Delhi on Wednesday witnessed a spike of 84 points in its air quality index, plunging it into the ‘severe’ category in just a day’s time.

The city’s AQI stood at 418 from Tuesday’s figure of 334.

Four places in the national capital recorded air quality under ‘severe plus’ zone at 5 pm on Wednesday, with AQI level above 450. These include Anand VIhar- 463, Jahangirpuri- 457, Ashok Vihar 455 and Wazirpur- 450.

According to the Central Pollution Control Board (CPCB), the primary pollutants in the city’s air consisted of PM 10 and PM 2.5 (particulate matter). PM10 means particulate matter of 10 micrometers or less in diameter, while PM 2.5 refers to particulate matter which is 2.5 micrometers or less in diameter.

The readings regarding AQI in Delhi were based on observations from 36 out of the total 39 air monitoring stations, the CPCB said.

Many people complained of breathing discomfort, especially outdoors, and in the areas with more vehicular movement.

Talking to the newspaper, many expressed that they did not venture out for morning walks or other outdoor activities upon witnessing thick layers of smog in the morning hours, while they also felt uneasy.

A man who ventured out for a morning run in the New Delhi area said that the visibility was much less and the smog was quite dense, which made him return home.

The Indian Institute of Tropical Meteorology (IITM) in its Air Quality and Weather Bulletin for Delhi on Wednesday mentioned that meteorological conditions are likely to remain extremely unfavourable for effective dispersion of pollutants.

According to the CPCB, AQI falling between 401- 500 points (severe) affects healthy people and seriously impacts those with existing diseases.

Pollution levels in the areas adjoining Delhi, like Noida, Ghaziabad and Gurugram were no less harmful, but were under the ‘very poor’ zone.

Talking of the anti- pollution measures, the second stage of Graded Response Action Plan (GRAP) of the Commission for Air Quality Management (CAQM) which entails a host of steps including mechanical sweeping, water sprinkling and restrictions is in force across Delhi along with its stage- I measures.

It is likely that the CAQM may invoke the next stage of GRAP, in case the national capital’s AQI remains to be in the severe zone.

Not only Delhi NCR, in fact several places across Punjab, Haryana and Uttar Pradesh are also reeling under poor and very poor air quality.

Chandigarh’s AQI on Wednesday was 372, Dehradun- 291, Mandi Gobindgarh- 322, Panipat- 370, Rohtak 303 and Sonipat 338.

According to the pollution monitoring agency, AQI up to 50 points is considered ‘good’, 51 to 100 is ‘satisfactory’, 101 to 200 ‘moderate’, 201 to 300 ‘poor’, 301 to 400 ‘very poor’, 401 to 450 is ‘severe’ and above 450 ‘severe plus’.