Table 1 Igeo, CF, Er, DC, PLI, and PRI classes
From: Soil characterization and heavy metal pollution assessment in Orabi farms, El Obour, Egypt
Index type | Value | Environmental risk grade | Reference | |
|---|---|---|---|---|
Single indices | I geo | Igeo ≤ 0 | Practically uncontaminated | (Muller 1979) |
0 < Igeo ≤ 1 | Uncontaminated to moderately contaminated | |||
1 < Igeo ≤ 2 | Moderately contaminated | |||
2 < Igeo ≤ 3 | Moderately to heavily contaminated | |||
3 < Igeo ≤ 4 | Heavily contaminated | |||
4 < Igeo ≤ 5 | Heavily to extremely contaminated | |||
Igeo > 5 | Extremely contaminated | |||
CF | CF < 1 | Low contamination | (Hakanson 1980) | |
1 ≤ CF < 3 | Moderate contamination | |||
3 ≤ CF < 6 | Considerable contamination | |||
CF ≥ 6 | High contamination | |||
Er | Er < 40 | Low potential ecological risk | (Hakanson 1980) | |
40 ≤ Er < 80 | Moderate potential ecological risk | |||
80 ≤ Er < 160 | Considerable potential ecological risk | |||
160 ≤ Er < 320 | High potential ecological risk | |||
Er ≥ 320 | Very high ecological risk | |||
Integrated indices | DC | DC < 5 | Low contamination | (El-Bady and Samy 2014) |
5 ≤ DC < 10 | Moderate contamination | |||
10 ≤ DC < 20 | Considerable contamination | |||
DC ≥ 20 | High contamination | |||
PLI | PLI < 1 | Not polluted | (Tomilson et al. 1980) | |
PLI = 1 | Baseline levels of pollutants | |||
PLI > 1 | Polluted | |||
PRI | PRI < 150 | Low contamination | (Hakanson 1980) | |
150 ≤ PRI < 300 | Moderate contamination | |||
300 ≤ PRI < 600 | Considerable contamination | |||
PRI ≥ 600 | High contamination | |||