Mean (std. dev.) fractions of HAP metal coarse mass (ng) analyzed using ICP-MS to PM coarse mass (mg) at the background (BG) site and site A (n = 11 each), and ratios of site A mean fraction to BG mean fraction.
| BG ng mg−1 (n = 11) | Site A ng mg−1 (n = 11) | t-test p value | LOD ng/filter | Site A/BG | |
|---|---|---|---|---|---|
| Mn | 1279 (1013) | 1662 (336) | 0.26 | 6.8 | 1.30 |
| Cr | 412 (711) | 184 (61) | 0.32 | 6.6 | 0.45 |
| Ni | 37 (61) | 12 (14) | 0.21 | 8.8 | 0.32 |
| Pb | 25 (51) | 8.3 (7.0) | 0.31 | 3.9 | 0.33 |
| Co | 9.7 (11) | 4.9 (1.1) | 0.19 | 0.94 | 0.51 |
| As | 4.1 (2.0) | 2.0 (1.24) | 0.012 | 10 | 0.49 |
| Sba | 2.7 (4.0) | 1.31 (1.01) | 0.28 | 2.0 | 0.48 |
| Cdb | — | — | — | — |
a
One large outlier excluded.
b
No Cd was detected in the majority of the samples. The remaining HAP metals (beryllium, mercury, and selenium) were not analyzed.