| Similarity | Rank | |
|---|---|---|
| aquifer | 0.830 | 17613 |
| nitrate | 0.797 | 7756 |
| acidification | 0.776 | 21870 |
| pollutant | 0.760 | 10281 |
| watercourse | 0.747 | 22216 |
| hydrocarbon | 0.747 | 12320 |
| ground-water | 0.746 | 71264 |
| radon | 0.741 | 18238 |
| contaminant | 0.739 | 23773 |
| tapwater | 0.732 | 27084 |
| silting | 0.729 | 58043 |
| contamination | 0.729 | 7877 |
| sediment | 0.727 | 5603 |
| eutrophication | 0.727 | 42648 |
| dioxin | 0.726 | 17452 |
| pollution | 0.725 | 2289 |
| waterlogging | 0.725 | 41903 |
| radionuclide | 0.725 | 25560 |
| polluted | 0.718 | 13076 |
| landfill | 0.718 | 13169 |
| seawater | 0.713 | 33822 |
| precipitation | 0.713 | 14805 |
| leachate | 0.713 | 84487 |
| humic | 0.712 | 50893 |
| siltation | 0.710 | 76239 |