| by coal-fired power plants | 9 | other |
| from the incinerator stacks | 8 | location |
| previously | 3 | temporal |
| mercury → be → emitted | 23 |
| mercury → be emitted to → the air | 9 |
| mercury → be emitted into → the air | 8 |
| mercury → be emitted into → the atmosphere | 7 |
| mercury → emitted into → the air | 6 |
| mercury → be emitted into → the environment | 4 |
| negative | neutral | positive |
| 0.467 | 0.497 | 0.036 |
| Raw frequency | 57 |
| Normalized frequency | 0.530 |
| Modifier score | 0.600 |
| Perplexity | 88.153 |