Level | Geo-accumulation index | Pollution levels |
1 | Igeo ≤ 0 | No pollution |
2 | 0 ≤ Igeo ≤ 1 | Slight pollution |
3 | 1 ≤ Igeo ≤ 2 | Towards moderate pollution |
4 | 2 ≤ Igeo ≤ 3 | Moderate pollution |
5 | 3 ≤ Igeo ≤ 4 | Towards serious pollution |
6 | 4 ≤ Igeo ≤ 5 | Serious pollution |
7 | Igeo > 5 | Extremely serious pollution |