Geochemical and Geophysical Study in a Degraded Area Used for Disposal of Sludge from a Water Treatment Plant

Table 3

Classification of the parameters by the geoaccumulation index, according to the degree of pollution.

Classification	Class of 𝐼geo	𝐼geo
Extremely polluted	6	>5
Heavily to extremely polluted	5	>4 a 5
Heavily polluted	4	>3 a 4
Moderately to heavily polluted	3	>2 a 3
Moderately polluted	2	>1 a 2
Unpolluted to moderately polluted	1	>0 a 1
Practically unpolluted	0	<0