Air Quality Health Guide
PM2.5 Health Scale
0–12 µg/m³ — Good
Air quality is satisfactory. Little or no health risk.
12–35 µg/m³ — Moderate
Acceptable. Sensitive individuals should limit prolonged outdoor exertion.
35–55 µg/m³ — Unhealthy (Sensitive Groups)
People with respiratory conditions, elderly, and children should reduce outdoor exertion.
55–150 µg/m³ — Unhealthy
Everyone may experience health effects. Sensitive groups more seriously affected.
150–250 µg/m³ — Very Unhealthy
Health alert: everyone may experience serious health effects.
250+ µg/m³ — Hazardous
Emergency conditions. Everyone should avoid outdoor activity.
Common Pollutants
| Pollutant | Source | Health Effect |
|---|---|---|
| PM2.5 | Combustion, vehicles, industry | Deep lung penetration, cardiovascular effects |
| PM10 | Dust, pollen, construction | Airway irritation, worsens asthma |
| O3 | Sunlight + pollutants | Lung damage, worsens asthma |
| NO2 | Vehicles, power plants | Airway inflammation, infections |
| SO2 | Fossil fuel combustion | Bronchoconstriction, asthma attacks |
| CO | Incomplete combustion | Reduces oxygen delivery to organs |