Table 1.
WHO-recommended AQG levels and interim targets.
| Pollutant | Averaging Time | Interim Target | AQG Level | |||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | |||
| PM2.5, μg/m3 | Annual | 35 | 25 | 15 | 10 | 5 |
| 24 h a | 75 | 50 | 37.5 | 25 | 15 | |
| PM10, μg/m3 | Annual | 70 | 50 | 30 | 20 | 15 |
| 24 h a | 150 | 100 | 75 | 50 | 45 | |
| O3, μg/m3 | Peak season b | 100 | 70 | - | - | 60 |
| 8 h a | 160 | 120 | - | - | 100 | |
| NO2, μg/m3 | Annual | 40 | 30 | 20 | - | 10 |
| 24 h a | 120 | 50 | - | - | 25 | |
| SO2, μg/m3 | 24 h a | 125 | 50 | - | - | 40 |
| CO, mg/m3 | 24 h a | 7 | - | - | - | 4 |
a 99th percentile (i.e., 3–4 exceedance days per year). b Average of daily maximum 8 h mean O3 concentration in the six consecutive months with the highest six-month running-average O3 concentration. Source: https://cdn.who.int/media/images/default-source/air-pollution/recommended-aqg-levels-and-interim-targets.jpg?sfvrsn=9f9136ef_2, accessed on 15 August 2023.