Key highlights

• Official AQI logic: overall AQI follows the worst sub-index among pollutants. Prana
• “Prominent pollutant” becomes the headline driver on many winter days.
• Explaining this well prevents panic and prevents denial.

People often assume AQI is an average. The official method says otherwise.

CPCB’s AQI framework—spelled out in NCAP documentation—explains that AQI is built by calculating sub-indices for key pollutants, and then the worst sub-index determines the overall AQI. Prana That one sentence is the cleanest explanation of “prominent pollutant” you can give without dramatics: the pollutant doing the most damage to the index is often the one the public should notice first.

The AQI system covers eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, Pb), with sub-indices linked to health breakpoints. Prana If PM2.5 is spiking, it can dominate the sub-index stack and drag the overall AQI into a worse category—even if other pollutants are comparatively stable.

Why does that matter for writing in early 2026?
Because readers don’t just want a number; they want a cause. “Prominent pollutant” is the nearest honest bridge between the two. It doesn’t claim why PM2.5 rose. It simply states what is currently driving the AQI outcome.

A good explainer can do three things:

• clarify that AQI categories are not vibes; they’re defined bands (Good to Severe) with stated health impacts Prana
• explain that the worst pollutant drives the headline, which is why some days feel suddenly worse
• warn against over-reading: one pollutant dominating today doesn’t mean it dominates every week

In a winter like North India’s, the air story is often about particles, not poetry. “Prominent pollutant” is the official language that keeps the story factual.