Table 1 Classification of enrichment factor (EF) and geoaccumulation indices (Igeo)
EF values | Class of EF | |
< 2 | Depletion to minimal enrichment | |
2–5 | Moderate enrichment | |
5–20 | Significant enrichment | |
20–40 | Very high enrichment | |
> 40 | Extremely high enrichment | |
Grade | Igeo values | Soil quality |
0 | < 0 | Practically unpolluted |
1 | 0–1 | Unpolluted to moderately polluted |
2 | 1–2 | Moderately polluted |
3 | 2–3 | Moderately polluted to heavily polluted |
4 | 3–4 | Heavily polluted |
5 | 4–5 | Heavily polluted to extremely polluted |
6 | > 5 | Extremely polluted |