New Delhi / Air quality may slip to 'very poor' by Sunday in Delhi

Delhi’s air quality slipped further in the ‘poor’ category on Friday due to slowed winds and crop residue burning in Haryana and Punjab, with pollution monitoring agencies predicting the Air Quality Index (AQI) to plunge to ‘very poor’ levels by Sunday.

On Friday, the 24-hour average AQI was 216 – considered ‘poor’ — according to Central Pollution Control Board. The continued spike in pollution levels comes a day after Delhi-NCR’s air quality deteriorated to its worst level in nearly three months -- the AQI hit ‘poor’ category at 211.

The System of Air Quality and Weather Forecasting and Research (Safar), a unit of the Union ministry of earth sciences, said in its forecast that incidents of crop residue burning have significantly increased in the past 24 hours and they will now start to heavily influence Delhi’s air.

“So far the effect from burning of stubble in Punjab and Haryana in Delhi is just around 2%. But, it is expected to rise with the increase in the number of farm fires. However, the dip in air quality will be determined by weather conditions such as wind speed and upper wind direction. As per the forecast, AQI is likely to deteriorate from October 13 and may fall into ‘very poor’ category,” a Safar statement said.

AQI in the range of 0-50 is considered ‘good’, 51-100 ‘satisfactory’, 101-200 ‘moderate’, 201-300 ‘poor’, 301-400 ‘very poor’ and 401-500 ‘severe’.

Meanwhile, Delhi chief minister Arvind Kejriwal on Friday said the smoke from burning of crop stubble in neighbouring states was causing a spike in pollution levels in Delhi and hoped that all agencies and institutions, including Punjab and Haryana governments, the Supreme Court and the National Green Tribunal (NGT), will take concrete steps to counter the problem.

“Pollution in the city reduced 25% in the earlier part of the year. But the burning of stubble in neighbouring states in October and November is resulting in ‘severe’ pollution. The smoke has started affecting Delhi’s air quality. We have been taking every possible step to curb the bad air,” Kejriwal tweeted.

The Delhi Pollution Control Committee (DPCC) too has issued directions for ban on diesel generator (GD) sets in the city under the Graded Response Action Plan (Grap), which will come into effect on October 15.

“We have directed the concerned agencies to ensure a ban on use of diesel generator sets run on diesel, petrol or kerosene, with effect from October 15. The ban will continue up to March 15, 2020 or till further orders,” stated the note issued by the DPCC.

The Supreme Court-mandated Environment Pollution (Prevention and Control) Authority had also predicted a rise in the pollution levels in the city from October 12, and ordered that Grap — a set of emergency measures to combat ‘very poor’ and ‘severe’ levels of pollution — come into force from October 15.

According to data from the United States’s National Aeronautics and Space Administration (Nasa), the number of fires spotted in Haryana and Punjab recorded a significant spike over the last two days.

Weather officials said the immediate change in air quality is due to climatic conditions typical of a post-monsoon, pre-winter period. As the monsoon withdraws, an anti-cyclone wind pattern has formed over Rajasthan, which results in stagnant weather conditions such as low wind speed that does not allow pollutants to disperse.