Inside Chennai’s AQI: Why hyperlocal monitoring of air quality is crucial

by April 30, 2026 Environment
Official data masks Chennai's toxic air. Citizen Matters travelled with the IITM team to map variations in air quality. Watch the video to know more.

Across cities, official Air Quality Index (AQI) readings often overlook local hotspots. Chennai has eight Continuous Ambient Air Quality Monitoring Stations (CAAQMS) that function 24/7 throughout the year. But this isn’t enough to map particulate matter. Air changes every few metres, as researchers from the Indian Institute of Technology-Madras tell us. Seasonal variation, construction, vehicular movement, and proximity to industries also change the air we breathe,

In 2022, over 17 lakh people died in India due to air pollution (PM 2.5), according to a Lancet study. With better hyper-local air data and public awareness, citizens and policymakers can target pollution sources more effectively

Across Koyambedu and Ambattur Industrial Estate, IITM researchers found spikes and variations in PM2.5 and PM10. Citizen Matters travelled with the IITM team to map hyperlocal air quality near the Madras High Court and Parry’s Corner. Data and residents highlight the need for better monitoring to tailor better policies. 

Watch this video below to know more:

[Videography assistance provided by Garima S, digital storyteller at Oorvani.]

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About Archita Raghu

Archita Raghu is a Senior Reporter at Citizen Matters. She is interested in cities, gender, climate and policy. Archita has previously worked with The New Indian Express and BehanBox.
Read more by Archita Raghu

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