The Delhi air, which has already been already hazardous, has worsened further on Friday sliding to the ‘severe’ category posing serious health hazard to the residents.

The Central Pollution Control Board (CPCB) data put the average Air Quality Index (AQI) in the national capital on Friday at 415, a jump of 25 points from yesterday. For the past five days, the city reeled under ‘very poor’ air with the AQI deteriorating with each passing day.

Notably, the AQI levels at 450 and above reading marks ‘severe plus’ category necessitating the Graded Response Action Plan’s (GRAP) stage-IV. The measures under the GRAP-IV were recently revoked by the Commission for Air Quality Management (CAQM) after a slight improvement witnessed in the pollution levels over a week ago.

In addition to PM 2.5, the micro pollutants, PM 10 was also among the primary pollutants in the city’s air, the CPCB said. PM 2.5 matter is capable of striking deep into the respiratory system, while PM 10 is also harmful as once inhaled, these can affect the heart and lungs.

The worst air quality in the city was recorded at Jahangirpuri with an AQI level of 468, followed by Bawana- 467, Wazirpur- 462, Nehru Nagar- 460 and Mundka 457.

The data on city’s air released on Friday evening was based on readings from 38 monitoring stations out of the total 40 of them across the city.

Meanwhile, the air quality in the cities adjoining Delhi, like Faridabad and Ghaziabad, also turned ‘severe’ while Gurugram, Noida and Greater Noida remained under the ‘very poor’ category.

The sky is expected to remain mainly clear during the day, becoming partly cloudy towards evening, according to a Met Department forecast. However, as per weather office forecast for November 27, it has mentioned a possibility of generally cloudy sky with light rain.

Talking of the likely change in weather, Delhi’s Environment Minister Gopal Rai has said after November 27 there would be light rain and wind speed would also increase.

According to experts, increase in wind speed and rain helps dispersion of the pollutants that settle at lower levels.