Project at a Glance

Title: Cardiovascular effects of multipollutant exposure : mechanisms and interactions

Principal Investigator / Author(s): Kleinman, Michael

Contractor: UC Irvine

Contract Number: 13-309

Research Program Area: Health & Exposure

Topic Areas: Health Effects of Air Pollution


Epidemiological studies have associated higher levels of heart-related hospitalizations and deaths with exposures to elevated levels of fine particle (PM2.5). Ozone (O3) has been implicated in respiratory health effects, but there is also evidence of O3-related deaths from heart-related illnesses. Biologically, inhalation of either of these pollutants can result in formation of ROS, oxidative stress, and inflammation, which are involved in the formation of atherosclerotic plaques, increases in blood pressure, changes in heart rate variability and increased frequencies of abnormal heart beats. Therefore, the present study investigated whether chronic exposure to these two pollutants acting in concert can produce worse outcomes than either acting alone. One of the main findings of the study was that, counter to expectations, effects of concurrent chronic exposures to CAPs + O3 were not worse than the effects of exposures to the individual pollutants. A second important finding was that CAPs generated in ambient air during periods of high photochemical activity (i.e. summer) may be more toxic than CAPs generated in the lower photochemical period. Finally, it was determined that the effects of long-term exposure to CAPs with the organic constituents removed (deCAPs), when added to O3, did not differ from the effects of O3 alone. These results highlight the importance of understanding the complexity of interactions between air pollutants and their health impacts, which should be considered in setting regulations and ambient air quality standards to protect the health of all Californians.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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