Table 1.
Summary of the average aerosol concentrations and characteristics during exposures in the chamber
| HVOPM+NOx | HVONOx | FA | ||
|---|---|---|---|---|
| Particle phase | PM1 (µg m−3) (Gravimetric) | 93 ± 13 | ~ 1a | ~ 1a |
| PM1 Total Carbon (TC, µg m−3) | 82 ± 10 | < 1 | < 1 | |
| EC/TC (%) | 66 ± 3 | – | – | |
| OC/TC (%) | 34 ± 3 | – | – | |
| PM1 (µg m−3) (SMPS and ) | 81 ± 9 | 0.0 ± 0.0 | 0.5 ± 0.5 | |
| GMDmass (nm) | 114 | – | – | |
| GSDmass (nm) | 1.48 | – | – | |
| PN (cm−3) | 3.0 · 105 | 9.0 · 101 | 7.1 · 101 | |
| PN std. dev | 0.3 · 105 | 4.1 · 101 | 4.3 · 101 | |
| GMDPN (nm) | 71 | 47.2 | – | |
| GSDPN (nm) | 1.64 | 1.46 | – | |
| Surface area (cm−2 cm−3) | 9.5 · 10–5 | – | – | |
| Surface area std. dev (cm−2 cm−3) | 1.4 · 10–5 | – | – | |
| Particle phase PAHsb (ng m−3) | 43 ± 3 | 0.3 ± 0.7 | 0.2 ± 0.2 | |
| Gas phase | Gas phase PAHsb (ng m−3) | 850 ± 48 | 97 ± 11 | 116 ± 29 |
| Formaldehyde (µg m−3) | 51 ± 6 | < 8 | < 8 | |
| Sum BTEX (µg m−3) | 7.9 ± 2.5 | 1.7 ± 0.3 | 1.3 ± 0.1 | |
| VOCs (ppb) | 333 ± 69 | 11 ± 5 | < 10 | |
| NO (ppm) | 3.4 ± 0.1 | 2.0 ± 0.1 | < 0.001 | |
| NO2 (ppm) | 0.57 ± 0.04 | 0.70 ± 0.04 | < 0.001 | |
| NO/NO2 ratio | 5.7 | 2.9 | - | |
| CO2 (ppm) | 1344 ± 143 | 1332 ± 135 | 813 ± 140 |
All values are the average of all exposures (n = 5–6) of a given type with ± 1 SD. Full compound analyses of PAHs and BTEX are found in Additional file 1: A and B, respectively
a There were large uncertainties in the gravimetric mass analysis at low/no mass concentrations. The mass concentrations were in the range of the blank filters (− 1 ± 3 µg)
b 33 native and alkylated, 10 oxy- and 17 nitro-PAHs were included in the analysis