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Cardiovascular effects of diesel exhaust and ozone in a multi-pollutant context
Stevens, T., M. Case, A. Rappold, J. Pleil, D. Diaz-Sanchez, W. Cascio, R. Devlin, AND M. Madden. Cardiovascular effects of diesel exhaust and ozone in a multi-pollutant context. Presented at Society of Toxicology, Phoenix, AZ, March 23 - 27, 2014.
The cardiovascular effects of two common pollutants, diesel exhaust (DE) and ozone (O3), were examined alone and in combination. Healthy subjects (n=15) were exposed for 2 hrs with intermittent, moderate exercise on Day 1 to 0.3 ppm O3, 300 µg/m3 DE, both O3 and DE, or filtered air (FA). On Day 2, subjects were exposed to 0.3 ppm O3. Cardiac electrophysiology and venipuncture were performed pre and post exposure. In addition, blood pressure (BP) was measured pre, post, and every hour up through 4 hrs post on days 1 and 2. Relative to air exposure values, maximum heart rate decreased ~12% immediately post DE exposure, and the cardiac QTc interval (QTcDYN) increased ~2% immediately post O3 and DE+O3 exposure. Systolic BP was significantly decreased immediately post DE+O3 exposure compared to air. Plasma lipid profiles were altered significantly immediately after day 1 exposure. Specifically, after DE+O3 exposure triglycerides were decreased (vs O3), and VLDL decreased compared to O3 and DE. LDL and HDL levels increased compared to O3 and air, respectively. Evidence was found for independent effects of acute O3 and DE exposures alone and in combination on some outcomes. These data suggest that either interactions of ambient air pollutants or individual pollutants themselves may play a role in inducing adverse health outcomes. [Disclaimer: The views expressed are those of the authors and do not necessarily reflect the official views or policies of the US EPA.]
Key Research Question(s) Being Addressed: 1; Do interactions occur among components of a multipollutant mixture that are non-additive; i.e. synergistic? 2; What are the contributions of mixture components to heath effects caused by an air pollutant mixture? 3; Are there populations at risk for exposure to air pollutant mixtures that differ from those at risk for exposure to single pollutants? The fundamental issue that underlies assessing health effects associated with exposure to multipollutant mixtures is the concern that interactions occur among mixture components such that the effects of the mixture are non-additive (i.e. synergistic).
Record Details:Record Type: DOCUMENT (PRESENTATION/ABSTRACT)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB
ENVIRONMENTAL PUBLIC HEALTH DIVISION
CLINICAL RESEARCH BRANCH