Effect of Ambient PM2.5-Bound BbFA and DahA on Small Airway Dysfunction of Primary Schoolchildren in Northeast China

Table 2

Characteristics of the study population.

Variable	School A	School B
Number	153	151
Sex (Male %)	82 (53.6%)	65 (43.0%)	0.066
Age (years (mean ± SD))	10.11 ± 0.94	10.37 ± 0.96	0.517
Weight (kg (mean ± SD))	42.61 ± 10.62	40.46 ± 9.53	0.087
Height (cm (mean ± SD))	142.05 ± 9.11	139.76 ± 8.40	0.283
Smoking in family (number (%))	32 (20.9%)	42 (27.8%)	0.085
Keeping pet at home (number (%))	35 (22.9%)	19 (12.6%)	0.019
Air purifier (number (%))	21 (13.7%)	25 (16.6%)	0.491
Distance of outdoor vehicular traffic			0.030
>100 m	51 (33.3%)	64 (42.4%)
20∼100 m	67 (43.8%)	44 (29.1%)
<20 m	35 (22.9%)	43 (28.5%)
Urinary MDA (μmol/L)	2.03 ± 1.05	2.57 ± 1.34	0.041
Urinary CRP (mg/L)	0.83 ± 0.31	1.01 ± 0.42	0.082

MDA, malondialdehyde; CRP, C-reactive protein.