Table 2.

Associations between long-term exposure to air pollution (per IQR exposure increment) and both overall and fatal incident MI in the Danish Nurse Cohort.

Pollutants	Overall incident MI			Fatal incident MI
	Model 1a	Model 2b	Model 3c	Model 1a	Model 2b	Model 3c
	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)	HR (95% CI)
1-y mean
$n$ (cases)	22,884 (641)	22,884 (641)	22,878 (641)	22,955 (123)	22,955 (123)	22,878 (121)
${\mathrm{PM}}_{2.5}$	1.17 (1.05, 1.31)	1.05 (0.92, 1.19)	1.04 (0.91, 1.19)	1.75 (1.40, 2.18)	1.47 (1.12, 1.93)	1.48 (1.13, 1.95)
${\mathrm{PM}}_{10}$	1.19 (1.07, 1.31)	1.04 (0.92, 1.17)	1.04 (0.92, 1.17)	1.75 (1.44, 2.13)	1.43 (1.12, 1.81)	1.45 (1.14, 1.84)
${\mathrm{NO}}_2$	1.03 (0.95, 1.13)	1.04 (0.94, 1.16)	1.04 (0.93, 1.17)	1.04 (0.86, 1.26)	1.05 (0.83, 1.31)	1.08 (0.85, 1.38)
${\mathrm{NO}}_{\mathrm{x}}$	1.03 (0.98, 1.07)	1.02 (0.97, 1.07)	1.02 (0.97, 1.08)	1.03 (0.93, 1.14)	1.02 (0.91, 1.13)	1.03 (0.92, 1.15)
3-y mean
$n$ (cases)	22,887 (641)	22,887 (641)	22,882 (641)	22,887 (121)	22,887 (121)	22,882 (121)
${\mathrm{PM}}_{2.5}$	1.20 (1.07, 1.35)	1.06 (0.92, 1.23)	1.06 (0.92, 1.23)	1.69 (1.33, 2.13)	1.35 (1.01, 1.81)	1.38 (1.03, 1.85)
${\mathrm{PM}}_{10}$	1.22 (1.09, 1.35)	1.06 (0.93, 1.21)	1.06 (0.93, 1.20)	1.65 (1.34, 2.03)	1.28 (0.98, 1.65)	1.29 (0.99, 1.68)
${\mathrm{NO}}_2$	1.04 (0.95, 1.13)	1.05 (0.94, 1.16)	1.05 (0.94, 1.17)	1.02 (0.84, 1.23)	1.01 (0.80, 1.28)	1.05 (0.81, 1.34)
${\mathrm{NO}}_{\mathrm{x}}$	1.03 (0.98, 1.07)	1.02 (0.98, 1.07)	1.02 (0.97, 1.08)	1.02 (0.92, 1.13)	1.01 (0.90, 1.12)	1.02 (0.91, 1.14)
23-y mean
$n$ (cases)	22,902 (642)	22,902 (642)	22,902 (642)	22,902 (121)	22,902 (121)	22,902 (121)
${\mathrm{NO}}_2$	1.04 (0.96, 1.13)	1.10 (0.99, 1.22)	1.13 (1.01, 1.27)	1.01 (0.84, 1.22)	1.08 (0.86, 1.36)	1.12 (0.87, 1.43)
${\mathrm{NO}}_{\mathrm{x}}$	1.03 (1.00, 1.07)	1.04 (1.00, 1.08)	1.05 (1.00, 1.09)	1.02 (0.94, 1.11)	1.03 (0.94, 1.12)	1.04 (0.94, 1.14)

Note: Estimates are based on IQR increments for ${\mathrm{PM}}_{2.5}$ ($<5.3\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$), ${\mathrm{PM}}_{10}$ ($<5.5\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$), ${\mathrm{NO}}_2$ ($<8.1\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$), and ${\mathrm{NO}}_{\mathrm{x}}$ ($<11.5\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$), and ${\mathrm{L}}_{\text{den}}$ ($10\text{dB}$). CI, confidence interval; HR, hazard ratio; IQR, interquartile range; ${\mathrm{L}}_{\mathrm{den}}$, joint expression of day (${\mathrm{L}}_{\mathrm{d}}$; 0700–1900 hours), evening (${\mathrm{L}}_{\mathrm{e}}$; 1900–2200 hours), and night (${\mathrm{L}}_{\mathrm{n}}$; 2200–0700 hours) road traffic noise levels, with 5 and $10\text{dB}$ penalties added to ${\mathrm{L}}_{\mathrm{e}}$ and ${\mathrm{L}}_{\mathrm{n}}$, respectively; MI, myocardial infarction; ${\mathrm{NO}}_2$, nitrogen dioxide; ${\mathrm{NO}}_{\mathrm{x}}$, nitrogen oxides; PM, particulate matter; ${\mathrm{PM}}_{2.5}$, PM with an aerodynamic diameter of $<2.5\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$; ${\mathrm{PM}}_{10}$, PM with an aerodynamic diameter of $<10\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$.

^aModel 1: adjusted for age (underlying time) and year of cohort entry (1993 or 1999).

^bModel 2: Model 1 further adjusted for smoking status, pack-years, consumption of fruit, avoidance of fatty meat, alcohol consumption, use of oral contraceptives, use of hormone therapy, physical activity, marital status, employment status, and level of urbanization.

^cModel 3: Model 2 further adjusted for ${\mathrm{L}}_{\text{den}}$.