| from the oxidized ore | 6 | other |
| from coal-combustion byproducts | 3 | cause |
| from cigarette butts | 2 | other |
| metal → be → leached | 11 |
| metal → can → leach | 5 |
| negative | neutral | positive |
| 0.258 | 0.705 | 0.037 |
| Raw frequency | 16 |
| Normalized frequency | 0.307 |
| Modifier score | 0.500 |
| Perplexity | 66.537 |