Table 4 Classification of geo-accumulation index
Geo-accumulation index | Igeo class | Pollution intensity |
|---|---|---|
 > 5 | 6 | Very strongly polluted |
 > 4–5 | 5 | Strong to very strongly polluted |
 > 3–4 | 4 | Strongly polluted |
 > 2–3 | 3 | Moderately to strongly polluted |
 > 1–2 | 2 | Moderately polluted |
 > 0–1 | 1 | Unpolluted to moderate polluted |
 < 0 | 0 | Practically unpolluted |