What Does the Air Quality Index (AQI) and PM 2.5 Actually Mean?
Ever looked at an air quality report and wondered, “What does AQI 152 mean…” Here’s a simple breakdown to help you understand the Air Quality Index and what it means for your health and daily choices.
What is AQI?
The Air Quality Index (AQI) is a number used by governments and health agencies to communicate how polluted the air currently is—or how polluted it’s expected to become.
Think of it like a weather report for the air you breathe.
AQI Levels Explained
| AQI Range | Level of Concern | Color Code | What It Means |
|---|---|---|---|
| 0–50 | Good | 🟢 Green | Air is clean and safe for everyone. |
| 51–100 | Moderate | 🟡 Yellow | Acceptable, but may affect very sensitive people. |
| 101–150 | Unhealthy for Sensitive Groups | 🟠 Orange | Older adults, children, and people with lung issues should limit outdoor exertion. |
| 151–200 | Unhealthy | 🔴 Red | Everyone may start to experience health effects. |
| 201–300 | Very Unhealthy | 🟣 Purple | Health alert—serious risk for sensitive groups. |
| 301–500 | Hazardous | 🟤 Maroon | Emergency conditions—everyone should stay indoors. |
Why AQI Matters
- Short-term exposure to poor air can cause coughing, throat irritation, and shortness of breath.
- Long-term exposure increases risks of asthma, heart disease, and even premature death.
- Children, seniors, and people with pre-existing health issues are especially vulnerable.
What You Can Do
- Check daily AQI reports before going out (use apps like AirVisual or AQICN).
- Limit outdoor activities when AQI is high, especially exercise.
- Use air purifiers indoors and keep windows closed on bad air days.
- Wear N95 masks in extreme conditions or in high-smog cities.