Correlation between PM10 and other environmental variables in the study locations
| City | Temperature (°C) | Relative humidity |
|---|---|---|
| Birmingham | 0.26 | −0.3 |
| Boulder | −0.07 | −0.23 |
| Canton | 0.42 | −0.16 |
| Chicago | 0.36 | −0.3 |
| Cincinnati | 0.44 | −0.00 |
| Colorado Springs | −0.34 | −0.11 |
| Columbus | 0.41 | −0.07 |
| Detroit | 0.37 | −0.14 |
| Minneapolis/St Paul | 0.29 | −0.35 |
| New Haven | 0.05 | −0.15 |
| Pittsburgh | 0.45 | −0.23 |
| Provo-Orem | −0.41 | 0.33 |
| Seattle | −0.22 | −0.11 |
| Spokane | −0.01 | −0.19 |