7 months ago
2
Following Deepavali, pollution successful Delhi inched adjacent to a five-year low with mean concentrations of particulate substance (PM) 2.5 crossed respective locations crossing 400 microgram per cubic metre (µg/m³) – levels not seen since 2021.
On Deepavali day, 9 cities retired of the 293 monitored by the Central Pollution Control Board (CPCB) reported an aerial prime scale (AQI) worth of supra 300, classed arsenic ‘very poor’ aerial quality. On the time aft Deepavali, Tuesday (for astir of the country), this roseate to 16 cities, according to information disposable connected the organisation’s website. Nearly each of these fell successful northbound India and successful the Indo-Gangetic plains. Nationally, Dharuhera successful Haryana reported the worst aerial prime scale speechmaking of 462 connected Tuesday (October 21, 2025).
Sharp spike
An investigation of PM 2.5 trends, which was recorded by CPCB’s automatic aerial prime sensors, by autarkic weather-and-climate agency, Climate Trends, showed a crisp spike successful particulate substance attraction from 4 p.m. connected Deepavali time (October 20) successful Delhi. From values of astir 150 astatine 4 p.m., it spiked to astir 650 by 11 p.m. This coincides with the play during which bursting firecrackers was legally permissible ( 8 p.m. to 10 p.m.) connected Deepavali day, per the reprieve by the Supreme Court.
The SC, successful its order, had allowed the usage of lone CSIR-validated ‘green crackers’, which reportedly exudes a minimum 30% little fume than their accepted counterparts. However, the sheer measurement of fireworks during the period, anecdotal reports of the unavailability of these firecrachers, and the aerial prime scale of the time pursuing Deepavali (Tuesday), suggest that these norms were violated.
A cardinal parameter that determines aerial prime levels are upwind speeds connected the festival nighttime arsenic good arsenic temperatures. When nighttime temperatures are low, fume and chemic pollutants hover similar haze and volition not emergence to higher reaches of the ambiance and get flushed out. Temperatures connected Deepavali nighttime this twelvemonth ranged from 23-25 grade C, the warmest successful 5 years but debased upwind speeds and the quantity of fume retarded its egress retired the Delhi and the Gangetic plain airshed.
“When examined together, PM 2.5 and somesthesia information uncover a accordant pattern: precocious emissions from fireworks and debased night-time temperatures jointly lend to elevated PM 2.5 concentrations. The crisp post-Deepavali spikes bespeak some sustained emissions and mediocre atmospheric dispersion,” the Climate Trends study notes.
“The Diwali of 2025 was 1 of the astir polluted successful caller years. The spike betwixt the nights of the 19th and 20th straight corresponds to the wide usage of firecrackers crossed Delhi-NCR. Moreover, visuals and crushed information corroborate that burning alleged ‘green’ crackers made nary measurable quality compared to regular ones. It’s present evident that allowing firecrackers during this clip of twelvemonth is simply not sustainable for the NCR region’s already captious aerial quality,” Palak Balyan, Research Lead, Climate Trends, said successful a statement.
A perusal of the AQI values connected Deepavali and the consequent time connected the CPCB website amusement that successful 2023, Delhi’s post-Deepavali (November 13) AQI was 358 (very poor) – adjacent to the 351 (very poor) reported astatine 4 p.m. this year. The five-year record, however, was connected November 5 successful 2021, erstwhile it recorded 462 (‘severe’). Deepavali AQI this twelvemonth successful the metropolis was 345, lone topped by Deepavali AQI of 382 connected November 4, 2021.
The CPCB presents an yearly study of aerial prime and noise-pollution levels nationally connected Deepavali nighttime and pursuing day. It is expected aboriginal this week. The Environment Ministry didn’t connection immoderate remark oregon investigation of the Delhi aerial prime connected Tuesday.
