Delhi air on verge of severe; AQI at 398 as thick haze shrouds capital

New Delhi, Dec 20 (PTI) The sky remained shrouded in dull grey, while a thick haze descended upon the capital on Saturday, with the air quality on the brink of "severe".

At 4 pm, Delhi's 24-hour average Air Quality Index (AQI) was recorded at 398 -- just two points shy of the threshold -- while several monitoring stations across the city reported readings in the 'severe' category.

Meanwhile, hourly AQI readings from the CPCB's SAMEER app showed that air quality worsened during the evening hours, slipping into the severe category at 401, at 5 pm.

Of the 40 monitoring stations across the city, 22 recorded air quality in the severe range, while 17 logged readings in the 'very poor' category.

Chandni Chowk reported the worst air quality, with an AQI reading of 464, in the 'severe plus' category.

With the sun largely obscured by clouds and suspended pollutants, visibility was greatly reduced.

Amid prevailing cold-wave conditions, the average air quality in the capital deteriorated to 398 on Saturday, compared to 374 on Friday and 373 on Thursday, according to official data.

According to the Central Pollution Control Board (CPCB), an AQI between 0 and 50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor', and 401-500 'severe'.

According to data from the Decision Support System for Air Quality Management, vehicular emissions emerged as the largest contributor to air pollution, accounting for up to 17.5 per cent, while industries in and around Delhi-NCR contributed 8.9 per cent.

Residential sources accounted for 4.3 per cent pollutants, while 1.5 per cent stemmed from open biomass burning.

Among the NCR districts, Jhajjar recorded the highest contribution at 16.5 per cent, followed by Bhiwani at 4.2 per cent, Rohtak around 4.38 per cent and Gurugram at 2.1 per cent.

The air quality in Delhi is likely to remain in the severe category on Sunday and Monday before improving marginally to the very poor category on Tuesday, according to the Air Quality Early Warning System.

The forecast has been attributed to unfavourable meteorological conditions, with the ventilation index remaining below 6,000 square metres per second and average wind speeds below 10 km/hr, conditions not conducive to dispersion of pollutants.

Several parts of the capital was enveloped in dense smog during the early morning hours, leading to poor visibility, earlier forecast by the India Meteorological Department.

In view of the worsening air quality, a ban on the entry of non-Delhi private vehicles that do not meet BS-VI emission standards came into force in the capital on Thursday, as authorities stepped up measures to curb rising air pollution.

Enforcement of the 'No PUC, No Fuel' rule has also begun, with fuel stations barred from dispensing fuel to vehicles without valid Pollution Under Control (PUC) certificates, officials said.

The enforcement is being carried out using automatic number plate recognition (ANPR) cameras, voice alerts at fuel stations and police support, they added. PTI SGV NSM ARB ARB