Overview
Ab Manan and colleagues measured Cu, Zn, lead (Pb), and nickel (Ni) in oil-palm plantation soil and assessed geo-accumulation index values. This is supply-chain pathway evidence for plantation soil and fertilizer-associated metal loading, not palm-oil occurrence evidence.
Key numbers
The abstract reports concentration ranges of 0.76-2.00 mg kg-1 for Cu, 0.29-1.58 mg kg-1 for Zn, 0.07-0.22 mg kg-1 for Pb, and 0.01-0.05 mg kg-1 for Ni. The authors state that Cu concentrations were higher than the other measured metals and that Cu and Zn accumulation was possibly related to chemical-fertilizer application.
Table 1 reports metal concentrations in mg kg-1 as mean +/- SD:
| Soil sample | Cu | Zn | Pb | Ni |
|---|---|---|---|---|
| Point A | 0.91 +/- 0.13 | 0.46 +/- 0.19 | 0.12 +/- 0.03 | 0.02 +/- 0.007 |
| Point B | 2.00 +/- 0.19 | 1.58 +/- 0.73 | 0.22 +/- 0.04 | 0.05 +/- BDL |
| Point C | 1.18 +/- 0.22 | 0.55 +/- 0.32 | 0.09 +/- 0.02 | 0.02 +/- 0.007 |
| Point D | 1.53 +/- 0.66 | 0.90 +/- 0.37 | 0.12 +/- 0.06 | 0.03 +/- 0.02 |
| Point E | 1.87 +/- 0.23 | 0.85 +/- 0.49 | 0.13 +/- 0.01 | 0.03 +/- 0.007 |
| Point F | 1.37 +/- 0.55 | 0.53 +/- 0.21 | 0.09 +/- 0.04 | 0.04 +/- 0.02 |
| Point G | 1.26 +/- 0.24 | 0.51 +/- 0.03 | 0.09 +/- 0.02 | 0.03 +/- 0.02 |
| Point H | 1.30 +/- 0.46 | 0.76 +/- 0.25 | 0.08 +/- 0.03 | 0.05 +/- 0.007 |
| Point I | 1.29 +/- 0.23 | 0.73 +/- 0.08 | 0.12 +/- 0.02 | 0.04 +/- 0.007 |
| Control | 0.76 +/- 0.34 | 0.29 +/- 0.05 | 0.07 +/- 0.04 | 0.01 +/- BDL |
Table 3 reports Igeo values for the plantation points:
| Soil sample | Cu | Zn | Pb | Ni |
|---|---|---|---|---|
| Point A | 0.24 | 0.32 | 0.34 | 0.40 |
| Point B | 0.53 | 1.09 | 0.63 | 1.00 |
| Point C | 0.31 | 0.37 | 0.27 | 0.40 |
| Point D | 0.40 | 0.62 | 0.34 | 0.60 |
| Point E | 0.49 | 0.59 | 0.37 | 0.60 |
| Point F | 0.36 | 0.37 | 0.26 | 0.80 |
| Point G | 0.33 | 0.35 | 0.25 | 0.60 |
| Point H | 0.34 | 0.53 | 0.23 | 0.94 |
| Point I | 0.34 | 0.51 | 0.34 | 0.74 |
The paper states that all samples showed Igeo values less than 2, indicating uncontaminated to moderately contaminated soil, and that point B showed the highest Igeo values for the measured metals.
Methods (brief)
Soil samples were collected in triplicate using a hand auger from oil-palm plantation points A-I; a control sample came from undisturbed non-agricultural soil. Samples were dried, sieved to 2 mm, digested with nitric acid and hydrogen peroxide, and analyzed by ICP-OES. The paper reports total Cu, Zn, Pb, and Ni in soil, not food or oil concentrations.
Related evidence
- Soil-to-plant transfer of heavy metals
- Irrigation water and soil amendments as anthropogenic inputs to cropland
- Lead
- Nickel
- Copper
- Zinc
Update history
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