Table 1 Pollutions indices [33]
Indexes | Used formulas | Values |
|---|---|---|
Contamination Factor (CF) | CFn = Cn sample/Cn background∗ | CF<1 low contamination |
1 ≤ CF<3 moderate contamination | ||
3 ≤ CF<6 considerable contamination | ||
CF ≥ 6 very high pollution | ||
Enrichment Factor (EF) | EFn = (Cn/Fe) sample/(Cn/Fe) background∗∗ | EF<2 natural variability |
2<EF<5 moderate enrichment | ||
5<EF<20 significant enrichment | ||
20<EF<40 very high enrichment | ||
EF>40 extremely high enriched | ||
Geochemical Index (Igeo) | \(\text{I}_{\text{geo}}=\log 2(\text{C}_{\text{n}}/ 1.5\text{B}_{\text{n}})^{***}\) | Igeo<0.42 unpolluted |
0.42<Igeo<1.42 low unpolluted | ||
1.42<Igeo<3.42 moderately polluted | ||
3.42<Igeo<4.42 strongly polluted | ||
Igeo>4.42 extremely polluted |