title: Modeling population exposure to community noise and air pollution in a large metropolitan area.
abstract: Epidemiologic studies have shown that both air pollution and community noise are associated with cardiovascular disease mortality. Because road traffic is a major contributor to these environmental pollutants in metropolitan areas, it is plausible that the observed associations may be confounded by coexistent pollutants. As part of a large population-based cohort study to address this concern, we used a noise prediction model to assess annual average community noise levels from transportation sources in metropolitan Vancouver, Canada. The modeled annual average noise level was 64 (inter quartile range 60-68) dB(A) for the region. This model was evaluated by comparing modeled annual daytime A-weighted equivalent continuous noise levels (L(day)) with measured 5-min daytime A-weighted equivalent continuous noise levels (L(eq,day,5 min)) at 103 selected roadside sites in the study region. On average, L(day) was 6.2 (95% CI, 6.0-7.9) dB(A) higher than, but highly correlated (r=0.62; 95% CI, 0.48-0.72) with, L(eq,day,5 min). These results suggest that our model-based noise exposure assessment could approximately reflect actual noise exposure in the study region. Overall, modeled noise levels were not strongly correlated with land use regression estimates of traffic-related air pollutants including black carbon, particulate matter with aerodynamic diameter ≤2.5 μm (PM(2.5)), NO(2) and NO; the highest correlation was with black carbon (r=0.48), whereas the lowest correlation was with PM(2.5) (r=0.18). There was no consistent effect of traffic proximity on the correlations between community noise levels and traffic-related air pollutant concentrations. These results, consistent with previous studies, suggest that it is possible to assess potential adverse cardiovascular effects from long-term exposures to community noise and traffic-related air pollution in prospective epidemiologic studies.
authors.affiliation: School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Wen Qi
authors.initials: WQ
authors.lastname: Gan
authors.forename: Kathleen
authors.initials: K
authors.lastname: McLean
authors.forename: Michael
authors.initials: M
authors.lastname: Brauer
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Chiarello
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Davies
mesh_terms: D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis*; D001955:British Columbia; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology; D002947:Cities; D003198:Computer Simulation; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D006801:Humans; D008962:Models, Theoretical; D009624:Noise, Transportation / Q000009:adverse effects*; D014505:Urban Population; D014507:Urbanization