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Chemical characteristics of soil samples
| Soil source | Cation exchange capacity (meq/100 g) | Organic matter content (%) | pH | Total Pb concn (mmol · kg of soil−1) | pPb2+a |
|---|---|---|---|---|---|
| Industrial (I soils) | 25.1 ± 0 | 2.7 ± 0.5 | 7.8 ± 0.2 | 4.8 | 8.2 |
| Residential (R soils) | 17.6 ± 1.8 | 3.5 ± 1.0 | 7.4 ± 0.1 | 3.9 | 8.9 |
| Agricultural (A soils) | 21.5 ± 0.1 | 5.0 ± 1.5 | 7.0 ± 0.1 | 0.0039 | 9.5 |
pPb2+ (the negative log of free Pb2+ activity) was calculated from the pH and the total Pb content (27).
