The nation’s air pollution monitors were overwhelmed this week by toxic smog so severe that concentrations exceeded their upper measurement limit, equivalent to 66 times the World Health Organization’s recommended daily maximum, regulators said.
The admission comes after opposition politicians accused authorities of deliberately allowing gaps in official readings for several hours overnight Sunday into Monday, just as pollution surged with a barrage of fireworks for Deepavali, the Hindu festival of lights.
New Delhi is one of the world’s most polluted capitals, where winter smog from vehicle emissions, farm fires and industry already chokes millions.
But the missing readings meant official data failed to capture the full extent of the pollution at its worst.
“The government which shuts down air quality monitoring stations on the night of Deepavali, the government that does data fraud, how will you trust such a government?” Aam Aadmi Party Delhi president Saurabh Bharadwaj said in a video posted on X.
The Central Pollution Control Board (CPCB) rejected accusations of deliberate under-reporting, saying the gaps reflected “differences in measurement of pollutant concentration” rather than an attempt to conceal pollution.
“The designed system of automated data validation treats hourly readings beyond the calibrated range as outside range, and such readings are not used in the computation,” the CPCB said in a statement late Tuesday.
“During extreme episodes, which are occasional like Deepavali firecracker bursting, this may appear as a data gap at the particular station concerned,” it added.
Particulate matter analysers, installed when the National Air Quality Index was introduced in 2015, were calibrated to measure concentrations of up to 1,000 microgrammes per cubic metre. — AFP
