| 优或良 | 轻度污染 | 中度污染 | 重度污染 | |
| <0.5 mm | 49.0 | 33.9 | 11.0 | 6.1 |
| 0.5~5 mm | 82.2 | 15.5 | 1.6 | 0.8 |
| 5~10 mm | 84.2 | 12.1 | 3.7 | 0.0 |
| >10 mm | 90.7 | 9.3 | 0.0 | 0.0 |