Table 1.
Summary statistics of Cd, Cu, Hg, Pb, and Zn (mg/kg) in rhizosphere soil samples by portable X-ray fluorescence (PXRF) spectrometry for polluted soil in Turda, Romania.
| Hg | Pb | Cd | Cu | Zn | |
|---|---|---|---|---|---|
| Minimum | 35 | 54 | <LOD a | 40 | 226 |
| Maximum | 4530 | 516 | <LOD a | 1699 | 2198 |
| Mean | 1195 | 283 | - c | 586 | 661 |
| Median | 756 | 266 | - c | 482 | 487 |
| SD | 1107 | 125 | - c | 456 | 477 |
| Skewness | 1.70 | 0.19 | - c | 0.98 | 2.11 |
| Kurtosis | 3.35 | −0.47 | - c | 0.53 | 5.03 |
| Sensitive soil threshold alert b | 1 | 50 | 3 | 100 | 300 |
| Sensitive soil threshold intervention b | 2 | 100 | 5 | 200 | 600 |
| Industrial soil threshold alert b | 4 | 150 | 5 | 250 | 700 |
| Industrial soil threshold intervention b | 10 | 1000 | 10 | 500 | 1500 |
a LOD—limit of detection, 5 mg/kg Cd; b Soil threshold values according to Romanian regulations [84]. c The parameters could not be calculated for Cd, as the values detected in the rhizosphere soil samples were under the LOD.