The air quality of Delhi, Gurugram and Noida, which together comprise the National Capital Region, dropped to the “poor category” on Friday morning, data from the Central Pollution Control Board showed.

The Air Quality Index of Delhi was 374 on a scale of 500 at noon, while the index values for Gurugram and Noida were 308 and 215.

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 401 and 500 is considered “severe”. The index measures the concentration of pollutants finer than 2.5 microns in diameter that can reach deep into the lungs and cause diseases like cancer and cardiac problems.

While Noida and Delhi, along with Ghaziabad and Greater Noida were in the “red category”, Gurugram was in the orange zone. A red reading means the air is dangerous enough to cause “respiratory illness on prolonged exposure”, according to the CPCB. Orange signifies that most people may face breathing discomfort due to prolonged exposure.

Meanwhile, ten of 35 monitoring stations across Delhi recorded air quality slipping into the “severe” category on Friday, showed data from the AQI monitoring mobile application SAMEER, developed by the Central Pollution Control Board, reported PTI.

These includes Alipur, Shadipur, Patparganj, Vivek Vihar, Anand Vihar, Jahangirpuri, Rohini, Wazirpur, Bawana and Mundka with an AQI above 400.

Nine of these stations are located at pollution hotspots, which have been identified by the government for the employment of intensive pollution control measures, according to the Hindustan Times.

Air quality expected to worsen

Government-run monitoring agency System of Air Quality and Weather Forecasting and Research, or SAFAR, said the air quality is expected to further deteriorate in Delhi over the next two days. This is because extremely calm surface wind conditions prevailing over Delhi, which are expected to continue over the next two days, will lead to low ventilation conditions for an extended period and accumulation of pollutants near the surface, it said.

“It is forecasted that the air quality will be in the higher end of ‘very poor’ on 24th and 25th October and may touch the ‘severe’ category,” SAFAR said. The agency added that a significant increase in stubble fire count was observed around Haryana, Punjab and neighbouring regions.

However, as the boundary layer wind direction is not fully favourable for pollutant transport towards the Delhi region, the SAFAR model estimate of stubble burning share in PM 2.5 is 17% for Friday, it said.

Commuters drive along a road under smog conditions in New Delhi on October 22. [Credit: Prakash Singh/ AFP]

The India Meteorological Department too predicted the air quality will worsen with pollutants PM 10 – the presence of particles with a diameter less than 10 micrometres – and PM 2.5 increasing.

“Air quality will deteriorate in the coming two days till October 24,” Anand Sharma, additional director general of IMD, told PTI on Thursday. “There are factors other than farm fires which are worsening the air like vehicular pollution, waste burning. PM 2.5 will increase and PM 10 which is now in ‘poor’ category will fall to ‘very poor’ by October 24.”

SC doing their part, state government must do theirs: Delhi HC

Meanwhile, the Delhi High Court on Thursday said the Supreme Court is already doing its part to deal with stubble burning in the neighbouring states of Punjab and Haryana. It said the Centre and state governments also have to do their bit to tackle the pollution.

The court made this observation while declining to entertain a plea seeking immediate steps to prevent stubble burning in Punjab and Haryana, on the grounds that it would aggravate coronavirus related problems.

A bench of Chief Justice DN Patel and Justice Prateek Jalan noted that the top court has already constituted a committee headed by its former judge, Justice MB Lokur, to monitor the steps taken by these states to prevent stubble burning. It said that if the High Court continues to hear the matter, then there would be a danger of contradictory orders being passed.

An annual affair

Delhi’s air pollution typically worsens during the winter months from October to December. The AQI was in the “poor category” for six consecutive days after it began to decline on October 7 for the first time in over three months. It deteriorated to the “very poor” category for the first time this season on October 13.

The Environment Pollution (Prevention and Control) Authority on Monday asked the Uttar Pradesh and Haryana governments to be ready to shut down thermal power plants that do not meet requirements laid down in 2015. On the same day, Delhi Chief Minister Arvind Kejriwal urged Union Environment Minister Prakash Javadekar to hold monthly meetings on pollution with the chief ministers of Delhi, Uttar Pradesh, Haryana and Punjab.

The Delhi Pollution Control Committee had last week banned the use of electricity generator sets of all capacities – whether running on diesel, petrol or kerosene – in order to curb the pollution. The committee had also declared the whole of the Union Territory of Delhi as an Air Pollution Control Area. It said Delhi faced grave air pollution during winters, and the levels of pollutants like PM 2.5 and PM 10 cross the prescribed standards for ambient air quality. The committee added that the operation of electricity generator sets running on petrol, diesel and kerosene had been identified as one of the sources of air pollution in the Capital.