Table 2.
Outcome levels for electric and diesel scenarios and percent changes in biomarker levels
| Biomarker | Electric (mean ± SD) | Diesel (mean ± SD) | % Change (95% CI) | p-value | |
|---|---|---|---|---|---|
| Urinary excretion | 1-OHP (μmol/mol creatinine) | 0.049 ± 0.083 | 0.027 ± 0.019 | −12.2 (− 32.3; 14.0) | 0.331 |
| 2-OHF (μmol/mol creatinine) | 0.075 ± 0.067 | 0.070 ± 0.061 | 0.6 (− 17.3; 22.4) | 0.952 | |
| 1-NAPH (μmol/mol creatinine) | 0.851 ± 0.603 | 0.671 ± 0.560 | −20.0 (−44.3; 4.3) | 0.107 | |
| 2-NAPH (μmol/mol creatinine) | 2.084 ± 2.272 | 1.861 ± 1.679 | −0.4 (−20.7; 25.2) | 0.975 | |
| Lung function | FVC (L) | 4.20 ± 1.24 | 4.18 ± 1.16 | −2.3 (−4.7; 0.25) | 0.077 |
| FEV1 (L) | 3.32 ± 0.96 | 3.24 ± 0.96 | −3.6 (−5.5; −1.6) | 0.0003*** | |
| FEV1/FVC (%) | 79.1 ± 6.8 | 77.2 ± 9.2 | −1.8 (− 3.8; 0.2) | 0.073 | |
| PEF (L/s) | 7.26 ± 2.13 | 7.15 ± 2.42 | −5.6 (− 10.7; − 0.5) | 0.031* | |
| Cardiovascular function | Ln.RHI | 0.57 ± 0.25 | 0.55 ± 0.28 | −1.4 (− 26.5; 23.7) | 0.913 |
| NIV | 2.26 ± 1.06 | 2.21 ± 0.71 | − 3.7 (− 34.6; 27.3) | 0.817 | |
| pNN50 (%) | 0.06 ± 0.08 | 6.54 ± 0.07 | 4.6 (− 13.8; 23.0) | 0.626 | |
| RMSSD (ms) | 41.84 ± 30.93 | 36.39 ± 19.02 | − 3.5 (− 22.1; 19.7) | 0.326 | |
| SDNN (ms) | 48.16 ± 24.29 | 44.24 ± 16.76 | −2.1 (− 14.9; 12.7) | 0.773 | |
| LF (ms2) | 160.2 ± 59.5 | 195.9 ± 78.8 | 16.5 (5.9; 27.0) | 0.002** | |
| HF (ms2) | 153.6 ± 57.6 | 151.8 ± 67.5 | 2.0 (− 7.5; 11.5) | 0.681 | |
| LF/HF | 1.27 ± 0.83 | 1.70 ± 1.37 | 18.5 (−5.5; 48.6) | 0.141 | |
| AI normalized to heart rate of 75 bpm (%) | −8.26 ± 11.79 | −6.26 ± 14.68 | 1.6 (−2.2; 5.5) | 0.405 | |
| DP (mm Hg) | 81.2 ± 11.4 | 82.3 ± 10.8 | 1.2 (−2.9; 5.2) | 0.566 | |
| SP (mm Hg) | 135.1 ± 16.1 | 134.4 ± 17.9 | −1.0 (−4.9; 2.9) | 0.630 | |
| DNA damage | SB (lesions/106 bp) | 0.12 ± 0.13 | 0.18 ± 0.13 | 46.3 (5.0; 100.9) | 0.025* |
| Fpg-sensitive sites (lesions/106 bp) | 0.62 ± 0.15 | 0.58 ± 0.12 | −5.0 (−11.1; 1.1) | 0.109 | |
| Adhesion molecules | ICAM-1 (ng/mL) | 35.04 ± 7.28 | 34.34 ± 6.88 | −2.5 (−8.3; 3.7) | 0.426 |
| VCAM-1 (ng/mL) | 134.2 ± 36.2 | 129.6 ± 35.8 | −3.2 (−10.5; 4.7) | 0.416 | |
| Acute phase proteins | SAA (mg/L) | 32.09 ± 41.51 | 36.46 ± 47.35 | 11.1 (−17.8; 50.2) | 0.493 |
| CRP (mg/L) | 1.83 ± 2.29 | 1.90 ± 2.48 | −12.3 (−47.5; 46.4) | 0.615 | |
Percent change was estimated by mixed-effects model adjusted for age and sex, comparing diesel with electric scenarios
CI confidence interval, SD standard deviation, 1-OHP 1-hydroxypyrene, 2-OHF 2-hydroxyfluorene, 1-NAPH 1-naphthol, 2-NAPH 2-naphthol, FVC forced vital capacity, FEV1 forced expiratory volume in one second, PEF peak expiratory flow rate, Ln.RHI reactive hyperemia index with natural logarithmic transformation (the percent change was back transformed), NIV nitroglycerin-induced vasodilation, pNN50 proportion of successive NN intervals differing by more than 50 milliseconds divided by total number of NN intervals, RMSSD square root of the mean squared differences of successive NN intervals, SDNN standard deviation of all NN intervals, LF low frequency component (0.04–0.15 Hz), HF high frequency component (0.15–0.4 Hz), AI augmentation index, DP diastolic blood pressure, SP systolic blood pressure, SB DNA strand breaks, ICAM-1 intercellular cell adhesion molecule-1, VCAM-1 vascular cell adhesion molecule-1, SAA serum amyloid A, CRP C-reactive protein; *p < 0.05; **p < 0.01; ***p < 0.001