Table 2. Percentage changes (95% confidence interval (CI)) in urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG)/urinary creatine (uCr) and 8-iso-prostaglandin F2α (8-iso-PGF2α)/uCr for 10 μg/m³ increase in mean concentration of particulate matter with an aerodynamic diameter of <2.5 μm (PM_2.5).

	All workers (N = 163)	Welding workers (N = 118)	Office workers (N = 45)
8-OHdG/uCr	1.24	2.15*	1.88
	(0.89, 1.59)	(1.56, 2.74)	(0.99, 2.77)
8-iso-PGF2α/uCr	3.26	8.43*	0.89
	(0.61, 5.91)	(2.14, 14.72)	(−1.27, 3.05)

Coefficients are expressed as percent changes for a 10-μg/m³ increase in mean PM_2.5 in models adjusting for sex, age, body mass index and smoothing functions of mean temperature and humidity.

^*p < 0.05.