New Delhi: Rashtriya Swayamsevak Sangh (RSS) chief Mohan Bhagwat has said that the firecrackers of earlier times were free of harmful chemicals and helped eliminate insects, even as Delhi experienced one of its most polluted Diwali days in a decade, with the national capital recording its fourth-highest daily average PM2.5 concentration of the year on November 8, according to an analysis conducted by Centre for Research on Energy and Clean Air (CREA). Addressing a Diwali gathering in Nagpur on Tuesday (November 10), Bhagwat said that lamps fuelled by ghee helped purify the atmosphere. “The firecrackers of earlier times were not made using chemical substances as they are today. Their smoke helped kill insects and pests, particularly around the harvest season, and in a way, purified the atmosphere,” he said. “When lamps fuelled by ghee or oil were lit, they created a particular kind of air in the environment. There was science behind these traditional practices,” he said, invoking the phrase Vatavaran shuddh, jeevan shuddh (a clean environment leads to a pure life), Press Trust of India (PTI) reported.He called for an environment-friendly Diwali and urged people to understand the purpose of traditional customs rather than follow them without knowing why. He described dharma as a force that unites society and said women often understand it more deeply than men.Delhi under ‘severe’ pollution a day after DiwaliThe Hindu reported that Delhi’s 24-hour average Air Quality Index (AQI) stood at 370 at 9 am on Monday (November 9), a day after Diwali, according to Central Pollution Control Board (CPCB) data. The city was therefore placed in the ‘very poor’ category. The Times of India reported that the capital’s average AQI on Diwali was 376, and PTI reported that it settled at 371 at 10 am on Monday, enveloping the city under a blanket of smog and fog. However, several localities, including Chandni Chowk, ITO, Rohini, Mundka and Delhi University’s North Campus, continued recording ‘severe’ air quality.Also read: Diwali Night Exposes What Delhi Breathes the Rest of the Year“99 out of 100 most polluted cities in the World are in India right now,” the official account of AQI India, a private air quality monitoring platform, said in a post on X.The peaks were far higher than the daily averages. Data from the Delhi Pollution Control Committee (DPCC), cited by TH, showed fine particulate matter (PM2.5) at 993 micrograms per cubic metre (µg/m³) at Punjabi Bagh at 4 am on Monday, about 66 times the World Health Organisation’s 24-hour guideline of 15 µg/m³. Vivek Vihar recorded 873 µg/m³ at 2 am, and R.K. Puram recorded 924 µg/m³ at 10 pm on Sunday.The Indian Institute of Tropical Meteorology (IITM) attributes about 71% of Delhi’s PM2.5 on the day after Diwali to firecrackers, in source apportionment data published online by the IITM’s Air Quality Warning and Integrated Decision Support System for Emissions (AIRWISE), firecrackers contributed about 71% of Delhi’s PM2.5 on November 9, as The Wire reported on Tuesday. Firecrackers contributed only 5.6% of PM2.5 levels in Delhi on November 5 and 43.4% on Diwali day (November 8). Vehicles, the next largest contributor on November 9, accounted for 6.9%. The firecracker share fell to 29.8% on November 10, a figure based only on readings from 1 am to 9 am.IITM scientist Sachin Ghude, who heads AIRWISE, told The Wire that this was the first time the institute had treated firecrackers as a separate source, because Diwali coincides with the historical peak of stubble burning. “It’s not good for health,” he said, adding that the lead and aluminium content was significantly high. Lead peaked at 20.788 µg/m³ at night, against a permissible limit of 1.0 µg/m³ over 24 hours under the National Ambient Air Quality Standards, though a short-term peak and a 24-hour limit are not strictly comparable.Residents burst crackers past the Supreme Court’s 10 pm deadline, and an analyst estimated that three-quarters of the extra pollution came after it.The Supreme Court had permitted only green firecrackers within specified time windows on November 7 and 