Index

Range

Classification

Samples

%

DC

<10

Low degree of contamination factor

10

100

EF

≤1

Background contamination

8

80

1 - 2

Minimal enrichment

2

20

Er

Er < 40

Low potential risk

10

100

RI

RI < 150

Low ecological risk

10

100

PLI

<1

No pollution

10

100

Igeo

≤0

Unpolluted

Li, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Cd

0 - 1

Unpolluted to moderately polluted

Ba, Pb