Air quality dashboard reveals shift in Delhi's pollution pattern: rising Ozone, declining NO2 and CO
A new air quality dashboard by Envirocatalysts, based on CPCB data since 2015, highlights a significant shift in Delhi's pollution trends. While fine particulate matter (PM2.5) and coarse particles (PM10) show winter peaks and overall decline since 2015, they remain above safety limits. Notably, nitrogen dioxide (NO2) and carbon monoxide (CO) emissions, linked to combustion sources, have shown a gradual decline. In contrast, ground-level ozone (O3) levels are rising, particularly in summer (May), due to photochemical reactions driven by strong sunlight, indicating an emerging seasonal risk and a broader regional shift beyond the Capital.
Key Points
- Delhi's air quality trends show a decline in PM2.5, PM10, NO2, and CO since 2015, though PM levels remain high.
- Ground-level ozone (O3) is increasing, especially in summer, due to photochemical reactions.
- Ozone peaks in May, with Delhi's annual average rising from 52 µg/m³ in 2021 to 66 µg/m³ in 2025.
- The dashboard indicates a broader regional shift, with Meerut, Noida, and Muzaffarnagar also showing steep increases in ozone.
- PM10 emerged as the dominant pollutant across NCR in April, with several surrounding cities recording worsening PM2.5 trends.
Exam Facts
- Data source: Central Pollution Control Board (CPCB)
- Research by: Envirocatalysts (Delhi-based think tank)
- Pollutants showing decline: PM2.5, PM10, NO2, CO
- Pollutant showing rise: Ozone (O3)
- Delhi's annual average ozone rise: 52 µg/m³ (2021) to 66 µg/m³ (2025)
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