| 100% | EPA | 3 | Agency concerned with clean air: Abbr. |
| 80% | EPA | 3 | Organization concerned with clean air: Abbr. |
| 80% | EPA | 3 | Group concerned with clean air: Abbr. |
| 79% | EPA | 3 | Governmental agency concerned with the Clean Air Act (Abbr.) |
| 75% | EPA | 3 | Organization concerned with clean air and water: Abbr. |
| 72% | EPA | 3 | Government agency concerned with air quality: Abbr. |
| 71% | EPA | 3 | Government group concerned with clean air (Abbr.) |
| 71% | EPA | 3 | Federal group concerned with clean air (Abbr.) |
| 70% | EPA | 3 | Agency concerned with air quality (Abbr.) |
| 68% | EPA | 3 | Federal org. concerned with clean air and water (Abbr.) |
| 64% | EPA | 3 | Org. concerned with clean air |
| 62% | EPA | 3 | Federal org. concerned with clean air and water |
| 61% | WHO | 3 | Agency concerned with international public health: Abbr. |
| 61% | OSHA | 4 | Agency concerned with employees' well-being: Abbr. |
| 61% | EPA | 3 | Organization concerned with clean energy: Abbr. |
| 60% | EPA | 3 | Clean air agency: Abbr. |
| 59% | OSHA | 4 | Agency concerned with the well-being of employees: Abbr. |
| 58% | EPA | 3 | Organization concerned with air quality: Abbr. |
| 58% | EPA | 3 | Group concerned with air quality: Abbr. |
| 57% | EPA | 3 | Federal agency concerned with climate change: Abbr. |
| 57% | CDC | 3 | Federal agency concerned with flu shots: Abbr. |
| 57% | EPA | 3 | Federal organization concerned with clean water: Abbr. |
| 57% | EPA | 3 | Government body concerned with clean water: Abbr. |
| 56% | NRC | 3 | Government agency concerned with matters related to nuclear energy safety: Abbr. |
| 56% | EPA | 3 | Federal organization concerned with air quality: Abbr. |
| 56% | EPA | 3 | Government group concerned with air quality: Abbr. |
| 56% | TSA | 3 | Organization concerned with air-travel safety: Abbr. |
| 56% | EPA | 3 | Government group concerned with air purity: Abbr. |
| 52% | ILO | 3 | U.N. agency concerned with labor (abbr) |
| 51% | EPA | 3 | Government group concerned with the air quality index: Abbr. |