Table 3 Odds ratio of ventricular arrhythmia associated with an interquartile range increase (IQR) in the 6 (lag 0–5), 12 (lag 0–11), 24 (lag 0–23), and 48 (lag 0–47) hour moving average pollutant concentrations; St Louis ICD Study, 2001–02.

Pollutant	IQR	Moving average	No. subjects	No. VAs	Odds ratio	95% CI
Elemental carbon	0.6 µg/m3	6 h	52	116	1.02	0.79 to 1.33
	0.6 µg/m3	12 h	50	113	1.16	0.91 to 1.48
	0.5 µg/m3	24 h	51	118	1.18	0.93 to 1.50
	0.5 µg/m3	48 h	52	118	1.15	0.85 to 1.54
Nitrogen dioxide	10 ppb	6 h	55	138	1.10	0.79 to 1.55
	9 ppb	12 h	55	135	1.18	0.85 to 1.65
	6 ppb	24 h	55	134	1.22	0.94 to 1.60
	5 ppb	48 h	55	127	1.07	0.79 to 1.44
Sulphur dioxide	4 ppb	6 h	55	138	1.04	0.96 to 1.12
	5 ppb	12 h	55	137	1.17	1.04 to 1.30
	5 ppb	24 h	55	136	1.24	1.07 to 1.44
	4 ppb	48 h	55	133	1.15	1.00 to 1.34