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

<div><p>Background</p><p>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.</p><p>Methods and materials</p><p>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.</p><p>Results</p><p>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.</p><p>Conclusion</p><p>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.</p></div

Flow-chart of the study population.

<p>Flow-chart of the study population.</p

Sensitivity analyses of the association between road traffic noise (per 10 dB) over entire follow-up period, and risk of overall mortality.

<p>Sensitivity analyses of the association between road traffic noise (per 10 dB) over entire follow-up period, and risk of overall mortality.</p

Characteristics of persons diagnosed with colorectal cancer in the Danish Diet, Cancer and Health cohort.

<p>All colorectal cancer caser patients, those who died during follow-up (All-cause mortality), and those who died from colorectal cancer (Colorectal cancer-specific mortality). Median and 5–95 percentile, unless otherwise stated.</p

Crude and adjusted associations between residential road traffic noise exposure (L_den) and overall and colorectal-cancer specific mortality, linear estimates per 10 dB.

<p>Crude and adjusted associations between residential road traffic noise exposure (L_den) and overall and colorectal-cancer specific mortality, linear estimates per 10 dB.</p

Characteristics of the DCH cohort at time of follow-up by Physical Component Summary (PCS) and Mental Component Summary (MCS) score.

<p>^a Percentages or Median (5–95% CI)</p><p>^b Among those drinking alcohol</p><p>Characteristics of the DCH cohort at time of follow-up by Physical Component Summary (PCS) and Mental Component Summary (MCS) score.</p

Crude and adjusted associations between residential road traffic noise exposure (L_den) and SF-36 component summary scores, per 10 dB.

<p>^a Adjusted for age, sex</p><p>^b Adjusted for Model 1 plus education, cohabitance status, income and railway noise</p><p>^c Adjusted for Model 2 plus smoking status, waist circumference, and alcohol intake</p><p>Crude and adjusted associations between residential road traffic noise exposure (L_den) and SF-36 component summary scores, per 10 dB.</p

Association between residential exposure to road traffic noise 1 year before SF-36 and MCS score.

<p>Left: Model 2, right: Model 3. Development in MCS-score over the spectrum of road traffic noise exposure from 48 to 71 dB. X-aksis: Road traffic noise in dB, y-aksis: MCS-score. Solid line: Estimate. Grey lines: 95% CI.</p

Association between railway noise exposure at time of SF-36 and PCS/MCS.

<p>^aAdjusted for age, sex</p><p>^bAdjusted for Model 1plus education, cohabitance status, income and railway noise</p><p>^cAdjusted for Model 2 plus smoking status, waist circumference, and alcohol intake</p><p>We investigated effect modification for MSC and PSC by sex, age, education, Charlson Comorbidity Index, and train noise exposure, but found no significant interactions (all p ≥ 0.14, results not shown).</p><p>Association between railway noise exposure at time of SF-36 and PCS/MCS.</p

Residential traffic noise exposure and vestibular schwannoma – a Danish case–control study

<p><b>Background:</b> Few risk factors for sporadic vestibular schwannoma (VS) are known. Several studies have proposed an increased risk with occupational noise exposure, whereas no studies have investigated residential traffic noise exposure as a risk factor. The present study investigated if residential traffic noise was associated with vestibular schwannoma in a large, population-based Danish case–control study.</p> <p><b>Material and methods:</b> We identified 1454 VS cases, age above 30 years at diagnosis, between 1990 and 2007. For each case, we selected two random population controls, matched on sex and year of birth. Road and railway traffic noise at the residence was calculated for all present and historical addresses between 1987 and index date. Associations between traffic noise and risk for VS were estimated using conditional logistic regression, adjusted for education, disposable personal income, cohabitation status, railway noise exposure, municipal population density, and municipal income.</p> <p><b>Results:</b> A two-year time-weighted mean road traffic noise exposure was associated with an adjusted odds ratio of 0.92 (0.82–1.03) for developing VS, per 10 dB increment. There was no clear trend in categorical analyses. Similarly, linear and categorical analyses of residential railway noise did not suggest an association. We found no interaction with demographics, year of diagnosis, individual and municipal socioeconomic variables, and railway noise exposure. The results did not differ by tumor side, spread or size.</p> <p><b>Conclusions:</b> The present study does not suggest an association between residential traffic noise and VS.</p