Early childhood traffic-related air pollution and risk of allergic rhinitis at 2–4 years of age modification by family stress and male gender: a case-control study in Shenyang, China

Table 2 Distribution of ambient air pollution concentrations (μg/m³)

Air pollutant	Mean	Percentile distribution			IQR
Air pollutant	Mean	P₂₅	P₅₀	P₇₅	IQR
PM₁₀	88	75	88	95	20
SO₂	26	20	26	34	14
NO₂	31	23	31	41	18
CO	970	906	970	1260	354
O₃	92	80	92	102	22

ISSN: 1347-4715