Table 5 Summary statistics for PTE pseudo-total concentrations and soil properties for the three land covers
From: Low presence of potentially toxic elements in Singapore urban garden soils
Element | Units | Gardens | Parks | Woodlands |
|---|---|---|---|---|
Al | mg/kg | 99,070 ± 10,130 [61412–123700] | 118,850 ± 18,070 [96980–143440] | 110,590 ± 32,970 [40832–156400] |
Cd | mg/kg | bdl [bdl–3.2] | bdl [bdl–bdl] | bdl [bdl–6.4] |
Cu* | mg/kg | 42.5 ± 11.5 (b) [10.0–76.6] | 26.4 ± 6.2 (a) [9.2–69.6] | 17.6 ± 5.5 (a) [10.6–49.6] |
Pb | mg/kg | bdl [bdl–36.6] | bdl [bdl–60.8] | bdl [bdl–32.6] |
Zn* | mg/kg | 124.8 ± 33.8 (b) [70.8–164.2] | 49.8 ± 11.2 (a) [32.6–189.6] | 51.5 ± 17.4 (a) [19.2–146] |
TOC | % | 3.4 ± 1.1 [1.3–5.9] | 3.7 ± 1.1 [1.1–5.5] | 4.5 ± 0.8 [1.7–9.0] |
pH | 6.9 ± 0.6 (c) [5.8–7.8] | 6.0 ± 0.5 (b) [4.8–8.0] | 5.0 ± 0.7 (a) [4.0–8.6] | |
Clay | % | 7.8 ± 0.5 [5.8–9.7] | 6.9 ± 0.5 [5.8–8.0] | 7.8 ± 0.5 [5.4–9.6] |
Silt | % | 55.1 ± 2.1 (a) [51.5–62.2] | 67.0 ± 4.1 (c) [52.9–74.9] | 62.2 ± 6.5 (b) [41.9–78.5] |
Sand | % | 35.5 ± 1.1 (b) [27.1–39.7] | 24.4 ± 1.7 (a) [17.0–38.8] | 29.6 ± 5.5 (b) [12.0–47.8] |