On Tuesday morning residents of this heavily contaminated metropolis were faced with inhaling dangerously toxic air that fell into the "severe" range.
Various sections of the capital recorded an air quality index exceeding 500, which equals a tenfold increase over the safe level recommended by the World Health Organization.
Particular areas, levels of toxic particulate matter hit highs of eighteen hundred, representing 15-20x higher than healthy standards.
For the past four years, the government had implemented a comprehensive restriction on the purchase and ignition of fireworks during the Festival of Lights due to their substantial impact to the hazardous smog that covers the city as colder weather begins.
Nevertheless recently, the newly elected local administration petitioned the highest court to seek a modification of the prohibition.
Officials advocated for allowing "environmentally conscious pyrotechnics" – which have been doubted by environmental experts as being only roughly 30 percent lower impact – as a balance between "tradition and public health".
Much to the frustration of public health and environmental campaigners, the court complied with the request, specifying that eco-friendly pyrotechnics could be used during specific hours throughout the festival.
During the celebrations, there was considerable disregard of the designated hours across the capital, with minimal enforcement regarding whether the fireworks being used were actually the eco-friendly type.
Numerous air quality sensors throughout the capital showed air quality peaking around the night hours to the most severe measurements observed during Diwali in at least the past three years.
Extensive ignition of firecrackers during the festival also sparked a controversy with adjacent Pakistan, with representatives in Pakistan's Punjab pointing to worsening atmospheric conditions in their urban centers on pollutants coming from neighboring India following the events.
Extremely elevated readings of pollution in the city have remained as a serious problem for more than 15 years, with the problem continuing to worsen.
Around Diwali, the concentration of dangerous airborne contaminants in the air has been observed to spike to seventy percent above the most severe readings ever measured in Beijing, which was formerly considered as the world's most polluted city.
The situation in the capital is caused by a combination of multiple factors including heavy vehicle emissions, airborne particles, construction activities, waste incineration and pollutants from crop residue ignition in neighbouring areas of neighboring agricultural zones.
Within these states, farmers regularly set their fields on fire to prepare for next season, producing hazardous pollution that remains stagnant over the city as colder air sets in.
The economic and health impact on the approximately 33 million people residing in the metropolitan zone is enormous, according to multiple research.
These hazardous conditions causes high levels of neurological, heart and circulatory and breathing disorders, and can even lead to oncological diseases.
Air quality crisis is estimated to be causing 10,000 premature fatalities per year in the city.