New Delhi: A data analysis report by think tank Envirocatalyst, released Tuesday and based on data from Jan 1 to June 20, found that ozone peaks sharply in the afternoon, driven by solar radiation and photochemical reactions. However, PM2.5 remains high overnight and peaks during the morning rush hour.The report stated that nitrogen dioxide averages dropped by 9.4 per cent to 44 micrograms per cubic metre (µg/m³) in 2026, from 48 µg/m³ the previous year, during the period from Jan 1 to June 20. “Ground-level ozone witnessed a 20 per cent decline, averaging 35 µg/m³ and breaching safety ceilings only 1.7 per cent of the time, localised predictably around highly sunny afternoon cycles at 4pm,” said the report.The baseline exposure to PM2.5 saw a minor 2.2 per cent reduction, dropping from a citywide average of 90 µg/m³ in 2025 to 88 µg/m³ in 2026. During this period, Delhi exceeded the National Ambient Air Quality Standards (NAAQS) limit of 60 µg/m³ on 58.2 per cent days in 20226 and 64.4 per cent in 2025.Jinitha Varghese, program manager, clean air, at EnviroCatalysts, said, “Over 99 per cent of calendar days thoroughly fail global health benchmarks; the capital’s air quality cannot be treated as an episodic winter emergency; it is a structural public health crisis.”
