Air Quality Tracker: Delhi National Capital Region

This report was published by the Centre for Science and Environment, a New Delhi based public interest research organisation, on August 6, 2024. It has been written by Avikal Somvanshi and Sharanjeet Kaur. The report presents a study of ground-level ozone in Delhi National Capital Region. Ground-level ozone is a short-lived and localised pollutant in urban areas that can lead to severe respiratory distress and impaired pulmonary function. Ozone is produced in the atmosphere when nitrogen oxides (NOx) and volatile organic compounds (VOCs) undergo complex photochemical reactions.Due to both public interest and policy being concentrated on reducing particulate pollution, there is limited monitoring and information for ozone, the report notes. It uses publicly available granular data from the Central Control Room for Air Quality Management – the official online portal of the Central Pollution Control Board (CPCB) – to analyse trends in 2020-2024 over the summer (1 April-18 July). This data is sourced in 58 official stations in Delhi-NCR. Given the high toxicity of ground-level ozone, the national ambient air quality standard has been set to 100 μg/m3 (microgram per cubic meter) for an exposure of eight hours on average.This 14-page document is divided into 3 sections: Overview (Section 1); Key highlights (Section 2) and Act Now (Section 3).