| Hg | As | Cd | Pb |
CK | 0.013 | 0.152 | 0.440 | 0.042 |
A | 0.156 | 0.465 | 0.124 | 0.036 |
B | 0.029 | 0.556 | 0.192 | 0.034 |
C | 0.056 | 0.763 | 0.520 | 0.058 |