Table 2.

Single-pollutant and two-pollutant models for the association between ambient air particulate matter and serum thromboxane B2 levels

Model	COPD		Non-COPD		Pinteraction
	Change, % (95% CI)	P	Change, % (95% CI)	P
UFPs	25.4 (12.8, 39.4)	< 0.001	11.2 (1.1, 22.3)	0.03	0.01
UFPs + PM2.5	22.4 (9.2, 37.3)	< 0.001	10.5 (0.4, 21.7)	0.04	0.04
UFPs + NO2	23.6 (9.9, 38.9)	< 0.001	11 (0.8, 22.3)	0.04	0.03
UFPs + SO2	22.3 (9.1, 37.1)	< 0.001	8.9 (− 1.7, 20.6)	0.10	0.01
UFPs + CO	23.1 (10.2, 37.6)	< 0.001	10 (− 0.2, 21.2)	0.06	0.02
UFPs + O3	25.7 (13, 39.8)	< 0.001	12.4 (1.9, 24)	0.02	0.02
PM2.5	7.4 (1.9, 13.1)	0.008	0.7 (− 7.6, 9.9)	0.87	0.11
PM2.5 + UFPs	5.7 (0.3, 11.4)	0.04	− 0.4 (− 8.6, 8.5)	0.93	0.13
PM2.5 + NO2	5.1 (− 4.6, 15.8)	0.31	− 1 (− 11.9, 11.2)	0.86	0.13
PM2.5 + SO2	3.9 (− 2.7, 11)	0.25	− 3.8 (− 13.3, 6.7)	0.46	0.06
PM2.5 + CO	4.1 (− 4, 12.8)	0.33	− 3.6 (− 14.7, 8.9)	0.56	0.07
PM2.5 + O3	7.5 (1.5, 13.7)	0.01	0.8 (− 7.8, 10.1)	0.86	0.11

Shown are percent changes (95% CIs) in serum TxB2 levels per 10³/cm³ increase in the 6-day UFP average and per 10 μg/m³ increase in the 14-day PM_2.5 average