New Delhi's air quality was very poor for the second day, with an air quality index (AQI) reading of 327 on Tuesday, and is likely to remain in the ‘very poor’ to ‘poor' category for the next six days, according to the Centre's System of Air Quality and Weather Forecasting and Research (SAFAR).
The national capital's AQI reading was 310 on Monday. According to the Central Pollution Control Board (CPCB), the AQI is categorized into six groups: good (0-50), satisfactory (51-100), moderate (101-200), poor (201-300), very poor (301-400), and severe (401-500).
Due to low wind speeds every winter, toxic smog—the noxious mix of vehicular pollution, construction dust, and smoke from stubble burning—blankets the national capital. It's worsened by the bursting of firecrackers during the festive season leading up to Diwali.
Following the rising pollution levels, an 11-point action plan, as per Stage II of the Graded Response Action Plan (GRAP), was put into force on Monday.
GRAP is a set of emergency measures to control air pollution, implemented stage-wise by the Commission for Air Quality Management (CAQM) in the national capital region.
In Stage II, agencies, among other steps, carry out mechanical/vacuum sweeping, water sprinkling, and strict enforcement of dust control measures.
As a preventative measure, the Delhi Pollution Control Committee has completely banned the manufacturing, storage, sale, and use of all types of firecrackers in the national capital until 1 January.
Authorities in Punjab have also banned firecrackers. In Haryana's Gurugram, green crackers are allowed during Diwali celebrations.
The CSIR-National Environmental Engineering Research Institute defines green crackers as firecrackers made with a reduced shell size, without ash, and/or with additives such as dust suppressants to reduce emissions with specific reference to particulate matter. These crackers come without barium compounds, a metal oxide that contributes to air and noise pollution and gives them a green colour.
CREAMS-Indian Agricultural Research Institute, which monitors satellite data on crop residue burning, said in its Tuesday bulletin that stubble burning cases or fire incidents fell to 3,651 in neighbouring states like Punjab, Haryana, Uttar Pradesh, Rajasthan, and Madhya Pradesh between 15 September and 21 October, compared to 4,026 cases a year ago.
Smoke from post-harvest waste burning causes a surge in respiratory illness. People also experience burning eyes, heart ailments, sore throats, and skin allergies, among other health problems.
A recent report by Climate Trends, a research-based consulting and capacity-building initiative, said that air quality trends in Agra, Delhi, Faridabad, Ghaziabad, and Gurugram reveal a general decline from September to December each year between 2019 and 2023.
According to the report that analysed satellite data on fire incidents in Punjab and Haryana and its impact on Delhi’s air health, between 2019 and 2023, both Haryana and Punjab experienced fluctuations in fire incidents, with notable reductions in 2022 and 2023.
Haryana's fire counts dropped from 14,122 in 2019 to 7,959 in 2023, with fire activity consistently higher from September to December, though the last four months saw a 48% reduction over five years. Punjab followed a similar trend, with fires peaking at 95,048 in 2020 and decreasing to 52,722 in 2023, but the post-monsoon period remains the most fire-prone.
The report said that the fire incidents in Punjab and Haryana contributed to a 103-unit increase in Delhi's AQI, underscoring the urgent need for coordinated fire management and air quality interventions across states.
