Income Group | Sample No. | Heavy metal (mg∙kg−1) | ||||||
As | Pb | Cd | Cr | Cu | Zn | Hg | ||
Lower | 1 | 0.09 | 4.58 | 0.03 | 1.91 | 0.004 | 15.90 | 0.12 |
2 | 1.17 | 7.90 | 0.09 | 2.98 | 0.001 | 21.23 | 0.14 | |
Lower middle | 1 | 1.98 | 11.09 | 0.04 | 4.78 | 0.004 | 32.90 | 0.21 |
2 | 4.58 | 16.73 | 0.93 | 15.98 | 0.007 | 34.85 | 0.92 | |
Middle | 1 | 8.90 | 16.73 | 3.23 | 56.83 | 0.007 | 43.11 | 0.12 |
2 | 11.46 | 14.79 | 2.62 | 54.71 | 0.02 | 51.11 | 0.13 | |
High | 1 | 16.78 | 16.77 | 3.33 | 61.67 | 0.06 | 67.55 | 0.22 |
2 | 21.34 | 15.96 | 4.24 | 74.19 | 0.09 | 65.46 | 0.01 |