The city of Rohtak in Haryana was the most polluted in the country on Sunday, with an air quality index of 498 at 4 pm, as computed by the Central Pollution Control Board. Delhi’s air quality index at the same time was 494, the worst in three years. The last time Delhi’s air was worse was on November 6, 2016, when the index reached the 497 level, PTI reported.

Many other cities in northern India had “severe” air quality on Sunday. Faridabad had an index value of 496, Noida was at 495, Ghaziabad and Jind were at 491, Gurugram at 486, Greater Noida at 482 and Hapur at 471. The Delhi government had on Friday announced a public health emergency. Schools in the national capital and nearby cities have been ordered shut till Tuesday.

An AQI between 0 and 50 is considered “good”, 51-100 is “satisfactory”, 101-200 “moderate”, 201-300 “poor”, 301-400 “very poor” and 401-500 “severe”. Anything above 400 poses a risk for people with respiratory illnesses and can affect even those with healthy lungs.

The situation in Delhi appeared to improve slightly on Monday, as the haze cleared a bit, even though the air quality remained severe. At 11 am, the overall 24-hour average air quality index in the city was 436, according to CPCB. Another index, calculated by the government-run SAFAR, put the figure at 588, which is in the severe-plus category. This was also better than Sunday noon’s figure of 625.

The CPCB’s index is typically lower than that of SAFAR because it averages values for 24 hours, and also because it caps hourly indices at 500 if they are of a mathematically higher value.

Anand Vihar locality in East Delhi, usually one of the worst-hit areas in the city, was at an air quality index of 468 at 11 am after PM2.5 levels improved to “very poor” category for a brief period around midnight.

On Sunday, PK Mishra, the principal secretary to Prime Minister Narendra Modi, had discussed the air pollution in the National Capital Region at a high-level meeting with officials from Punjab, Haryana and Delhi. After the meeting, it was decided that Cabinet Secretary Rajiv Gauba will monitor the situation in these states on a daily basis.

The burning of crop stubble in Punjab and Haryana is said to be a major reason behind the toxic air quality in the city in the early winter.

Also read:

  1. In photos: Delhi struggles to breathe as air pollution hits year’s worst levels
  2. Centre, Arvind Kejriwal continue blame game as Delhi smog thickens on Sunday
  3. Eat carrots, perform yagnas: What top ministers said on a day air pollution peaked in North India

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