Demographics, lung function data and exposure to air pollution of the study infants
| Median | Interquartile range | Range | |
| Anthropometric data# | |||
| Age at study date days | 34 | 32–37 | 25–55 |
| Weight at study date kg | 4.3 | 4.0–4.8 | 2.9–6.3 |
| Length at study date cm | 55.0 | 53.3–56.8 | 48.0–61.5 |
| Gestational age at birth weeks | 40.0 | 39.0–40.9 | 37.0–42.3 |
| Birthweight kg | 3.4 | 3.1–3.7 | 2.2–4.9 |
| Lung function data at 5 weeks of age | |||
| Tidal breathing parameters¶,+ | |||
| Minute ventilation mL·min−1 | 1401 | 1239–1566 | 733–2334 |
| Respiratory rate breaths·min−1 | 44.4 | 37.8–51.2 | 24.1–79.3 |
| Tidal volume mL | 32.3 | 28.1–36.6 | 21.0–51.1 |
| Tidal expiratory flow mL·s−1 | 41.5 | 35.6–49.1 | 20.0–79.6 |
| Tidal inspiratory flow mL·s−1 | 53.9 | 47.9–59.0 | 30.0–82.0 |
| Ratio tPTEF/tE | 34.4 | 27.9–41.7 | 14.8–73.3 |
| Multiple-breath washout§,ƒ | |||
| FRCao mL | 97.2 | 85.1–108.0 | 56.3–145.4 |
| FRCao per weight mL·kg−1 | 22.2 | 19.7–25.2 | 12.3–35.8 |
| LCI | 6.9 | 6.4–7.4 | 5.5–10.1 |
| Inflammatory markers¶,## | |||
| eNO¶¶ ppb | 13.4 | 10.2–16.6 | 1.8–34.9 |
| NO output¶¶,++ nL·s−1 | 0.582 | 0.458–0.721 | 0.068–1.422 |
| Outdoor temperature °C | 10 | 3–15 | −6–27 |
| Subjects' homes | |||
| Distance to measurement station§§ km | 42.1 | 39.6–47.4 | 15.9–136.4 |
| Distance to 4-m road§§ m | 79 | 38–155 | 3–747 |
| Distance to 6-m road§§ m | 190 | 83–401 | 3–3794 |
| Mean daily pre-natal exposure to air pollution | |||
| PM10 μg·m−3 | 22.1 | 20.2–23.8 | 17.1–25.7 |
| NO2 μg·m−3 | 15.8 | 14.7–17.0 | 11.8–19.6 |
| O3ƒƒ μg·m−3 | 86.7 | 79.6–94.9 | 74.1–111.7 |
| Mean daily post-natal exposure to air pollution | |||
| PM10 μg·m−3 | 20.0 | 16.6–23.4 | 10.6–49.6 |
| NO2 μg·m−3 | 15.1 | 10.9–19.7 | 7.0–31.2 |
| O3ƒƒ μg·m−3 | 87.5 | 56.3–109.9 | 25.0–156.2 |
tPTEF: time to peak tidal expiratory flow; tE: expiratory time; FRCao: functional residual capacity at airway opening; LCI: lung clearance index; eNO: exhaled nitric oxide (NO); PM10: particles with a 50% cut-off aerodynamic diameter of 10 μm; NO2: nitrogen dioxide; O3: ozone. #: n = 222; ¶: calculated as the mean value of 100 breaths without sighs; +: n = 221; §: calculated as the mean value of all technically acceptable washout measurement traces; ƒ: n = 181; ##: n = 205; ¶¶: measured in the third quartile of the expiratory cycle; ++: calculated as eNO×expiratory flow; §§: for one subject, this could not be determined, as no geographic information system data were available; ƒƒ: based on maximum hourly value of each day.