Haze enveloped Delhi and its suburbs on Tuesday, with the capital recording its air quality in the very poor category for the fourth day on the trot.
According to a numerical model-based system developed by the Indian Institute of Tropical Meteorology in Pune, vehicular emissions (11 percent to 15 percent) and stubble burning (seven percent to 15 percent) currently stand as the two major contributors to the city's very poor air quality.
It also shows that pollution sources in Gautam Buddha Nagar, Uttar Pradesh, are responsible for up to 14 percent of the air pollution in the capital.
The city's average AQI was recorded at 350 at 10 am, the highest this season so far. The 24-hour average AQI was 347 on Monday, 325 on Sunday, 304 on Saturday and 261 (poor) on Friday, 256 on Thursday, 243 on Wednesday and 220 on Tuesday.
Rohini (410) and Mundka (433) recorded their air quality in the severe zone (AQI above 400).
The AQI was 232 in neighbouring Ghaziabad, 313 in Faridabad, 233 in Gurugram, 313 in Noida and 356 in Greater Noida.
An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe.
The city's air quality deteriorated to the very poor category on Saturday due to slow wind speed at night and a dip in the temperatures.
The air quality is expected to remain very poor for a few more days, according to the Centre's Air Quality Early Warning System for Delhi.
The capital's air quality in October 2023 has been worse compared to the last two years and meteorologists attribute it to the lack of rainfall.
Delhi Environment Minister Gopal Rai has demanded that the Centre impose a strict ban on buses operating with poor-quality diesel in the National Capital Region (NCR) areas of Haryana, Uttar Pradesh and Rajasthan.
Starting November 1, only electric, CNG and BS VI-compliant diesel buses will be allowed to operate between Delhi and the cities and towns of Haryana, Uttar Pradesh and Rajasthan falling within the NCR, according to directions issued by the Centre's Commission for Air Quality Management (CAQM).
In an effort to reduce pollution levels, the Centre announced in April 2020 that all vehicles sold in India must comply with the Bharat Stage VI (BS-VI) emission standards.
The Bharat Stage emission standards set legal limits on the amount of air pollutants such as carbon monoxide and particulate matter that vehicles in India can emit. These standards focus on improving emission control, fuel efficiency and engine design.
As vehicle manufacturers provide vehicles that meet these new norms, oil companies supply fuel that adheres to the BS-VI standards, known as the world's cleanest fuel.
Unfavourable meteorological conditions and a cocktail of emissions from firecrackers and paddy-straw burning, in addition to local sources of pollution, push the Delhi-NCR's air quality to hazardous levels during winter.
According to an analysis conducted by the Delhi Pollution Control Committee (DPCC), the capital experiences peak pollution from November 1 to November 15, when the number of stubble-burning incidents in Punjab and Haryana go up.
The Commission for Air Quality Management, a statutory body responsible for formulation of strategies to reduce pollution in Delhi-NCR, Monday said the number of stubble-burning incidents in Punjab and Haryana since September 15 has reduced by around 56 per cent and 40 per cent, respectively, compared to the corresponding period last year.
In the period between September 15 and October 29, the cumulative number of farm fires in Delhi, Punjab, Haryana and NCR areas of Rajasthan and Uttar Pradesh has reduced from 13,964 in 2022 to 6,391 in 2023, it said.
In Punjab, there were 5,254 stubble burning incidents during this 45-day period this year, compared to 12,112 in 2022 and 9,001 in 2021. This represents a reduction of 56.6 per cent and 41.6 per cent, respectively.
Haryana reported 1,094 stubble burning cases during this 45-day period this year and it is significantly lower than the 1,813 in 2022 and 2,413 in 2021. This reflects a reduction of 39.7 per cent and 54.7 per cent, respectively.
The Punjab government is aiming to reduce farm fires by 50 per cent this winter season and eliminate stubble burning in six districts -- Hoshiarpur, Malerkotla, Pathankot, Rupnagar, SAS Nagar (Mohali) and SBS Nagar.
According to the state's action plan to curb paddy straw burning, about 31 lakh hectares of land in the state is under paddy cultivation. This is expected to generate around 16 million tonnes of paddy straw (non-basmati), which will be managed through in-situ and ex-situ methods.
Haryana estimates that about 14.82 lakh hectares of land in the state is under paddy cultivation. This is expected to generate over 7.3 million tonnes of paddy straw (non-basmati). The state will attempt near elimination of farm fires this year.
The Delhi government launched a 15-point action plan last month to mitigate air pollution during the winter season, with a strong emphasis on addressing dust pollution, vehicular emissions and open burning of garbage.
In keeping with the practice of the last three years, the Delhi government last month announced a comprehensive ban on the manufacture, storage, sale and use of firecrackers within the city.