Background: There is growing evidence that air pollution from traffic has adverse long-term effects on chronic respiratory disease in children, but there are few studies and more inconclusive results in adults. We examined associations between residential traffic and asthma and COPD in adults in southern Sweden. A postal questionnaire in 2000 (n = 9319, 18-77 years) provided disease status, and self-reported exposure to traffic. A Geographical Information System (GIS) was used to link geocoded residential addresses to a Swedish road database and an emission database for NOx.

BackgroundResults from studies of road traffic noise and hypertension are heterogeneous with respect to effect size, effects among males and females and with respect to effects across age groups. Our objective was to further explore these associations.MethodsThe study used cross-sectional public health survey data from southern Sweden, including 24,238 adults (18 - 80 years old). We used a geographic information system (GIS) to assess the average road noise (LAeq 24 hr) at the current residential address. Effects on self-reported hypertension were estimated by logistic regression with adjustment for age, sex, BMI, alcohol intake, exercise, education, smoking and socioeconomic status.ResultsModest exposure effects (OR ≈ 1.1) were generally noted in intermediate exposure categories (45 -64 dB(A)), and with no obvious trend. The effect was more pronounced at > 64 dB(A) (OR 1.45, 95% CI 1.04 - 2.02). Age modified the relative effect (p = 0.018). An effect was seen among middle-aged (40 - 59 years old) at noise levels 60 - 64 dB(A) (OR = 1.27, 95% CI 1.02 - 1.58)) and at > 64 dB(A) (OR = 1.91, 95% CI 1.19 - 3.06)). An effect was also indicated among younger adults but not among elderly. No apparent effect modification by gender, country of origin, disturbed sleep or strained economy was noted.ConclusionThe study supports an association between road traffic noise at high average levels and self-reported hypertension in middle-aged. Future studies should use age group -specific relative effect models to account for differences in prevalence.

Background: There is conflicting evidence that traffic-related air pollution is a risk factor for allergic conditions. Few studies have investigated this in adults. In adults, a high proportion of asthma, rhinitis and eczema is triggered by non-allergic factors. We investigated traffic as a risk factor for allergic versus non-allergic asthma and rhinitis, and eczema, in adults.

Background: Short-term exposure to high levels of air pollution can increase stroke risk. In this study we investigated the short-term effects of air pollution on hospital admissions for stroke in a setting where pollutant levels are rather low. We also addressed methodological issues in evaluating the short-term effects of air pollution. Methods: Daily admissions of ischemic (n = 11,267) and hemorrhagic (n = 1,681) stroke were obtained from a Swedish quality register for stroke, Riks-Stroke. We used two types of exposure data: (1) daily measured background levels of ozone, temperature and particles with a diameter <10 µm (PM₁₀) and (2) modeled levels of a mixture of NO and NO₂ (NO_x) at the residential address of each individual. Results: We estimated a 13% (95% confidence interval, 4–22%) increased risk for hospital admissions for ischemic stroke for levels of PM₁₀ above 30 µg/m³ compared to <15 µg/m³, whereas temperature above 16°C decreased the risk. No consistent associations were found for hemorrhagic stroke or for ischemic stroke and ozone or NO_x. Conclusion: Particulate air pollution and temperature seemed to be associated with ischemic stroke hospital admissions. Individual exposure modeling facilitates a detailed exposure assessment but may also be more prone to misclassification errors. The time series and case crossover approaches yielded similar effect estimates.

BackgroundThe knowledge about air pollution effects on birth weight, prematurity, and small for gestational age (SGA) in low-exposure areas is insufficient.ObjectivesThe aim of this birth cohort study was to investigate whether low-level exposure to air pollution was associated with prematurity and fetal growth and whether there are sex-specific effects.MethodWe combined high-quality registry information on 81,110 births with individually modeled exposure data at residence for nitrogen oxides (NOx) and proximity to roads with differing traffic density. The data were analyzed by logistic and linear regression with and without potential confounders.ResultsWe observed an increased risk for babies being SGA when we compared highest and lowest NOx quartiles, adjusting for maternal age, smoking, sex, and year of birth. After additional adjustment for maternal country of origin and parity (which were highly intercorrelated), the increase was no longer statistically significant. However, in subgroup analyses when we compared highest and lowest NOx quartiles we still observed an increased risk for SGA for girls [odds ratio (OR) = 1.12; 95% confidence interval (CI), 1.01–1.24); we also observed increased risk among mothers who had not changed residency during pregnancy (OR = 1.09; 95% CI, 1.01–1.18). The confounders with the greatest impact on SGA were parity and country of origin. Concerning prematurity, the prevalence was lower in the three higher NOx exposure quartiles compared with the lowest category.ConclusionFor future studies on air pollution effects on birth outcomes, careful control of confounding is crucial.