The air quality in Delhi and its surrounding areas improved marginally on Tuesday, after several days of severe pollution.

According to the government-run monitoring agency System of Air Quality and Weather Forecasting and Research, or SAFAR, the overall air quality index in Delhi as of 10.30 am was recorded at 378, which falls in the “very poor” category. The 24-hour average calculated by the Central Pollution Control Board was 365 as of 9 am. The CPCB index is typically lower than that of SAFAR because it averages values for 24 hours, and caps hourly indices at 500 even if they are of a higher value.

SAFAR measures the air quality in real time, based on index values that are recorded at up to nine stations spread across the city and one each in Noida and Gurugram. An AQI between 0 and 50 is considered as “good”, 51-100 is “satisfactory”, 101-200 “moderate”, 201-300 “poor”, 301-400 “very poor” and 401-500 “severe”. A figure above 400 poses a risk for people with respiratory ailments and can affect even those with healthy lungs.

Air pollution in Delhi and surrounding towns plummeted to the season’s worst level on Sunday. On Friday, authorities had declared a public health emergency, and closed schools and banned all construction activities till November 5. Tuesday is the second day of the Delhi government’s odd-even scheme, one of its attempts to reduce pollution.

Scientists from the India Meteorological Department attributed the better air to an increase in wind speed on Monday, according to the Hindustan Times.

“It was after long, maybe after Diwali day, that the sky was clear, with sunlight being able to penetrate to the ground,” IMD scientist Kuldeep Srivastava told the newspaper. “On Monday, the winds also picked up pace, helping pollution levels to improve. Though in ‘severe’ zone, the toxicity in the air reduced by noon. It is expected to get better on November 5.”

He added: “Air quality may dip again due to cloud formation and rainfall is likely on November 6, but pollution levels will most likely dissipate by the evening.”

On Monday, the National Green Tribunal had blamed continuous negligence by authorities for the high pollution in Delhi and said there was an urgent need to address gaps in existing enforcement strategies.

Earlier in the day, the Supreme Court had criticised the state governments of Delhi, Haryana, Punjab and Uttar Pradesh, and the Centre for the pollution in the national Capital. It ordered an immediate halt to stubble burning in Punjab and Haryana, and asked the Delhi government to prove that its odd-even scheme for vehicles had reduced pollution. The court also ordered all construction activities in Delhi and the National Capital Region to be stopped.

The amicus curiae (friend of the court to assist it in the matter) had told the top court that as per the Centre’s affidavit, crop burning was up by 7% in Punjab and down by 17% in Haryana.

Haryana Chief Minister Manohar Lal Khattar echoed this statement on Monday, according to PTI. “In the last 24 hours, only 70 cases of burning of agriculture residue has been reported in Haryana which is much lower than the cases reported in the neighboring state of Punjab,” he said.

But urging the affected states to make joint efforts to address the problem, he added: “The states should refrain from playing the blame game on the issue of air pollution as the problem is not confined to a particular state.”

Now, follow and debate the day’s most significant stories on Scroll Exchange.