India, Nov. 11 -- Most of the missing air quality data from Delhi Pollution Control Committee (DPCC) monitoring stations on Diwali night was updated, revealing alarmingly high particulate matter concentrations in the early hours of Monday, with readings at some locations soaring several times above prescribed limits.

However, gaps in the official pollution data persisted, with some particulate matter readings still unavailable and data from Central Pollution Control Board (CPCB) monitoring stations remaining missing, raising concerns over the completeness and reliability of the air quality records, experts said.

At RK Puram, for instance, PM2.5 levels surged to 2,389 micrograms per cubic metre at midnight, nearly 40 times the prescribed...