The air quality in Delhi worsened on Monday morning after Diwali celebrations as the index reading touched the 463 mark at 10 am, which falls in the “severe” category. The real-time air quality index, given by the Centre-run System of Air Quality and Weather Forecasting and Research, or SAFAR, was better than the reading recorded on the day after Diwali in recent years.

On November 8, 2018, the index had crossed the 600-mark. The post-Diwali air quality index was 367 in 2017 and 425 in 2016.

According to SAFAR, the airport area in Delhi recorded an air quality index value of 460 at 10 am, Pusa area was at 480, Aya Nagar at 477 and the IIT locality at 483. Noida recorded an air quality index of 668, while Gurugram’s was 379. A thick, toxic haze enveloped the national Capital and neighbouring cities.

However, according to the National Air Quality Index, given by the Central Pollution Control Board, the overall air quality in Delhi was still at 345 at 9 am because it gives a 24-hour average. It is also likely to deteriorate further as it captures more parts of Monday in the 24-hour period. This index was at 361 for Ghaziabad and 368 for Noida at 10 am.

SAFAR measures Delhi’s air quality based on index values recorded at up to nine stations spread across the city and one each in Noida and Gurugram. An air quality index reading between 301 and 400 is said to be “very poor”, while even worse air quality – 401 and beyond – is classified as “severe”. CPCB’s reading is based on up to 37 measuring stations in Delhi.

Very poor air quality poses a risk of respiratory illness on prolonged exposure, and severe levels can affect even healthy people and can have serious impact on those with existing diseases, according to the Central Pollution Control Board.

The national Capital sees a massive rise in pollution levels during this time of the year, which makes the air in the region extremely toxic. The phenomenon is blamed on the burning of crop stubble by farmers in Punjab and Haryana, as well as construction activity and Diwali festivities during a season with low wind speeds, which prevent pollutants from settling down.

Delhi’s air quality slipped to the “poor” category for the first time this season on October 10.

The Supreme Court last year allowed the use of only “safe and green firecrackers” for a maximum of two hours on Diwali to check pollution levels after the festival. But authorities have failed to enforce the rule as violations were reported from many areas, PTI reported. Over 200 fire-related incidents were also reported in Delhi on Diwali.

On Saturday, the Delhi government launched laser light shows to discourage residents from bursting firecrackers and to encourage them to celebrate Diwali with lights and music.

Mumbai air quality in safe levels

According to the SAFAR, the overall air quality index in Mumbai is 76, which falls the satisfactory category. “Cyclone Kyarr has managed to keep air pollution levels to its lowest for the west coast, and of the four cities where SAFAR records air quality, Pune followed by Mumbai were the cleanest, while ‘moderate’ pollution was witnessed in Ahmedabad, and ‘very poor’ levels in Delhi during Diwali,” said Gufran Beig, project director of SAFAR told Hindustan Times on Sunday.

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