Table 3.
Source contributions to PM2.5 mass (μg/m3) and element (ng/m3) concentrations in Hartford, CT
| Regional Sulfur | Motor Vehicles | Road Dust | Oil Combustion | Sea Salt | Estimated | Measured | %MRE | |
|---|---|---|---|---|---|---|---|---|
| EC | 39.7 | 317.1 | 17.4 | 142.9 | 0.5 | 517.6 | 553.8 | 6.5 |
| Zn | 0.2 | 10.9 | 0.3 | 2.9 | 0.0 | 14.4 | 15.0 | 4.2 |
| Pb | 0.5 | 1.1 | 0.3 | 0.7 | 0.1 | 2.7 | 3.1 | 13.4 |
| Cu | 0.3 | 1.1 | 0.2 | 0.2 | 0.0 | 1.9 | 2.2 | 13.8 |
| Br | 0.3 | 0.4 | 0.2 | 0.5 | 0.1 | 1.5 | 1.6 | 9.1 |
| Si | 4.5 | 3.9 | 36.3 | 1.9 | 0.0 | 46.6 | 49.2 | 5.3 |
| Fe | 7.9 | 22.9 | 21.1 | 4.7 | 0.5 | 57.1 | 60.3 | 5.3 |
| Al | 4.9 | 1.8 | 18.2 | 0.7 | 0.1 | 25.8 | 27.5 | 6.2 |
| Ca | 2.3 | 6.3 | 10.1 | 0.7 | 0.6 | 20.0 | 21.0 | 4.8 |
| Ti | 0.6 | 0.8 | 1.8 | 0.0 | 0.0 | 3.3 | 4.1 | 20.3 |
| S | 824.2 | 142.5 | 62.9 | 163.9 | 0.0 | 1193.5 | 1201.8 | 0.7 |
| K | 5.7 | 17.0 | 10.2 | 7.3 | 1.0 | 41.2 | 46.3 | 11.1 |
| V | 0.1 | 0.1 | 0.1 | 2.6 | 0.0 | 2.9 | 2.9 | 0.0 |
| Ni | 0.1 | 0.5 | 0.1 | 1.6 | 0.0 | 2.2 | 2.5 | 9.7 |
| Na | 69.2 | 3.5 | 20.3 | 25.5 | 6.6 | 125.0 | 129.1 | 3.1 |
| Cl | 0.0 | 0.0 | 0.0 | 0.1 | 6.9 | 7.0 | 7.1 | 1.8 |
| PM2.5 | 5.0 | 3.1 | 0.8 | 2.2 | 0.2 | 11.3 | 11.9 | 5.4 |
Note: The measured values are based on the concentration values excluding 16 samples affected by unusual events as described in Section 2.2.