| 质量级别 | Cu | Cd | Zn | Pb | Cr |
| 背景值 | 22.6 | 0.097 | 72.4 | 26.0 | 61.0 |
| 一级 | ≤35.00 | ≤0.20 | ≤100.00 | ≤35.00 | ≤90.00 |
| 二级 | ≤100.00 | ≤1.00 | ≤250.00 | ≤300.00 | ≤300.00 |
| 三级 | ≤400.00 | - | ≤500.00 | ≤500.00 | ≤400.00 |