Table 4.
Descriptive statistics for metal contents (mg kg-1) in Estarreja Chemical Complex (ECC) agricultural soils, soil top layer local background (BG) values from Inácio [104] and (CEQG) Canadian Environmental Quality Guidelines (mg kg− 1) for agricultural land use [107].
| Al | Cu | Hg | Mn | Fe | Pb | Zn | |
|---|---|---|---|---|---|---|---|
| Minimum | 0.31 | 3 | 0.03 | 36 | 0.26 | 6 | 16 |
| Mean | 0.60 | 33 | 1.5 | 120 | 0.66 | 33 | 84 |
| Median | 0.56 | 23 | 0.15 | 110 | 0.62 | 23 | 67 |
| Maximum | 1.15 | 103 | 14 | 255 | 1.15 | 109 | 199 |
| SD | 0.21 | 27 | 4 | 56 | 0.2 | 23 | 44 |
| Cambisoil | 2.14 | 2 | 0.05 | 251 | 2.39 | 20 | 55 |
| Podzol | 0.13 | 12 | 0.05 | 154 | 0.17 | 6 | 4 |
| BG | 1.14 | 7 | 0.05 | 203 | 1.28 | 13 | 30 |
| CEQG | NA | 62 | 0.16 | NA | NA | 45 | 290 |
| % > BG | 0 | 96 | 100 | 12 | 0 | 84 | 96 |
| % > CEQG | NA | 15 | 35 | NA | NA | 23 | 0 |
Note: In bold are the trace elements (TE) values relatively higher than the respective guidelines; SD: standard deviation.