Lung cancer risk and pollution in an industrial region of Northern Spain: a hospital-based case-control study

Table 4 Odds ratios of lung cancer, overall and by histologic subtype, in Asturias' two main hospital catchment areas, by exposure category

	Total				Squamous cell carcinoma			Adenocarcinoma			Small cell carcinoma
	Controls	Cases	OR (95%CI)^a	P-value^b	Cases	OR (95%CI)^a	P-value^b	Cases	OR (95%CI)^a	P-value^b	Cases	OR (95%CI)^a	P-value^b
	N	N			N			N			N
Gijon
Unexposed	248	211	Reference		80	Reference		75	Reference		36	Reference
Industrial	36	41	1.51 (0.85-2.66)		15	1.57 (0.73-3.39)		13	1.01 (0.46-2.21)		10	2.17 (0.86-5.46)
Urban	36	55	2.17 (1.25-3.76)		22	3.07 (1.42-6.60)		19	2.01 (1.00-4.05)		6	1.51 (0.52-4.37)
Semi-urban	35	48	1.66 (0.94-2.92)	0.017	19	1.91 (0.90-4.03)	0.018	16	1.53 (0.72-3.22)	0.218	10	2.01 (0.81-5.03)	0.237
Aviles
Unexposed	122	126	Reference		51	Reference		25	Reference		25	Reference
Industrial	18	28	0.96 (0.45-2.06)		6	0.50 (0.16-1.58)		11	2.12 (0.80-5.65)		6	0.85 (0.25-2.86)
Urban	18	13	0.95 (0.38-2.34)		6	0.88 (0.26-3.03)		6	1.70 (0.50-5.79)		0	-
Semi-urban	18	9	0.56 (0.22-1.45)	0.693	1	0.19 (0.02-1.60)	0.214	3	1.05 (0.25-4.33)	0.453	2	0.63 (0.11-3.69)	0.238

^aORs were estimated from a multiple logistic regression model that included age, sex, tobacco consumption, family history of cancer, and occupation
^bP-value for the whole effect of outdoor exposure

ISSN: 1476-072X