Project at a Glance

Title: Physiological effects of air pollutants in humans subjected to secondary stress

Principal Investigator / Author(s): Hackney, Jack D.

Contractor: Professional Staff Association of the Rancho Los Amigos Hospital, Inc.

Contract Number: 2-372

Research Program Area: Health & Exposure

Topic Areas: Health Effects of Air Pollution


Adult male volunteers were exposed to purified air or to ozone, alone or in combination with nitrogen dioxide and carbon monoxide, in an investigation of physiological effects of photochemical air pollution. Exposure conditions simulated those of a smoggy Southern California summer, including the secondary stresses of heat, exercise and repeated exposure. Pulmonary function, blood biochemistry, psychomotor performance capability, and symptoms experienced by the subjects were evaluated. Ozone exposures similar to those expected during pollution episodes produced significant decrement in pulmonary function, symptoms sufficient to restrict normal activity, and oxidative changes in erythrocytes. Psychomotor tracking ability and measures of attention were adversely affected by heat, but not by ozone exposure. Subjects with a history of cough, chest discomfort, or wheezing associated with allergy or exposure to air pollution, were more reactive than subjects without such a history. Addition of nitrogen dioxide and carbon monoxide to ozone in exposures did not produce additional detectable effects except for slight increases in carboxyhemoglobin levels and small variable decrements in psychomotor performance with carbon monoxide exposure. It is concluded that in sensitive subjects, exposures to photochemical oxidants at concentrations sometimes achieved in California urban areas may produce physiological dysfunction and inability to carry on normal activities.

This report was submitted in fulfillment of Contract No. ARB 2-372 by the Environmental Health Service/SCOR in Environmental Lung Disease, Rancho Los Amigos Hospital, under the sponsorship of the California Air Resources Board. Work was completed 30 June 1974.

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

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