Article Text
Abstract
Background: Exposure to elevated levels of ambient air pollutants can lead to adverse cardiovascular effects. Potential mechanisms include systemic inflammation and perturbation of the coagulation balance.
Objectives: To investigate long- and short-term effects of air pollution exposure on serum levels of inflammatory (IL-6, TNF-α and CRP) and coagulation (fibrinogen and PAI-1) markers relevant for cardiovascular pathology.
Methods: The study group consisted of a population sample of 1028 men and 508 women aged 45–70 years from Stockholm. Long-term air pollution exposure was assessed using spatial modelling of traffic-related NO2 and heating-related SO2 emissions at each subject’s residential addresses over retrospective periods of 1, 5 and 30 years. Short-term exposure was assessed as averages of rooftop measurements over 12–120 h before blood sampling.
Results: Long-term exposures to both traffic-NO2 and heating-SO2 emissions showed consistent associations with IL-6 levels. 30-year average traffic-NO2 exposure was associated with a 64.5% (95% CI 6.7% to 153.8%) increase in serum IL-6 per 28.8 μg/m3 (corresponding to the difference between the 5th and 95th percentile exposure value), and 30-year exposure to heating-SO2 with a 67.6% (95% CI 7.1% to 162.2%) increase per 39.4 μg/m3 (5th–95th percentile value difference). The association appeared stronger in non-smokers, physically active people and hypertensive subjects. We observed positive non-significant associations of inflammatory markers with NO2 and PM10 during 24 h before blood sampling. Short-term exposure to O3 was associated with increased, and SO2 with decreased, fibrinogen levels.
Conclusions: Our results suggest that exposure to moderate levels of air pollution may influence serum levels of inflammatory markers.
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Footnotes
Additional tables are published online only at http://oem.bmj.com/content/vol66/issue11
Funding The research was supported by the Swedish Medical Research Council (09533), the Swedish Lung and Heart Foundation, and King Gustaf the V and Queen Victoria’s Foundation.
Competing interests FN is employed by AstraZeneca and AstraZeneca also supports his academic part-time adjunct position as Lecturer in Molecular Epidemiology at Karolinska Institutet. FN also holds some AstraZeneca shares. MR is currently employed by GlaxoSmithKline Biologicals.
Ethics approval The study was approved by the Ethics Committee at Karolinska Institutet.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.