Table 3 Ambient air quality standards for substances that may be utilized in solar radiation management
Substance | U.S Environmental Protection Agency | European Environmental Agency | World Health Organization | |||
|---|---|---|---|---|---|---|
|  | Limit (μg/m3) | Averaging period | Limit (μg/m3) | Averaging period | Limit (μg/m3) | Averaging period |
Sulfuric acid | - | - | - | - | - | - |
Sulfur dioxide | 196.5 | 1 h | 350 | 1 h | 20 | 24 h |
| Â | Â | Â | 125 | 24 h | 500 | 10 min |
Hydrogen sulfide | - | - | - | - | - | - |
Carbonyl sulfide | - | - | - | - | - | - |
Nanoparticles | - | - | - | - | - | - |
PM2.5 | 12 | 1 year | 25 | 1 year | 10 | 1 year |
| Â | 35 | 24 h | -- | -- | 25 | 24 h |