Am. J. Respir. Crit. Care Med.,
Volume 158, Number 2, August 1998, 538-546
Cardiovascular Effects of Ozone Exposure in
Human Volunteers
HENRY
GONG Jr.,
RICHARD
WONG,
RADHA J.
SARMA,
WILLIAM S.
LINN,
EMMETT D.
SULLIVAN,
DEBORAH A.
SHAMOO,
KAREN R.
ANDERSON,
and
SHANKAR B.
PRASAD
Department of Medicine, Rancho Los Amigos Medical Center, Downey; University of Southern California School of Medicine,
Los Angeles; and South Coast Air Quality Management District, Diamond Bar, California
We hypothesized that ozone (O3) exposure acutely affects cardiovascular hemodynamics in humans
and, in particular, in subjects with essential hypertension. We studied 10 nonmedicated hypertensive and six healthy male adults. Each subject, after catheterization of the right heart and a radial artery,
was exposed in an environmentally controlled chamber to filtered air (FA) on one day and to 0.3 ppm
O3 on the following day for 3 h with intermittent exercise. Relative to FA exposure, O3 exposure induced no statistically significant changes in cardiac index, ventricular performance, pulmonary artery
pressure, pulmonary and systemic vascular resistances, ECG, serum cardiac enzymes, plasma catecholamines and atrial natriuretic factor, and SaO2. The overall results did not indicate major acute cardiovascular effects of O3 in either the hypertensive or the control subjects. However, mean preexposure to postexposure changes were significantly (p < 0.02) larger with O3 than with FA for rate-pressure product (1,353 beats/min/mm Hg) and for heart rate (8 beats/min); these responses were
not significantly different between the hypertensive and the control subjects. Significant O3 effects
were also observed for mean FEV1 (
6%), and AaPO2 (> 10 mm Hg increase), which were not significantly different between the two groups. These results suggest that O3 exposure can increase myocardial work and impair pulmonary gas exchange to a degree that might be clinically important in
persons with significant preexisting cardiovascular impairment, with or without concomitant lung
disease.