Air pollution after acute bronchiolitis is a risk factor for preschool asthma: a nested case-control study

Table 2 Concentration of subsequent ambient air pollutants in different periods in all infants acquired acute bronchiolitis

Pollutants	Mean ± SD	Min	Percentile			Max	IQR
Pollutants	Mean ± SD	Min	25%	50%	75%	Max	IQR
0-3 months
SO2(ppb)	8.27 ± 2.17	1.67	6.73	8.05	9.79	12.49	3.06
PM_2.5 (μg/m³)	43.74 ± 4.03	13.20	40.92	44.26	46.78	52.03	5.85
PM₁₀ (μg/m³)	77.30 ± 6.86	25.25	72.96	76.30	81.33	91.10	8.37
NO(ppb)	6.98 ± 2.11	1.62	5.35	6.76	8.77	15.28	3.42
NO2(ppb)	22.19 ± 3.82	2.07	19.75	22.50	25.45	29.81	5.70
NOx(ppb)	29.17 ± 5.85	3.70	25.17	29.38	34.30	43.75	9.14
0-6 months
SO2(ppb)	8.21 ± 2.15	1.66	6.69	8.01	9.71	12.33	3.02
PM_2.5 (μg/m³)	43.46 ± 4.02	13.02	40.62	44.08	46.65	51.35	6.03
PM₁₀ (μg/m³)	76.94 ± 6.81	25.06	72.66	76.02	81.04	91.10	8.38
NO(ppb)	6.92 ± 2.09	1.61	5.31	6.70	8.69	15.11	3.39
NO2(ppb)	22.09 ± 3.79	2.07	19.64	22.44	25.39	29.00	5.75
NOx(ppb)	29.01 ± 5.79	3.70	25.03	29.34	34.02	43.42	9.00
0-12 months
SO2(ppb)	8.09 ± 2.14	1.63	6.53	7.88	9.62	12.20	3.09
PM_2.5 (μg/m³)	43.04 ± 4.25	12.77	39.92	43.74	46.08	51.41	6.16
PM₁₀ (μg/m³)	76.50 ± 7.08	25.26	72.07	75.79	80.51	91.10	8.44
NO(ppb)	6.82 ± 2.08	1.62	5.21	6.51	8.63	15.10	3.42
NO2(ppb)	22.00 ± 3.80	2.07	19.57	22.48	25.24	28.87	5.66
NOx(ppb)	28.82 ± 5.80	3.70	24.75	29.06	33.80	43.38	9.05

Abbreviations: SD Standard deviation, IQR Interquartile range, SO₂ Sulphur dioxide, PM_2.5 Particulate matters with diameters at 2.5 micrometers and smaller, PM₁₀ Particulate matters with diameters at 10 micrometers and smaller, NO Nitrogen oxide, NO₂ Nitrogen dioxide, NO_X Nitrogen oxides, OR crude odds ratio, aOR Adjusted odds ratio

ISSN: 1476-069X