Delhi crosses annual air quality standards for PM10, PM25 months before year-end

New Delhi: Delhi crossed the annual national ambient air quality standard (NAAQS) for PM10 of 60 micrograms per cubic metre for the entire year on April 12. Similarly, World Health Organization's annual safe limit of 15 micrograms per cubic metre was surpassed on Jan 20, shows a new analysis by thinktank Envirocatalysts.
After crossing the national and WHO's annual limits in April and Jan, respectively, if Delhi records even 0.1 micrograms per cubic metre daily for the rest of the year, the concentration will be higher.
The overshoot day is defined as a day when the average pollution levels preceding that day are so high that even a 0.1 micrograms per cubic metre daily concentration of the pollutant for the remaining days of the year would ensure the non-compliance of the city to the prescribed annual standard or guideline.
The analysis stated that the city crossed WHO's annual safe guideline for PM2.5 of 5 micrograms per cubic metre on Jan 7, and was likely to cross the national ambient air quality standard for PM2.5 of 40 micrograms per cubic metre in May.
The latest analysis of pollution for the past seven years (2019-25) shows that Delhi crossed the annual NAAQS in the first four to five months every year, before the arrival of the winter season when the city witnesses hazardous levels of pollution.
According to the analysis, the annual national limit of PM10 was crossed on April 2 in 2024, April 8 in 2023, April 5 in 2022, March 21 in 2021, May 9 in 2020 and April 1 in 2019. Similarly, the WHO's annual safe guideline for PM10 was breached on Jan 17 in 2024 and 2023.
Sunil Dahiya, founder and lead analyst at Envirocatalysts, said Delhi breaching both India's relaxed annual PM10 standard by April and WHO's stricter limit by Jan was a dire warning for public health.
"The early arrival of the annual air pollution ‘overshoot day' indicates insufficient progress in cutting emissions at source across Delhi and its airshed. While the transport sector measures like BS-VI norms and phasing out polluting two-wheelers help, we urgently need systematic, time-bound emission load reduction plans for all pollution sources with strict city-level and regional targets," said Dahiya.