Table 5.

Contamination rank corresponding to geo-accumulation index.

Igeo Values	Igeo ≤ 0	0 < Igeo ≤ 1	1 < Igeo ≤ 2	2 < Igeo ≤ 3	3 < Igeo ≤ 4	4 < Igeo ≤ 5	Igeo > 5
Rank	0	1	2	3	4	5	6
Pollution levels	No pollution	Mild pollution	Light pollution	Moderate pollution	High pollution	Heavy pollution	Extreme pollution