Long- and Short-Term Air Pollution Exposure and Markers of Inflammation and Coagulation in a Population Sample from Stockholm

Abstract

ISEE-0408 Background and Objective: Exposure to elevated levels of ambient air pollutants can cause adverse cardiovascular effects through systemic inflammation and changes in coagulation balance. We aimed 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 of relevance for cardiovascular pathology. Methods: We studied a population sample of 1028 men and 508 women aged 45 to 70 years from Stockholm, Sweden. Data on cardiovascular risk factors were collected from questionnaires. Blood samples were collected at medical examinations. 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 to 120 hours before blood sampling. Results: Long-term exposures to both traffic-NO2 and heating-SO2 emissions showed a consistent association with elevated IL-6 levels. 30-year average traffic-NO2 exposure was associated with 64.5% (95%CI 6.7–153.8%) increase in serum IL-6 per 28.8 μg/m3 (corresponding to the difference between the 5th and the 95th percentile exposure value), and 30-year exposure to heating-SO2 with 67.6% (95%CI 7.1–162.2%) increase per 39.4 μg/m3 (5th–95th percentile value difference). The association appeared stronger in non-smokers, physically active people, and hypertensive persons. We observed positive non-significant associations of inflammatory markers with NO2 and PM10 during 24 hours before blood sampling. Conclusion: Our results suggest that exposure to moderate levels of air pollution may influence serum levels of inflammatory markers.