Delhi releases Diwali data showing PM2.5 peak of 3,744

Delhi’s pollution monitoring system recorded extreme PM2.5 levels during Diwali night, including a peak of 3,744 micrograms per cubic metre at Mundka, while dozens of stations lacked readings during the overnight pollution surge. The Delhi Pollution Control Committee released the missing station data on Monday, November 9, after gaps in Central Pollution Control Board records drew political accusations of deliberate suppression.

The committee’s figures showed that 11 monitoring stations recorded PM2.5 concentrations above 2,000 micrograms per cubic metre. Mundka registered the highest reading at 2 a.m.; Jawaharlal Nehru University recorded 3,023 at 4 a.m., and NSUT West Campus recorded 3,008 at 5 a.m. The Mundka peak was more than 60 times India’s national 24-hour standard of 60 micrograms per cubic metre.

The released data also showed that all 125 station-hour readings absent from the Central Pollution Control Board’s records exceeded 1,000 micrograms per cubic metre. That is the calibrated upper limit for the monitors, according to the board. Readings above that threshold are excluded from calculations under its automated validation system, the regulator said, and may appear...