On Tuesday morning citizens of the planet's dirtiest urban center encountered exposed to severely hazardous air that was classified as the "severe" category.
Various sections of the city showed an air quality index over 500, which translates to a tenfold increase over the healthy limit set by the WHO.
In some locations, levels of PM2.5 and PM10 reached peaks of eighteen hundred, amounting to 15-20x exceeding acceptable limits.
Beginning in 2020, the government had maintained a total prohibition on the purchase and ignition of fireworks during celebrations due to their significant contribution to the deadly pollution that engulfs the capital as winter approaches.
However in recent months, the recently formed city leadership appealed to the highest court to request a easing of the ban.
They proposed allowing "eco-friendly fireworks" – previously questioned by conservation groups as being only about 30% lower impact – as a balance between "tradition and environment".
To the disappointment of environmental and health campaigners, the court agreed to the proposal, stipulating that environmentally conscious fireworks could be set off during limited periods throughout the festival.
During the celebrations, there was considerable disregard of the time restrictions across the capital, with insufficient monitoring regarding whether the firecrackers being used were actually the eco-friendly version.
Numerous recording stations throughout Delhi showed contamination reaching highest levels around late evening to the most severe levels recorded during Diwali in at least recent memory.
The widespread use of fireworks during the celebrations also triggered a blame game with neighbouring Pakistan, with authorities in Pakistan's Punjab province partly blaming worsening pollution levels in Lahore on contaminants coming from across the border following the events.
Alarmingly severe readings of pollution in the city have persisted as a serious problem for over a decade and a half, with the condition continuing to worsen.
During Diwali, the amount of toxic particulate matter in the atmosphere has been observed to shoot up to 70% higher the most severe records ever documented in Beijing, which was formerly viewed as the world's most polluted urban center.
The problem in the city is caused by a combination of different contributors including heavy vehicle emissions, construction debris, development work, rubbish burning and smoke from farm burning in adjacent states of Punjab and Haryana.
Throughout these areas, agricultural workers illegally burn crop residue to prepare for next season, producing toxic smog that then gets trapped over the capital as colder air arrives.
The economic and health consequences on the roughly thirty-three million residents residing in the capital region is enormous, according to numerous research.
The contaminated air leads to elevated rates of neurological, cardiovascular and respiratory disorders, and can potentially cause cancer.
The pollution is projected to be causing ten thousand untimely mortalities annually in Delhi.
