INDEX

Range

Classification

Samples

%

DC

<10

Low degree of contamination factor

10

100

EF

≤1

Background contamination

2

20

1 - 2

Minimal enrichment

8

80

Er

Er < 40

Low potential risk

10

100

RI

RI < 150

Low ecological risk

10

100

PLI

=0

perfection

2

20

<1

No pollution

8

80

Igeo

0 - 1

Unpolluted to moderately polluted

10

100