In-traffic air pollution exposure and CC16, blood coagulation, and inflammation markers in healthy adults

BACKGROUND: Exposure to traffic-related air pollution is a risk factor for cardiovascular events, probably involving mechanisms of inflammation and coagulation. Little is known about effects of the short exposures encountered while participating in traffic. OBJECTIVES: The objective of the study was to examine effects of exposure of commuters to air pollution on cardiovascular biomarkers. METHODS: Thirty-four healthy adult volunteers commuted for 2 hr by bus, car, or bicycle during the morning rush hour. During the commute, exposure to particle number, particulate matter (PM) = 2.5 µm in aerodynamic diameter (PM2.5), PM = 10 µm in diameter (PM10), and soot was measured. We estimated inhaled doses based on heart rate monitoring. Shortly before exposure and 6 hr after exposure, blood samples were taken and analyzed for CC16 (Clara cell protein 16), blood cell count, coagulation markers, and inflammation markers. Between June 2007 and June 2008, 352 pre- and postexposure blood samples were collected on 47 test days. We used mixed models to analyze the associations between exposure and changes in health parameters. RESULTS: We observed no consistent associations between the air pollution exposures and doses and the various biomarkers that we investigated. CONCLUSIONS: Air pollution exposure during commuting was not consistently associated with acute changes in inflammation markers, blood cell counts, or blood coagulation markers.