Project at a Glance

Title: Effects of prolonged, sequential exposure to acid fog and ozone on pulmonary function in exercising, normal subjects

Principal Investigator / Author(s): Balmes, John

Contractor: University of California, San Francisco

Contract Number: A833-078

Research Program Area: Ecosystem & Multimedia Effects

Topic Areas: Ecosystem Impacts, Health Effects of Air Pollution


Objectives:To determine whether pre-exposure to an acidic fog increases the effects of acute ozone exposure in healthy human subjects.

Findings: Pre-exposure to acidic fog did not have an additive or synergistic effect on ozone exposure responses. However, the results indicated the possible existence of a susceptible or sensitive population subgroup, who appear healthy and/or are asymptomatic, who are adversely affected by ozone exposure.

Importance to ARB's Program: The results were used in the final assessment of the Kapiloff program projects. (The Kapiloff program was the first formal investigation of atmospheric acidity in the world. The ARB's Atmospheric Acidity Protection Program was a more detailed investigation that was implemented as a result of Kapiloff findings.) If the increased sensitivity in the silent or asymptomatic group is confirmed in a randomly selected group from the general population, it will be necessary to modify the health advisories issued to protect the sub-group.

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

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