Table 2.
Risk assessment of heavy metals in source river sediment, wetland sediments/soils, and regional background soils (mg/kg, dried weight)
| Heavy metals | TEL | PEL | Hangzhou–Jiaxing–Huzhou plain soil layer A | Source river | Within wetland, n = 84 | Percentage | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Max | Min | Mean | <TEL | TEL ~ PEL | > = PEL | |||||
| Cd | 0.596 | 3.53 | 0.152 | 0.09 | 0.28 | 0.05 | 0.12 | 100.0% | 0.0% | 0.0% |
| Cr | 37.3 | 90 | 77.6 | 151.07 | 251.95 | 70.32 | 121.57 | 0.0% | 15.5% | 84.5% |
| Cu | 35.7 | 197 | 30.8 | 32.34 | 39.33 | 12.33 | 22.07 | 98.8% | 1.2% | 0.0% |
| Ni | 18 | 36 | 32.4 | 55.88 | 73.70 | 21.74 | 38.93 | 0.0% | 46.4% | 53.6% |
| Zn | 123 | 315 | 92.7 | 167.52 | 427.93 | 21.96 | 112.95 | 65.5% | 32.1% | 2.4% |
| Pb | 35 | 91.3 | 30.4 | 14.68 | 64.20 | 5.22 | 25.37 | 88.1% | 11.9% | 0.0% |
Note: TEL: threshold effect level; PEL: probable effect level. The plain text, italics, and boldface regarding the contents represent rare, occasional, and frequent negative ecological risks, respectively. Hangzhou–Jiaxing–Huzhou plain soil layer A data are from (Wang et al. 2007).