8.1 Air Quality
Air quality refers to the concentration of pollutants in the atmosphere. Poor air quality causes millions of premature deaths annually.
Major Pollutants
PM2.5/PM10
Particulate matter <2.5/10 μm. Penetrates lungs, causes respiratory disease.
O₃ (Ozone)
Secondary pollutant from NOx + VOCs + sunlight. Causes respiratory damage.
NO₂
From combustion. Precursor to ozone and particulates.
SO₂
From coal burning. Causes acid rain, respiratory issues.
Air Quality Index
| AQI | Level | PM2.5 (μg/m³) |
|---|---|---|
| 0-50 | Good | 0-12 |
| 51-100 | Moderate | 12-35 |
| 101-150 | Unhealthy (sensitive) | 35-55 |
| 151-200 | Unhealthy | 55-150 |
| >200 | Very Unhealthy/Hazardous | >150 |