Trace metal | Co | Cu | Ni | Cr | Zn | Mn | Cd | As |
---|---|---|---|---|---|---|---|---|
Metal contamination factor | 5.0 | 5.0 | 5.0 | 2.0 | 1.0 | 1.0 | 30.0 | 10.0 |
 | Risk Index Value | Environmental Risk Categories | ||||||
1 | Ë‚ 150 | Low ecological risk | ||||||
2 |  ≥ 150 ˂ 300 | Moderate ecological risk | ||||||
3 |  ≥ 300 ˂ 600 | Considerable ecological risk | ||||||
4 |  ≥ 600 | Very high ecological risk |