Long-Term Exposure to Transportation Noise and Ischemic Heart Disease: A Pooled Analysis of Nine Scandinavian Cohorts.

BACKGROUND: Transportation noise may induce cardiovascular disease, but the public health implications are unclear. OBJECTIVES: The study aimed to assess exposure-response relationships for different transportation noise sources and ischemic heart disease (IHD), including subtypes. METHODS: Pooled analyses were performed of nine cohorts from Denmark and Sweden, together including 132,801 subjects. Time-weighted long-term exposure to road, railway, and aircraft noise, as well as air pollution, was estimated based on residential histories. Hazard ratios (HRs) were calculated using Cox proportional hazards models following adjustment for lifestyle and socioeconomic risk factors. RESULTS: A total of 22,459 incident cases of IHD were identified during follow-up from national patient and mortality registers, including 7,682 cases of myocardial infarction. The adjusted HR for IHD was 1.03 [95% confidence interval (CI) 1.00, 1.05] per 10 dB Lden for both road and railway noise exposure during 5 y prior to the event. Higher risks were indicated for IHD excluding angina pectoris cases, with HRs of 1.06 (95% CI: 1.03, 1.08) and 1.05 (95% CI: 1.01, 1.08) per 10 dB Lden for road and railway noise, respectively. Corresponding HRs for myocardial infarction were 1.02 (95% CI: 0.99, 1.05) and 1.04 (95% CI: 0.99, 1.08). Increased risks were observed for aircraft noise but without clear exposure-response relations. A threshold at around 55 dB Lden was suggested in the exposure-response relation for road traffic noise and IHD. DISCUSSION: Exposure to road, railway, and aircraft noise in the prior 5 y was associated with an increased risk of IHD, particularly after exclusion of angina pectoris cases, which are less well identified in the registries. https://doi.org/10.1289/EHP10745.

Long-term exposure to air pollution and stroke incidence: A Danish Nurse cohort study.

Ambient air pollution has been linked to stroke, but few studies have examined in detail stroke subtypes and confounding by road traffic noise, which was recently associated with stroke. Here we examined the association between long-term exposure to air pollution and incidence of stroke (overall, ischemic, hemorrhagic), adjusting for road traffic noise. In a nationwide Danish Nurse Cohort consisting of 23,423 nurses, recruited in 1993 or 1999, we identified 1,078 incident cases of stroke (944 ischemic and 134 hemorrhagic) up to December 31, 2014, defined as first-ever hospital contact. The full residential address histories since 1970 were obtained for each participant and the annual means of air pollutants (particulate matter with diameter < 2.5 µm and < 10 µm (PM2.5 and PM10), nitrogen dioxide (NO2), nitrogen oxides (NOx)) and road traffic noise were determined using validated models. Time-varying Cox regression models were used to estimate hazard ratios (HR) (95% confidence intervals (CI)) for the associations of one-, three, and 23-year running mean of air pollutants with stroke adjusting for potential confounders and noise. In fully adjusted models, the HRs (95% CI) per interquartile range increase in one-year running mean of PM2.5 and overall, ischemic, and hemorrhagic stroke were 1.12 (1.01-1.25), 1.13 (1.01-1.26), and 1.07 (0.80-1.44), respectively, and remained unchanged after adjustment for noise. Long-term exposure to ambient PM2.5 was associated with the risk of stroke independent of road traffic noise.

Residential road traffic noise exposure and colorectal cancer survival - A Danish cohort study.

BACKGROUND: Residential traffic noise exposure may entail sleep disruption and compromised circadian functioning; two factors which have been associated with a poor colorectal cancer (CRC) prognosis. Hence, the aim of the present study was to investigate the association between residential road traffic noise and CRC survival. METHODS AND MATERIALS: Road traffic noise was calculated for all residential addresses from 1987 to February 2012 for incident CRC cases (n = 1,234) in a cohort of 57,053 Danes. We used Cox Proportional Hazard Models to investigate the association between residential road traffic noise at different time-windows, and overall and CRC-specific mortality. Furthermore, we investigated interaction with sex, age, prognostic factors, and comorbidity. Mortality Rate Ratios (MRR) were calculated in unadjusted models, and adjusted for railway noise, lifestyle factors, and socioeconomic variables. RESULTS: During a median follow-up of 4 years, 594 patients died; 447 from CRC. We found no association between road traffic noise exposure and overall (MRR 1.00 (0.88-1.13) per 10 dB) or CRC-specific mortality (MRR 0.98 (0.85-1.13) per 10 dB) over the entire follow-up period, or 1 year preceding death. Results did not differ when examining colon and rectal cancer separately. Interaction analyses suggested that patients with less clinically advanced disease could be more susceptible to harmful effects of traffic noise. CONCLUSION: The present study suggests no overall association between residential road traffic noise and concurrent mortality in CRC patients. As it is the first study of its kind, with relatively limited power, further studies are warranted.