PM2.5 and AQI : measuring air pollution
Since September 9th 2013, all countries are now using the same PM2.5 AQI conversion scale.
Here’s how you convert:
| AQI Category | AQI Index Values | PM2.5 Previous Breakpoints (µg/m3, 24-hour average) | PM2.5 Revised Breakpoints (µg/m3, 24-hour average) |
| Good | 0 – 50 | 0.0 – 15.0 | 0.0 – 12.0 |
| Moderate | 51 – 100 | >15.0 – 40 | 12.1 – 35.4 |
| Unhealthy for Sensitive Groups | 101 – 150 | >40 – 65 | 35.5 – 55.4 |
| Unhealthy | 151 – 200 | > 65 – 150 | 55.5 – 150.4 |
| Very Unhealthy | 201 – 300 | > 150 – 250 | 150.5 – 250.4 |
| Hazardous | 301 – 400 | > 250 – 350 | 250.5 – 350.4 |
| Hazardous | 401 – 500 | > 350 – 500 | 350.5 – 500 |
