Table 2.

Exposure to traffic noise and air pollution during 5 y prior to study baseline in nine cohorts from Scandinavia.

Characteristicsa	Copenhagen or Aarhus, DK	Denmark	Malmö, SE	Gothenburg, SE		Stockholm, SE
	DCH	DNC	MDC	PPS	GOT-MONICA	SDPP	SIXTY	SNAC-K	SALT	Total
NordSOUND baseline	1993–1997	1993, 1999	1991–1996	1975	1985, 1990, 1995	1992–1998	1997–1999	2001–2004	1998–2002	1975–2002
Road traffic noise [5 y at 40 dB ${\mathrm{L}}_{\text{den}}$ and above (%)]	52,517 (99.2)	24,902 (95.3)	25,719 (96.8)	5,145 (98.3)	2,184 (94.6)	3,845 (51.0)	2,842 (75.4)	2,182 (96.9)	4,595 (75.9)	123,931 (93.3)
Road traffic noisea [5 y (dB ${\mathrm{L}}_{\text{den}}$)]	56.6 (45.0–69.4)	53.6 (40.2–66.9)	54.6 (42.4–67.5)	57.5 (45.4–72.4)	56.1 (40.0–69.2)	40.2 (40.0–54.2)	46.6 (40.0–62.7)	58.3 (44.8–68.2)	47.3 (40.0–63.3)	54.5 (40.0–68.1)
Railway noise at 40 dB ${\mathrm{L}}_{\text{den}}$ and above (%)	13,638 (25.8)	5,008 (19.2)	7,438 (28.0)	788 (15.1)	460 (19.9)	1,093 (14.5)	1,196 (31.7)	1,170 (52.0)	2,063 (34.1)	32,854 (24.7)
Railway noisea,b [5 y (dB ${\mathrm{L}}_{\text{den}}$)]	52.3 (42.1–66.6)	52.9 (41.8–65.9)	46.8 (40.6–67.7)	44.8 (40.4–58.8)	44.6 (40.3–57.7)	50.5 (42.2–67.3)	48.9 (40.8–63.6)	49.1 (41.6–59.5)	49.2 (40.7–64.1)	50.5 (41.0–66.0)
Aircraft noise at baselinec [5 y (%)]
$\le 40$ dB ${\mathrm{L}}_{\text{den}}$	52,215 (98.6)	25,816 (98.8)	—c	—	—	5,638 (74.8)	3,146 (83.5)	364 (16.1)	5,037 (83.2)	126,333 (95.1)
40.1–50 dB ${\mathrm{L}}_{\text{den}}$	351 (0.7)	102 (0.4)	—	—	—	720 (9.6)	510 (13.5)	1,472 (65.4)	820 (13.5)	3,975 (3.0)
$>50$ dB ${\mathrm{L}}_{\text{den}}$	382 (0.7)	208 (0.8)	—	—	—	1,176 (15.6)	114 (3.0)	416 (18.6)	197 (3.3)	2,493 (1.9)
${\mathrm{PM}}_{2.5}$a,d,e [5 y (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)]	19.2 (18.5–24.0)	20.7d (15.3–26.2)	11.0 (9.7–12.4)	9.7e (6.4–12.2)	9.9 (8.0–11.9)	7.6 (6.7–8.4)	8.0 (6.8–9.5)	8.3 (7.7–10.3)	7.7 (6.4–9.3)	18.7 (7.4–24.1)
${\mathrm{NO}}_2$a,d,e [5 y (${\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)]	27.5 (19.6–46.5)	10.8d (5.6–28.0)	24.2 (13.7–34.9)	30.7e (22.9–43.5)	27.5 (18.4–42.4)	8.6 (4.9–13.9)	13.0 (5.3–26.2)	20.5 (15.0–32.2)	13.1 (5.5–25.6)	23.9 (7.0–40.7)

Note: —, no data; dB, decibel; DK, Denmark; DCH, the Danish Diet Cancer and Health cohort; DNC, the Danish Nurse Cohort; GOT-MONICA, the Gothenburg cohort of “Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases” (MONICA) project, Sweden; ${\mathrm{L}}_{\text{den}}$, day-evening-night noise level based on energy equivalent noise level over a whole day with a penalty of 10 dB for nighttime noise (23.00–7.00) and a penalty of 5 dB for evening noise (i.e., 19.00–23.00); MDC, the Malmö Diet and Cancer cohort, Sweden; ${\mathrm{PM}}_{2.5}$, particulate matter with an aerodynamic diameter of $\le \mathrm{2.5\hspace{0.17em}}\mathrm{\mu }\mathrm{m}$ (fine particulate matter); PPS, the Primary Prevention Study cohort, Gothenburg, Sweden; ${\mathrm{NO}}_2$, nitrogen dioxide; SDPP, the Stockholm Diabetes Preventive Program, Sweden; SE, Sweden; SIXTY, the 60-Years Cohort, Stockholm, Sweden; SNAC-K, the Swedish National Study of Aging and Care in Kungsholmen, Stockholm, Sweden.

^a Median and 5th–95th percentiles, unless otherwise stated.

^b Calculated among those with railway noise exposure at 40 dB ${\mathrm{L}}_{\text{den}}$ and above.

^c Only among cohorts with aircraft noise exposure (thus excluding MDC, PPS, and GOT-MONICA).

^d Data on exposure to ${\mathrm{PM}}_{2.5}$ and ${\mathrm{NO}}_2$ missing for 9.2% in DNC.

^e Data on exposure to ${\mathrm{PM}}_{2.5}$ and ${\mathrm{NO}}_2$ missing for 99.1% and 2.7%, respectively, in the PPS cohort. The high fraction of missing values for ${\mathrm{PM}}_{2.5}$ is explained by recruitment in 1970–1973 and start of ${\mathrm{PM}}_{2.5}$ modeling in 1990 (see Tables S1 and S3).