SN | Trace element pollution indices | Formulae | Reference |
1 | Degree of Contamination |
| [25] |
2 | Enrichment factor |
| [26] |
3 | Ecological risk factor |
| [27] |
4 | Ecological risk index |
| [27] |
5 | pollution load index |
| [28] |
6 | Geo-accumulation index |
| [29] |