New Delhi: Delhi’s PM10 levels surpassed India’s annual standard of 60 micrograms per cubic metre on April 9, nearly six months before the start of the winter season, according to Centre for Research on Energy and Analysis (CREA). The PM10 concentration touched 170 micrograms per cubic metre by Oct 17, 2.8 times the national standard.Among the five cities which were analysed, Delhi crossed the benchmark first for overshoot days, within the first four months of the year. Bengaluru crossed the benchmark in late Sept, followed by Kolkata in mid-Oct. Chennai and Mumbai were approaching the same threshold by mid-Oct, with Chennai expected to cross the annual PM10 standard by the end of Oct and Mumbai in the first week of Nov, if the current trends continue, as per CREA’s analysis.The overshoot date is the first date on which the cumulative sum of daily PM10 concentrations, divided by 365, reached India’s annual standard of 60 micrograms per cubic metre on April 9. “The date on which this value first reaches 60 micrograms per cubic metre is identified as the benchmark-crossing date. In other words, pollution up to that date is already sufficient to push the annual average to the national limit, even if concentrations were zero for the rest of the year,” said CREA.Past data show that Delhi has been generally crossing the national annual PM10 standard in April. The city surpassed its annual quota of 60 micrograms per cubic metre on April 12 in 2025, April 2 in 2024, April 8 in 2023 and April 5 in 2022. However, it reached 60 micrograms per cubic metre on March 18 in 2021, but it touched the annual standard on May 9 in Covid year 2020.“PM10 consists of inhalable particles with diameters of 10 micrometres or less. These particles can enter the respiratory system, and exposure is associated with adverse respiratory and cardiovascular effects. The health implications depend on factors including concentration, duration of exposure, particle composition and individual vulnerability,” said CREA.
