ARB Research Seminar

This page updated June 19, 2013

Cardiovascular Response to Freeway Air: Results of an On-Road Exposure Study

William C. Hinds, Sc.D., School of Public Health, University of California, Los Angeles

January 12, 2010
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Press Release
Research Project


This seminar summarizes a 24-month study of human response to two-hour exposures to freeway air in Southern California. A nine-passenger van was modified with a high-efficiency filtration system that delivered filtered or unfiltered air to an exposure chamber inside the van. State-of-the-art instruments were used to measure concentration and size distribution of fine and ultrafine particles and the concentration of other pollutants associated with motor vehicles. Nineteen volunteer subjects (average age 71 years) rode for two hours each in filtered and unfiltered air on two freeways, I-405 and I-710. Double-blind health assessments included 24-hour ambulatory ECG, blood biochemistry, blood pressure, and lung function. Mean unfiltered particle number concentration was 107,500 particles/cm3 for I-710 and 77,800 particles/cm3 for I-405; mean PM-2.5 mass was 51.4 and 44.5 μg/m3 respectively. Filtration reduced particle count >95% but did not remove gases. Atrial ectopic beat incidence during and after exposure decreased 20% on average with filtered air compared to unfiltered air (P<0.05). Individual responses related most strongly to particle count (P=0.01). Blood markers NT pro-BNP and VEGF decreased 30% on average in filtered air compared to unfiltered air (P<0.05). These changes in blood biomarkers along with increased atrial ectopic beats are consistent with an increase in arryhthmia associated with exposure to traffic-related pollutants as seen in other studies. This study documents a cardiac and vascular response associated with freeway travel.

Speaker Biography

William C. Hinds, Sc.D., is a Emeritus Professor in the Department of Environmental Health Sciences at the UCLA School of Public Health. His primary research interests are fundamental and applied research related to aerosols (airborne particles) and industrial control of airborne contaminants including respiratory protection. Current and recent projects include the development of a multi-channel cascade impactor for task based exposure assessment, spatial profiles of ultrafine particles near freeways, nanoparticle exposure from industrial welding, and assessment of short-term health effects from exposure to freeway aerosol while traveling on a freeway. Professor Hinds has more than 100 publications in this field including a standard textbook on aerosol technology abd is a member in the UCLA Center for Occupational and Environmental Health. He is a former director of the UCLA Industrial Hygiene Program, a former director of the Southern California NIOSH Education and Research Center, and co-director of the UCLA component of the NIEHS Southern California Environmental Health Center. Professor Hinds is a member of the EPA Southern California Particle Center, Fellow of the American Industrial Hygiene Association, and a Certified Industrial Hygienist (CIH) (comprehensive practice).

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