8, but residents kept bursting crackers well beyond the 10 pm deadline, The Wire has reported. Sunil Dahiya, founder and lead analyst of EnviroCatalysts, wrote in an analysis for The Wire, based on provisional CPCB and DPCC data, that about three-quarters of the extra pollution arrived after the 10 pm deadline and that sulphur dioxide nearly quadrupled.Readings above 1,000 µg/m³ dropped out of the public feed just as the pollution peakedNDTV reported that the DPCC’s website stopped displaying real-time data from several stations, among them R.K. Puram, Nehru Nagar, Mundka, Sonia Vihar and Dwarka, as levels surged. A Hindustan Times analysis found that 42% of the expected hourly PM2.5 readings from 39 stations were missing between 10 pm and 6 am, while several stations kept reporting gaseous pollutants even as their particulate readings disappeared. NDTV noted that similar interruptions occurred last Diwali too, with technical glitches often cited as the reason.Dahiya found that by 1 am only 23 of 59 Delhi stations were still reporting on the CPCB feed, and that DPCC data for the same monitors showed they had not failed: every missing hour read above 1,000 µg/m³. Twenty-one stations recorded at least 900 µg/m³ before going quiet. The official citywide peak was 592 µg/m³, but adding back the DPCC readings, even capped at 1,000, raises it to about 730 µg/m³, he wrote. The DPCC later released the missing hours, which, The Wire reported, citing The New Indian Express, put Mundka at 3,744 µg/m³ and showed all 125 absent station-hours above 1,000 µg/m³.Also read: Firecrackers Contributed More Than 70% of Major Air Pollutant PM2.5 On Diwali in DelhiAam Aadmi Party (AAP) Delhi president Saurabh Bharadwaj alleged that the Bharatiya Janata Party (BJP) government in Delhi had deliberately shut down monitoring stations on Diwali night to conceal the real pollution levels, calling it “data fraud”. He also alleged that the government had added 20 stations in greener, cleaner areas to lower the city’s average. Dahiya noted separately that 19 new stations, added in less polluted areas this year, pull the average down, so a simple comparison with last year overstates any improvement. Diwali night is a visible spike on top of a pollution load Delhi carries all yearAt 4 pm on Diwali day, before a single cracker was burst, Delhi’s PM2.5 was already about 136 µg/m³, Dahiya wrote, more than twice the national 24-hour standard of 60 µg/m³ and about nine times the WHO guideline. On November 7, he noted, IITM’s real-time source apportionment put secondary aerosols at about a third of the city’s PM2.5, biomass burning at about a quarter, waste burning at 13% and vehicles at 10%. Firecrackers and stubble fires are episodes, he argued, while “the baseload is the problem”.Also read: Delhi’s Missing Diwali-Night Pollution Data Released: PM2.5 Crosses 3,700; Politicians Cling to SuperstitionWinter weather compounds this. Between 2018 and 2025, Delhi’s PM2.5 averaged 34-38 µg/m³ in July and August but 219 µg/m³ in November, Dahiya wrote, and on Diwali night the mixing layer was only 55-80 metres deep, with near-calm winds. His proposals for firecrackers include licensed manufacturing whose chemistry is independently tested, traceable sales and real penalties for bursting outside permitted hours.The data speak to this year’s crackers, not to those of earlier timesThe IITM analysis covers the festival of 2026. It does not compare today’s fireworks with those of earlier decades, and the accounts of Bhagwat’s speech reviewed for this report do not cite a study for the claims on chemicals, insects or ghee lamps. Bhagwat himself separated earlier firecrackers from those made with chemicals today.The Wire’s reporting on the IITM data noted that firecrackers traditionally comprise a mixture of black powder or gunpowder, which contains potassium nitrate, sulphur and charcoal, along with metal fuels such as aluminium, magnesium and titanium and colouring agents such as barium, strontium, copper and sodium. In low-wind conditions like Delhi’s winter, it added, these chemicals can persist in the atmosphere.