Air Pollution by Hydrothermal Volcanism and Human Pulmonary Function

Table 4

Adjusted association between characteristics of study participants, exposure to volcanogenic soil diffuse degassing, and COPD exacerbation.

Ordinal logistic regression			Number of obs. 505; LR chi2(5) = 70.19; Prob > chi2 = <0.001
Parameter	(%)	OR (95% CI)^a	P value
Age		1.04 (1.02–1.06)	<0.001
Easy fatigue
Yes	116 (23)	1.80 (1.00–3.24)	0.046
No	389 (77)	1.00
Asthma
Yes	43 (8.5)	2.25 (1.05–4.82)	0.037
No	462 (91.5)	1.00
Smoking status
Smoker	163 (32.3)	2.11 (1.25–3.56)	0.005
Nonsmoker	342 (67.7)	1.00
Exposure to DDS
Yes (study group)	146 (28.9)	3.19 (1.82–5.58)	<0.001
No (reference group)	359 (71.1)	1.00

 ^aOR, odds ratio; 95% CI, 95% confidence interval.