ARB Research Seminar

This page updated July 26, 2013

Asthma in Hispanic Children and Toxic Air Pollutants in a Southern California Community

Ralph J. Delfino, M.D., Ph.D., Department of Medicine, University of California, Irvine

May 06, 2003
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


Although acute adverse respiratory effects have been established for EPA criteria air pollutants such as ozone and particle mass, there is little information on respiratory effects from air pollutants such as volatile organic compounds (VOCs) from outdoor toxic emission sources. We evaluated acute effects of toxic air pollutant in Hispanic school children with asthma living in an East Los Angeles community with high traffic density. We also characterized VOC exposures using subject time-activity reports, breath sample GC-MS, and personal indoor home and outdoor stationary site VOC samplers. Our findings are compatible with the view that many VOCs, as well as criteria air pollutants, may be markers for a causal mixture of combustion-related pollutants. This view may be particularly relevant to consider for communities characterized by high automobile and truck traffic density. Results suggest more work is needed on potentially causal air toxics in the pollutant mix from both traffic and industrial sources.

Speaker Biography

Ralph J. Delfino's major research interests have been in understanding the effects of community air pollutants on respiratory health. He obtained his M.D. at the University of Chicago in 1987, and his Ph.D. in epidemiology and biostatistics from McGill University in 1993. Work at McGill focused on relationships of respiratory hospital admissions and of emergency room visits to outdoor air pollution levels in Montreal. He continues to contribute to this area of research by conducting panel studies of asthmatic populations in Southern California. Several studies have involved detailed exposure assessments involving personal air monitoring systems. His studies were among the first to show associations of daily asthma severity in children with personal ozone exposure and outdoor fungal spores. Other research results showed associations between asthma symptoms in children and increases in daily outdoor 1-hr and 8-hr maximum PM10. These particle associations were largely independent of maximum hourly O3. His ongoing NIH-funded research is expected to generate a better understanding of susceptibility to the adverse effects of air pollutants. Recent interest includes evaluating the role that urban air toxics play in relationships of acute asthma and of cardiovascular disease to routinely monitored air pollutants such as particle mass, O3, and nitrogen dioxide.

For a complete listing of the ARB Research Seminars and the related documentation
for the seminars please view the Main Seminars web page