Table 4

Association of oral cancer with PM_2.5 in Taiwanese men

Variables	Model 1			Model 2
Variables	OR	95% CI	P values	OR	95% CI	P values
PM_2.5
PM_2.5<26.74	1	–	–	1	–	–
26.74≤PM_2.5<32.37	0.91	0.75 to 1.10	0.332	0.91	0.75 to 1.11	0.342
32.37≤PM_2.5<40.37	1.00	0.84 to 1.20	0.964	1.01	0.84 to 1.20	0.955
PM_2.5≥40.37	1.42	1.17 to 1.73	0.001*	1.43	1.17 to 1.74	<0.0001*
PM_10−2.5†
PM_10−2.5<18.88	1	–	–	1	–	–
18.88≤PM_10−2.5<23.66	0.95	0.80 to 1.11	0.511	0.95	0.81 to 1.12	0.517
23.66≤PM_10−2.5<32.42	1.06	0.91 to 1.25	0.451	1.07	0.91 to 1.25	0.447
PM_10−2.5≥32.42	1.10	0.89 to 1.37	0.367	1.10	0.89 to 1.36	0.373
SO₂
SO₂<2.96	1	–	–	1	–	–
2.96≤SO₂<3.61	0.82	0.67 to 1.01	0.064	0.83	0.67 to 1.02	0.070
3.61≤SO₂<4.43	0.92	0.75 to 1.14	0.454	0.93	0.75 to 1.14	0.464
SO₂≥4.43	0.86	0.70 to 1.07	0.171	0.86	0.70 to 1.07	0.174
O₃
O₃<28.69	1	–	–	1	–	–
28.69≤O₃<30.97	1.26	1.12 to 1.42	<0.0001*	1.26	1.11 to 1.42	<0.0001*
30.97≤O₃<33.79	0.94	0.79 to 1.11	0.472	0.94	0.80 to 1.11	0.480
O₃≥33.79	1.00	0.84 to 1.19	0.975	1.00	0.84 to 1.19	0.984
Age	1.00	0.99 to 1.00	0.286	1.00	0.10 to 1.00	0.769
Betel chewing
Never	1	–	–	1	–	–
Occasional	1.01	0.81 to 1.28	0.905	0.88	0.70 to 1.12	0.306
Frequent	1.74	1.39 to 2.18	<0.0001*	1.42	1.11 to 1.83	0.006*
Test for trend	<0.0001*			0.0297*
Smoking
Never	–	–	–	1	–	–
Occasional	–	–	–	1.29	1.14 to 1.47	<0.0001*
Frequent	–	–	–	1.40	1.15 to 1.70	0.001*

Model 1: adjusted for PM_10−2.5, SO₂, O₃, age, and betel quid chewing.
Model 2: adjusted for PM_10−2.5, SO₂, O₃, age, betel quid chewing, and smoking.
*P<0.05.
†PM₁₀ minus PM_2.5.
O₃, ozone; PM, particulate matter; SO₂, sulfur dioxide.