ARB Research Seminar
This page updated June 19, 2013
Heart Rate Variability Following Controlled Exposure to Particles and Ozone in Asthmatic Individuals
Dr. Karron Power, Department of Medicine, University of California, San Francisco
June 17, 2004
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA
- John Balmes, M.D., Mechanisms of Particulate Toxicity: An Overview
- Colin Solomon, Ph.D., Health Effects in Susceptible Humans
- Michael T. Kleinman, Ph.D., Inflammatory and Cardiovascular Responses to Inhaled Fine Particles
- Kent Pinkerton, Ph.D., Effects on the Respiratory System of Sensitive Animals and Asthmatic Humans
Alteration of heart function may underlie the increase in morbidity and mortality observed from exposure to ambient air particles and to ozone. Heart rate variability (HRV) measures the beat-to-beat changes in heart rate. Decreased HRV has been associated with increased cardiac mortality, and decreased HRV is seen with exposure to PM. The physiological mechanism underlying this effect is unknown, but may involve airway inflammation. An experiment was designed to test the hypothesis that controlled exposure to PM, and also to combined PM and ozone, would result in decreased HRV. Human subjects with allergic asthma were chosen for a controlled-exposure experiment because of the increased baseline airway inflammation inherent to asthma. Exposure to PM and ozone combined had a greater effect on HRV than exposure to PM alone.
Karron Power received her M.D. from the University of California at San Francisco and her M.P.H. in public health from the University of California at Berkeley. She is an assistant professor in the Department of Medicine at UCSF, in the Division of Occupational and Environmental Medicine. Dr. Power investigates the effects of air pollutants on cardiac autonomic function and airway inflammation using both controlled human exposures and epidemiologic studies.