| radon → AtLocation → soil | 0.64 | |
| radon → AtLocation → the earth | 0.61 | |
| radon → AtLocation → water | 0.54 | |
| radon → AtLocation → rock | 0.53 | |
| radon → AtLocation → many regions of the country | 0.52 | |
| radon → AtLocation → the ground | 0.49 | |
| radon → AtLocation → building | 0.45 | |
| radon → AtLocation → outdoor air | 0.41 | |
| radon → AtLocation → granite | 0.40 | |
| radon → AtLocation → every state | 0.39 | |
| radon → AtLocation → elevated levels | 0.39 | |
| radon → AtLocation → school | 0.38 | |
| radon → AtLocation → small amounts | 0.37 | |
| radon → AtLocation → groundwater | 0.36 | |
| radon → AtLocation → drinking water | 0.32 | |
| radon → AtLocation → some building materials | 0.31 |