Hazucha MJ, Folinsbee LJ, Bromberg PA. J Appl Physiol. 2003;95:1917–1925
Purpose of the Study.
To determine whether the effects of moderate ozone exposure on forced expiratory volume in 1 second (FEV1) values are influenced by age and gender.
Volunteers were healthy, moderately active, nonsmoking, nonallergic men (n = 146) and women (n = 94), of young age (18–35 years) or middle age (36–60 years).
After completing baseline questionnaires and pulmonary function tests, subjects were exposed to 0.42 ppm of ozone at 22°C and 40% humidity for 1.5 hours, alternating 20 minutes of exercise with 10 minutes of rest. During exercise, ventilation was monitored for 2 minutes and electrocardiograms were recorded at 5-minute intervals. Routine spirometric evaluations were repeated after exposure. Forty-seven subjects were reexposed to ozone on 2 subsequent occasions.
After the first exposure, the mean postexposure changes in FEV1 were −16.3% (range: +1% to −44%) for young men, −16.6% (range: +2% to −53%) for young women, −11.6% (range: 0% to −63%) for middle-aged men, and −6.4% (range: +2% to −28%) for middle-aged women. The levels of responsiveness of young men and women were similar, but the differences in responsiveness between all other pairs of groups were significant (P < .05). Young individuals showed greater changes on each exposure day than did middle-aged individuals (P < .05). The postexposure decreases in FEV1 tended to be smaller with increasing age for both genders, but the loss of response with aging was greater for women. The first exposure induced smaller effects, compared with subsequent exposures.
The changes in FEV1 after moderate ozone exposure decreased with increasing age for both men and women, suggesting that young individuals might be at higher risk for adverse health effects after ozone exposure.
Increasing attention is being paid to the effects of airborne pollutants, such as ozone, on childhood asthma. Although we must be cautious about extrapolating findings on the responsiveness of nonallergic adults to children with asthma, the results of this study suggest that the effects of ozone on pulmonary function may be greater among younger individuals.