Table 2 Grade standards for atmospheric environmental quality indicators: a representation of pollutant concentration limits across diverse air quality levels.
From: Air quality assessment in Beijing based on cloud model
Level | AQI | CO \((\mathrm{mg/m}^{3}\)) | NO\(_{2} ({\upmu }\mathrm{g/m}^{3}\)) | O\(_3 ({\upmu }\mathrm{g/m}^{3}\)) | \(PM_{10} ({\upmu }\mathrm{g/m}^{3}\)) | \(PM_{2.5} ({\upmu }\mathrm{g/m}^{3}\)) | SO\(_{2} ({\upmu }\mathrm{g/m}^{3}\)) |
|---|---|---|---|---|---|---|---|
Excellent | 50 | 2 | 40 | 100 | 50 | 35 | 50 |
Good | 100 | 4 | 80 | 160 | 150 | 75 | 150 |
Mild pollution | 150 | 14 | 180 | 215 | 250 | 115 | 475 |
Moderate pollution | 200 | 24 | 280 | 265 | 350 | 150 | 800 |
Severe pollution | 300 | 36 | 565 | 800 | 420 | 250 | 1600 |
