Traffic air pollution and mortality from cardiovascular disease and all causes: a Danish cohort study

Table 3 Mortality rate ratios associated with different exposure measures at residential addresses

	Mortality rate ratio^a(95% confidence interval)
Exposure	All causes (n = 5534)	Cardiovascular disease (n = 1285)	Ischemic heart disease (n = 548)	Cerebrovascular disease (n = 292)	Other cardiovascular disease (n = 376)
NO₂ from 1971 onwards^b	1.13 (1.04-1.23)	1.26 (1.06-1.51)	1.12 (0.85-1.47)	1.11 (0.76-1.63)	1.72 (1.25-2.37)
NO₂ from 1991 onwards^b	1.13 (1.05-1.22)	1.21 (1.02-1.42)	1.13 (0.88-1.45)	0.99 (0.70-1.41)	1.56 (1.17-2.10)
NO₂ (1-year mean) at address at baseline^b	1.09 (1.01-1.19)	1.16 (0.99-1.37)	1.09 (0.85-1.41)	1.06 (0.75-1.52)	1.42 (1.06-1.92)
Major road within 50 of address at baseline	0.94 (0.85-1.05)	0.98 (0.79-1.21)	1.04 (0.76-1.44)	0.87 (0.54-1.39)	1.03 (0.71-1.49)
Traffic load within 200 m of address at baseline^c	1.01 (0.99-1.03)	1.02 (0.98-1.06)	1.01 (0.95-1.07)	1.02 (0.94-1.11)	1.03 (0.96-1.11)

Results based on 677 761 person–years at risk for 52 061 cohort participants from baseline (1993–1997) through 2009.
^aAdjusted for sex, age (age was the time scale), calendar year, employment status, school attendance, occupation with potential exposure to smoke and fumes, smoking status, smoking intensity, smoking duration, environmental tobacco smoke, alcohol, fat, fish, fruit and vegetables, fiber, folate, body mass index, waist circumference, physical activity with sport, hormone replacement therapy, average gross income of municipality of residence in 1995 and noise at the baseline address. The Cox model stratified for marital status.
^bThe mortality rate ratio is given per doubling of the NO₂ concentration. The three NO₂ measures correlated strongly; r_s = 0.92 between NO₂ from1971 and NO₂ from 1991; r_s = 0.87 between NO₂ from1971 and NO₂ at baseline; r_s = 0.95 between NO₂ from1991 and NO₂ at baseline.
^cThe mortality rate ratio is given per doubling of the traffic load.

ISSN: 1476-069X