The national Capital got the infamous tag of the most polluted city in the world on Saturday morning as smog enveloped the city on the eve of Diwali and reduced visibility, according to a list prepared by Swiss group IQAir’s live ranking.
The Air Quality Early Warning System for Delhi recorded the AQI (Air Quality Index) of 369, which was in the ‘very poor’ category on Saturday. The air quality is forecast to turn ‘severe’ on Sunday, with Diwali celebrations, vehicular emissions and the peak stubble-burning season expected to add to the pollution burden.
According to Swiss group IQAir’s live ranking, Delhi is first among the world’s major cities at 10:35 am (0505 GMT), with a US air quality index reading of 581, and double that of Lahore in neighbouring Pakistan, at 285. IQAir’s reading, based on concentrations of air pollutants, is not directly comparable to India’s official index, which uses a different scale and methodology. At the same time, Central Pollution Control Board (CPCB) put Delhi’s air quality index at 363 at 10 a.m., in the ‘very poor’ category.
The Delhi government said it will implement the ban on vehicles below BS-VI emission standards registered in other states or Union territories every year between November 1 and January 31. It earlier announced a ban on the plying of non-Delhi-registered motor vehicles that are below BS-VI emission norms for the same period this year — which is usually marked by the worst of the city’s air pollution and quality — under its Winter Action Plan to limit vehicular emissions and curb dust on roads. The Delhi Directorate of Education has also directed all government and private schools to conduct classes up to class 5 in hybrid mode in view of worsening air quality in the national Capital.
Of the 59 monitoring stations that recorded data on Saturday, air quality remained in the ‘severe’ category at 16, while at 29 stations it was in the ‘very poor’ category. The worst AQI was recorded near IIT Delhi at 452. The city’s average AQI improved slightly from 382 on Friday to 369 on Saturday, remaining close to the ‘severe’ threshold of 400. Several monitoring stations have already breached this mark, indicating deteriorating air quality across the Capital.
According to the Air Quality Early Warning System (EWS) for Delhi, the air quality is likely to remain in the ‘severe’ category on November 8 and 9. The outlook for the subsequent six days indicates that the air quality is likely to fluctuate between the ‘severe’ and ‘very poor’ categories.
Weather and air quality experts have attributed the anticipated deterioration to unfavourable meteorological conditions, the onset of Diwali-related celebrations and vehicular emissions, and the peak period of stubble burning in neighbouring States.
Unfavourable meteorological conditions are further aggravating the situation. According to the EWS, a ventilation index below 6,000 square metres per second, coupled with an average wind speed of less than 10 kilometres per hour, is unfavourable for the effective dispersion of pollutants. PM10 was the predominant pollutant in the national Capital on Saturday.
According to the Decision Support System (DSS) for Delhi, the transport sector was the largest contributor to the city’s pollution on Saturday, accounting for 21.4 per cent. The contribution of stubble burning was pegged at 1.7 per cent, with forecasts suggesting that it might go up to 5.4 per cent on Sunday.
Satellite data showed 589 residue-burning incidents across six states on Friday. Of these, 357 were reported in Punjab, nine in Haryana, 23 in Uttar Pradesh, 58 in Rajasthan, three in Uttarakhand and 139 in Madhya Pradesh. A total of 6,226 farm fire incidents have been detected across the six states between September 15 and November 6.
The Consortium for Research on Agroecosystem Monitoring and Modelling from Space (CREAMS) Laboratory of the Indian Agricultural Research Institute provided the data in its bulletin.