News Release

UCI to lead first public health study exploring link between air pollution and heart disease

Project will track how ultrafine air particles impact the elderly

Grant and Award Announcement

University of California - Irvine

Irvine, Calif., Dec. 9, 2003 – A UC Irvine epidemiologist will lead the nation's first public health study to understand how ultrafine particles in urban air pollution contribute to coronary heart disease in the elderly.

Supported by a $3-million National Institutes of Health grant, Dr. Ralph Delfino, an associate professor in the College of Medicine, and colleagues from UCI and the University of Southern California will monitor elderly individuals to see how daily pollution levels impact their ailments. These seniors will have existing heart disease and live in Southern California retirement homes impacted by high regional or local air pollution.

"Heart disease is the leading cause of hospitalization and death among the elderly," Delfino said. "If we can learn more about the relationship between heart disease and the ultrafine particles in smog, it could lead to air pollution regulations that better protect our health, improved medical treatment and longer and healthier lives for our senior population."

The researchers anticipate finding an association between the amount of ultrafine particles in the air and the severity of heart disease in the study subjects. Although very small in size, these particles carry condensed toxic elements that in numerous laboratory studies were found to trigger lung and heart inflammation and a host of cardiac ailments, such as blood clots, hardening of the arteries and heart disease.

Ultrafine particles are produced primarily by engine combustion, with diesel engine exhaust containing a particularly high concentration. Because they are so small (less than 100 nanometers in size), they are easily absorbed into blood stream and individual cells.

Currently, local and federal agencies do not regulate ultrafine particle emissions.

Delfino and his colleagues will base one part of the study in the Los Angeles area, near the traffic sources of ultrafine particles, and another in the Riverside area, where these particles undergo chemical reactions that may add to their toxicity.

Over a seven-month period, the researchers periodically will monitor certain markers of cardiac disease, such as changes in electrocardiographic readings, blood pressure and levels of inflammatory and clotting factors in the blood, to see how results of these tests change in comparison to ultrafine particle levels measured concurrently. Study subjects also will be intensely examined during the high-smog summer months and between October and January, when ultrafine particle levels can be even higher.

"We anticipate that when the subjects in our study are exposed to increased amounts of ultrafine particles, it will result in raised levels of the cardiac disease markers we will be measuring, which is a signal that a person's ailments are possibly worsening," said Delfino, who in another study is tracing particle effects on children with asthma.

"Because of its traffic and smog levels, Southern California is a perfect place to conduct this study," Delfino added. "But it shouldn't be seen as relevant only to this area. The health impacts of fossil fuel combustion are found nearly everywhere in this country, and you'll be exposed to these pollutants one way or another. This is a national health issue."

Participating in the study from UCI are cardiologists Dr. John Longhurst and Dr. Shaista Malik, toxicologist Michael Kleinman, biomedical engineer Dr. Steven George, psychosocial stress researcher Larry Jamner and biostatistician Christine McLaren. Participating from USC are environmental scientists Philip Fine and Constantinos Sioutas, associate professor of civil and environmental engineering and deputy director of the Southern California Particle Center and Supersite.

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The University of California, Irvine is a top-ranked public university dedicated to the principles of research, scholarship and community. Founded in 1965, UCI is among the fastest-growing University of California campuses, with more than 24,000 undergraduate and graduate students and about 1,300 faculty members. The third-largest employer in dynamic Orange County, UCI contributes an annual economic impact of $3 billion.

UCI maintains an online directory of faculty available as experts to the media. To access, visit: www.today.uci.edu/experts.


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