in a detailed report based on the data from four automatic stations and 74 other locations as well as industrial areas in the capital. The bench asked Central Pollution Control Board (CPCB) and all other parties to file their reports on the odd-even scheme between April 15 and 30 by Friday.

The tribunal asked the Delhi government if the drive was worth investing in. “Wouldn’t it be better if the money spent on the scheme was utilised for something else?” Earlier, too, NGT told the government to explain why it was not emphasising on pollution sources like dust and burning waste the way it had been focusing on the odd-even scheme.

DPCC divided their monitoring of four automatic stations at RK Puram, Mandir Marg, Punjabi Bagh and Anand Vihar into four phases—April 6 to 14, April 15 to 21, April 22 to 30 and May 1to 6, covering the days before and after the road rationing scheme.

The average PM2.5 concentration before odd-even ranged from 31 to 276 micrograms per cubic metres (µg/ m3) while the wind speed varied between 0.95 and 3.23 metres per second (m/s). Between April 15 and 21, the range was 43 to 205 µg/m3 and the wind speed 0.78-3.08m/s. But in the second week, PM2.5 ranged from 53 to 328 µg/m3 while the wind speed had reduced to 0.721.68m/s. However, just after the odd-even 2, the PM2.5 level fell between 29 and 262 µg/m3.

If one considers the averages for the week, it was 89µg/m3 before the odd-even 2, but spiked to 111in the first week and further to 154 in the second week. The DPCC data for PM10 and nitrogen dioxide (NO2) reflect similar trends. “The analysis of the data shows the total period was highly influenced by metrological parameters like wind speed, wind direction, ambi ent temperature and others,” the DPCC report said.

It is observed that “local and trans-state movement of pollutants also influenced the air quality of Delhi during odd-even. The probable factors are crop residue burning in Haryana and Punjab, local fires and landfill fires in Delhi”.

DPCC’s monitoring of 74 locations in central Delhi and border areas, and on Inner Ring Road and Outer Ring Road showed a marginal decrease in PM2.5 levels in central Delhi and on Inner Ring Road compared to the other two areas in the first week but April 22 onwards, a jump was seen at all locations that dropped only in the first week of May.

