Table 5. Unconditional logistic regression analysis of COPD and both long-term (up to 30-years) and current H₂S exposure metrics in Rotorua city residents, 2008–2010, limited to participants with satisfactory post-bronchodilator measurements (N = 1,185).

H 2 S exposure quartile a	Time-weighted mean exposure				Maximum exposure at work, home, or school
	COPD cases (%)	Non-cases (%)	OR	95% CI	COPD cases (%)	Non-cases (%)	OR	95% CI
Long-term (30 years) exposure b
1 (Reference)	32 (10.6)	269 (89.4)	1.00	-	32 (11.0)	260 (89.0)	1.00	-
2	34 (11.4)	264 (88.6)	0.91	0.52, 1.58	28 (9.52)	266 (90.5)	0.85	0.47, 1.53
3	23 (7.96)	266 (92.0)	0.69	0.38, 1.27	29 (9.39)	280 (90.6)	0.86	0.48, 1.55
4	36 (12.1))	261 (87.9)	0.98	0.56, 1.70	36 (12.4)	254 (87.6)	1.03	0.58, 1.82
Current exposure c
1 (Reference)	38 (12.9)	256 (87.1)	1.00	-	36 (12.2)	260 (87.8)	1.00	-
2	24 (7.9)	280 (92.1)	0.59	0.33, 1.07	34 (11.9)	245 (88.2)	1.06	0.61, 1.84
3	33 (11.0)	268 (89.0)	0.90	0.53, 1.55	24 (7.4)	299 (92.6)	0.70	0.38, 1.27
4	30 (10.5)	256 (89.5)	0.69	0.40, 1.21	31 (11.1)	248 (88.9)	0.93	0.53, 1.63
TOTAL	125 (10.6)	1,060 (89.5)			125 (10.6)	1,060 (89.5)

a Adjusted for sex, age-group, ethnicity, education, income, smoking status.

b For H₂S exposure concentrations, see Table 2.

c For H₂S exposure concentrations, see Table 3.