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| Haze over Delhi after Diwali on 5 November 2013. File photograph. TargetAimShoot / Wikimedia Commons, CC BY-SA 3.0. |
Delhi residents reported breathing difficulties on Monday after Diwali fireworks worsened air pollution across the Indian capital, where traffic emissions, construction dust and smoke from agricultural burning already affect air quality.
Authorities deployed water-spraying vehicles as a dense haze settled over the city following Sunday’s celebrations. The deterioration renewed environmentalists’ criticism of a decision to permit certain fireworks despite unfavourable weather and concerns about enforcement.
In a report by Al Jazeera English, one resident described the physical discomfort caused by the polluted air.
“I'm facing a lot of difficulties in breathing. I feel suffocated.”
Delhi recorded an Air Quality Index of 370 at 9am on Monday, placing it in India’s very poor category, according to Central Pollution Control Board figures reported by Reuters. Several neighbourhoods registered readings above 400, which the Indian system classifies as severe.
Those classifications differ from the United States’ reporting system. The US Environmental Protection Agency’s AirNow service categorises index readings of 151–200 as unhealthy, 201–300 as very unhealthy, and 301 or higher as hazardous.
An interviewee in Al Jazeera’s report described a sharp increase in PM2.5 readings between the morning and night of the celebrations. PM2.5 refers to airborne particles measuring no more than 2.5 micrometres in diameter; an air quality index translates pollution measurements into categories intended to communicate health risks.
The World Health Organisation identifies fine-particle exposure as a cause of respiratory and cardiovascular disease, as well as cancers. Its assessment of outdoor air pollution stresses the importance of reducing emissions from transport, energy production, industry and other sources.
Fireworks added another source of emissions during Diwali, the Hindu festival of lights. Their use followed a temporary relaxation of restrictions that allowed certified green firecrackers during specified hours.
India’s Supreme Court permitted their use in Delhi and the surrounding National Capital Region between 6am and 7am, and between 8pm and 10pm, on 7 and 8 November, according to public broadcaster Akashvani.
The conditions prohibited fireworks within 300 metres of hospitals, nursing homes, designated health centres, old-age homes and notified silence zones. The court also barred firecrackers containing barium and products lacking the required green certification.
The order provided for the broader ban to resume on 9 November.
Environmentalists interviewed by Al Jazeera questioned whether authorities could enforce the exemption effectively. One critic said officials had allowed fireworks despite knowing that weather conditions would hinder pollution dispersal and that enforcement remained inadequate.
The concern extended beyond whether a product carried a lower-emission designation. Critics questioned the practical ability to control which fireworks people used and to contain the resulting pollution when atmospheric conditions were already unfavourable.
Delhi’s air pollution predates the festival. Vehicle exhaust, building activity and agricultural fires in neighbouring states contribute to a recurring problem that intensifies during the colder months.
A February assessment considered by India’s Commission for Air Quality Management identified PM2.5 as the principal pollutant influencing Delhi’s air quality index. The review drew on studies conducted between 2015 and 2025 and highlighted emissions within the city alongside pollution moving into it from the wider region.
The assessment identified transport, biomass burning, dust, industry and particles formed through reactions involving gaseous emissions among the main winter contributors. Its findings underline the range of sources involved in Delhi’s pollution, beyond the additional smoke produced during festival celebrations.
The city’s difficulties have attracted international attention for years. WHO data released in 2014 placed Delhi at the top of the cities covered for annual average PM2.5 pollution, a finding subsequently discussed in a World Bank analysis.
Earlier attempts to improve conditions have included restrictions on vehicle use and fireworks. Al Jazeera reported that pollution controls had brought improvements, but the city continued to experience episodes in which air quality deteriorated sharply.
Weather also affects how long those episodes persist. Low wind speeds and stagnant conditions limit the dispersal of emissions, allowing pollution from different sources to accumulate near the ground.
Authorities’ deployment of water-spraying trucks formed part of their immediate response to the latest haze. Al Jazeera’s report identified stronger winds as a factor that could help disperse the accumulated pollution.