The atmospheric pollution plaguing the Indian capital New Delhi is so concentrated that it has exceeded the capabilities of the sensors responsible for measuring it, the Government Pollution Control Bureau (CPCB) has admitted. Always high in the fall, the air concentration of PM2.5 microparticles, the most harmful, reached new heights on Monday after the night of the Hindu festivities of Diwali, where explosions of firecrackers and fireworks were in full swing.
It came close to 60 times the maximum daily threshold set by the World Health Organization (WHO). Opponents of Prime Minister Narendra Modi’s party, which heads the municipality/state of Delhi, have accused him of being at the origin of breakdowns in measurements observed overnight from Sunday to Monday, in order to hide the extent of the pollution.
“How can you trust a government that turns off air quality sensors on Diwali night, which commits such fraud?” Aam Aadmi Party (AAP) leader Saurabh Bharadwaj exclaimed on X. The CPCB responded to the controversy by denying any deliberate concealment of the data, explaining that the “holes” observed reflected “differences in the measurement of pollutant concentrations”.
The instruments installed in 2015 in Delhi are calibrated to record these concentrations up to 1,000 micrograms per cubic meter and not beyond, the Bureau explained on Tuesday. “During extreme episodes, including those linked to Diwali firecrackers, this can appear as a gap in the measurements,” according to CPCB, which added that the sensor concerned can only resume recording eight hours later.
3.8 million deaths in 10 years
The megacity of 30 million inhabitants regularly ranks at the top of the most polluted cities on the planet because of its automobile traffic, toxic emissions from the industries that surround it and, in the fall, agricultural burning. The initiatives of the Delhi authorities, whatever their political color, to limit pollution peaks have until now remained symbolic.
“There is one thing Delhi residents can be sure of, and that is that the gaps in the measurements do not mean that pollution has disappeared,” Congress MP Pawan Khera said of the controversy. “The poisoned air we breathe (…) continues to suffocate our lungs and reduce our life expectancy,” he added on social networks.
A study published in 2024 in the journal The Lancet estimated 3.8 million deaths in India linked to air pollution between 2009 and 2019.
