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Inhalation of diesel exhaust induces acute arterial vasocontruction in healthy volunteers
Citation:
TONG, H., M. BASSETT, D. GRAFF, A. Hinderliter, M. Schmitt, R. B. DEVLIN, AND J. M. SAMET. Inhalation of diesel exhaust induces acute arterial vasocontruction in healthy volunteers. Presented at American Thoracic Society Annual Meeting, San Diego, CA, May 15 - 20, 2008.
Impact/Purpose:
research results
Description:
Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust particles (DE) are a major contributor to PM in urban areas. Advanced age and certain polymorphisms are among the susceptibility factors implicated in the effects of PM. In order to investigate the cardiopulmonary effects of short-term exposure to DE in healthy older subjects, each of 6 subjects of GSTM1 null genotype underwent three 2-hr exposures to DE sampled in real time from the exhaust of an idling diesel truck engine. The exposures were incrementally increased from100 ug/m3 to 200 ug/m3, and 300 ug/m3 and were conducted at least 14 days apart. Before and after each exposure, brachial artery diameter (BAD) and endothelium-dependent and –independent flow-mediated dilation (FMD) were assessed by ultrasound imaging. Blood pressure was monitored every 15 min during exposure. Indices of pulmonary function as well as inflammation and coagulation markers in the blood were also evaluated. We report that exposure to 300 ug/m3 DE resulted in a statistically significant reduction of baseline BAD (3.34±0.27 mm pre- vs. 3.23±0.26 mm post-exposure; p<0.05). Exposure to lower doses of DE did not cause significant changes on BAD. There were no consistent alterations of FMD, blood pressure, pulmonary function or blood markers. This study demonstrates that short-term exposure to DE induces acute arterial vasoconstriction. This finding suggests that arterial vasoconstriction may be one mechanism by which traffic-related air pollution contributes to cardiovascular risk in susceptible populations. THIS ABSTRACT OF A PROPOSED PRESENTATION DOES NOT NECESSARILY REFLECT EPA POLICY.