The national Capital’s Air Quality Index (AQI) improved slightly, dropping from the ‘very poor’ to ‘poor’ category on Sunday, as wind speeds picked up marginally.
However, even though the overall AQI improved by a few digits, 15 of the 36 monitoring stations in the city recorded ‘very poor’ AQI values. Further, air quality levels are set to deteriorate over the coming week, due to unfavourable meteorological conditions, Central Pollution Control Board (CPCB) officials said.
Delhi’s AQI on Sunday stood at 292, against Saturday’s 324.
The AQI in Faridabad and Noida remained in the ‘very poor’ category. Pollution in the region has barely improved, despite the implementation of the graded response action plan (GRAP), which came into effect on October 15, to counter ‘poor’, ‘very poor’ and ‘severe’ air pollution levels in Delhi-NCR.
Some of the measures being implemented across the city for ‘poor’ and ‘very poor’ categories include sprinkling water on major stretches, mechanical sweeping of key roads, as well as a ban on the use of diesel generator sets. An AQI between 0 and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’ and that between 401 and 500 is categorised as ‘severe’.
“The improvement in the air quality is due to wind speeds marginally increasing. Good winds help pollutants disperse in the air. However, according to inputs from the Meteorological Department, winds are likely to remain calm over the weekend, which, coupled with farm fires and local emissions, is expected to trigger a spike in pollution levels,” a senior CPCB official said.
Additionally, PM 10 and PM 2.5 levels — the most prominent pollutants in Delhi-NCR — stood at more than double the safe levels, at 306.1 and 152.3 micrograms per cubic metres, respectively. The safe standard for PM 10 is 100 micrograms per cubic metres while for PM 2.5 it is 60.
If air quality drops to ‘severe’ for 48 hours, measures such as banning construction activity and entry of trucks (except essential commodities) can be taken. The state government may also consider implementing the odd-even road rationing scheme.