Delhi-NCR’s Diwali was its most polluted in five years and, by official data, the fourth most polluted day of the year. But once again, it exposed gaps in pollution data and the government’s system to measure and publicise air toxicity.
What created concern among researchers, journalists and environment and public health activists was the missing AQI data, particularly levels of the most polluting PM2.5 and PM10 particles. Many Central Pollution Control Board monitoring stations did not even show these numbers for several hours while other platforms and Delhi Pollution Control Committee’s monitors recorded severe toxicity.
