Traffic-generated air pollution and myocardial infarction.
ABSTRACT Although long-term air pollution exposure has been linked to cardiovascular mortality, data on incidence and nonfatal coronary disease are limited and inconclusive. The aim of this study was to investigate the association between long-term residential exposure to air pollution from traffic and the risk of nonfatal and fatal myocardial infarction.
The records of all individuals aged 15 to 79 with a first event of myocardial infarction in Stockholm County during 1985 to 1996 were retrieved from a registry. Population controls were randomly selected from the study base stratified by age, sex, and calendar year. Individual socioeconomic data and home addresses were obtained from population censuses 1970 to 1995. Annual air pollution exposure was assessed by dispersion modeling at the home addresses of 24,347 cases and 276,926 controls.
Five-year average traffic-generated air pollution exposure corresponding to a difference in nitrogen dioxide from the fifth to the 95th percentile (31 microg/m) was associated with an odds ratio for fatal myocardial infarction adjusted for age, sex, calendar year, and socioeconomic status of 1.23 (95% confidence interval [CI] = 1.15-1.32). The corresponding odds ratio was 2.54 (1.96-3.29) among those with least expected misclassification of true individual exposure (those who did not move between censuses). Different time-windows and analyses of other pollutants including carbon monoxide and particles less than 10 mum in diameter (PM10) produced weaker associations. There was no increased risk for nonfatal myocardial infarction (ORs 0.94-0.98).
Long-term exposure to traffic-generated air pollution is associated with fatal myocardial infarction but not with nonfatal infarction.
Article: Individual exposure to NO2 in relation to spatial and temporal exposure indices in Stockholm, Sweden: the INDEX study.[show abstract] [hide abstract]
ABSTRACT: Epidemiology studies of health effects from air pollution, as well as impact assessments, typically rely on ambient monitoring data or modelled residential levels. The relationship between these and personal exposure is not clear. To investigate personal exposure to NO(2) and its relationship with other exposure metrics and time-activity patterns in a randomly selected sample of healthy working adults (20-59 years) living and working in Stockholm. Personal exposure to NO(2) was measured with diffusive samplers in sample of 247 individuals. The 7-day average personal exposure was 14.3 µg/m(3) and 12.5 µg/m(3) for the study population and the inhabitants of Stockholm County, respectively. The personal exposure was significantly lower than the urban background level (20.3 µg/m(3)). In the univariate analyses the most influential determinants of individual exposure were long-term high-resolution dispersion-modelled levels of NO(2) outdoors at home and work, and concurrent NO(2) levels measured at a rural location, difference between those measured at an urban background and rural location and difference between those measured in busy street and at an urban background location, explaining 20, 16, 1, 2 and 4% (R(2)) of the 7-day personal NO(2) variation, respectively. A regression model including these variables explained 38% of the variation in personal NO(2) exposure. We found a small improvement by adding time-activity variables to the latter model (R(2) = 0.44). The results adds credibility primarily to long-term epidemiology studies that utilise long-term indices of NO(2) exposure at home or work, but also indicates that such studies may still suffer from exposure misclassification and dilution of any true effects. In contrast, urban background levels of NO(2) are poorly related to individual exposure.PLoS ONE 01/2012; 7(6):e39536. · 4.09 Impact Factor
Article: Changes in residential proximity to road traffic and the risk of death from coronary heart disease.[show abstract] [hide abstract]
ABSTRACT: Residential proximity to road traffic is associated with increased coronary heart disease (CHD) morbidity and mortality. It is unknown, however, whether changes in residential proximity to traffic could alter the risk of CHD mortality. We used a population-based cohort study with a 5-year exposure period and a 4-year follow-up period to explore the association between changes in residential proximity to road traffic and the risk of CHD mortality. The cohort comprised all residents aged 45-85 years who resided in metropolitan Vancouver during the exposure period and without known CHD at baseline (n = 450,283). Residential proximity to traffic was estimated using a geographic information system. CHD deaths during the follow-up period were identified using provincial death registration database. The data were analyzed using logistic regression. Compared with the subjects consistently living away from road traffic (>150 m from a highway or >50 m from a major road) during the 9-year study period, those consistently living close to traffic (<or=150 m from a highway or <or=50 m from a major road) had the greatest risk of CHD mortality (relative risk [RR] = 1.29 [95% confidence interval = 1.18-1.41]). By comparison, those who moved closer to traffic during the exposure period had less increased risk than those who were consistently exposed (1.20 [1.00-1.43]), and those who moved away from traffic had even less increase in the risk (1.14 [0.95-1.37]). All analyses were adjusted for baseline age, sex, pre-existing comorbidities (diabetes, chronic obstructive pulmonary disease, hypertensive heart disease), and neighborhood socioeconomic status. Living close to major roadways was associated with increased risk of coronary mortality, whereas moving away from major roadways was associated with decreased risk.Epidemiology (Cambridge, Mass.) 09/2010; 21(5):642-9. · 5.51 Impact Factor
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ABSTRACT: Myocardial infarction has been associated with both transportation noise and air pollution. We examined residential exposure to aircraft noise and mortality from myocardial infarction, taking air pollution into account. We analyzed the Swiss National Cohort, which includes geocoded information on residence. Exposure to aircraft noise and air pollution was determined based on geospatial noise and air-pollution (PM10) models and distance to major roads. We used Cox proportional hazard models, with age as the timescale. We compared the risk of death across categories of A-weighted sound pressure levels (dB(A)) and by duration of living in exposed corridors, adjusting for PM10 levels, distance to major roads, sex, education, and socioeconomic position of the municipality. We analyzed 4.6 million persons older than 30 years who were followed from near the end of 2000 through December 2005, including 15,532 deaths from myocardial infarction (ICD-10 codes I 21, I 22). Mortality increased with increasing level and duration of aircraft noise. The adjusted hazard ratio comparing ≥60 dB(A) with <45 dB(A) was 1.3 (95% confidence interval = 0.96-1.7) overall, and 1.5 (1.0-2.2) in persons who had lived at the same place for at least 15 years. None of the other endpoints (mortality from all causes, all circulatory disease, cerebrovascular disease, stroke, and lung cancer) was associated with aircraft noise. Aircraft noise was associated with mortality from myocardial infarction, with a dose-response relationship for level and duration of exposure. The association does not appear to be explained by exposure to particulate matter air pollution, education, or socioeconomic status of the municipality.Epidemiology (Cambridge, Mass.) 09/2010; 21(6):829-36. · 5.51 Impact Factor