Response to Ozone in Volunteers with Chronic Obstructive Pulmonary Disease

Twenty-eight volunteers with chronic obstructive pulmonary disease were exposed to 0.0, 0.18, and 0.25 ppm ozone in purified air for 1-hr periods with light intermittent exercise, with exposure conditions presented in random order at 1-month intervals. No statistically significant changes attributable to ozone were found in forced expiratory performance or percent oxyhemoglobin (measured near the beginning and end of each exposure). No ozone-related changes in clinical status were found by interviews that included the time for 1 wk before to 1 wk after each exposure, except that a moderate increase in lower respiratory symptoms was reported by nonsmokers in 0.18 ppm exposures only. Thus, a slight decrement in hemoglobin saturation with ozone exposure (reported in two previous studies of chronic obstructive pulmonary disease subjects) may not be a common occurrence under typical ambient exposure conditions.