Effects of ozone and other pollutants on the pulmonary function of adult hikers.

Abstract

This study evaluated the acute effects of ambient ozone (O3), fine particulate matter (PM2.5), and strong aerosol acidity on the pulmonary function of exercising adults. During the summers of 1991 and 1992, volunteers (18-64 years of age) were solicited from hikers on Mt. Washington, New Hampshire. Volunteer nonsmokers with complete covariates (n = 530) had pulmonary function measured before and after their hikes. We calculated each hiker's posthike percentage change in forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), the ratio of these two (FEV1/FVC), forced expiratory flow between 25 and 75% of FVC(FEF25-75%), and peak expiratory flow rate (PEFR). Average O3 exposures ranged from 21 to 74 ppb. After adjustment for age,sex, smoking status (former versus never), history of asthma or wheeze, hours hiked, ambient temperature, and other covariates, there was a 2.6% decline in FEV1 [95% confidence interval (CI), 0.4-4.7; p = 0.02] and a 2.2% decline in FVC (CI, 0.8-3.5; p =0.003) for each 50 ppb increment in mean O3. There were consistent associations of decrements in both FVC (0.4% decline; CI,0.2-0.6, p = 0.001) and PEFR (0.8% decline; CI, 0.01-1.6; p = 0.05) with PM2.5 and of decrements in PEFR (0.4% decline; CI, 0.1-0.7; p = 0.02) with strong aerosol acidity across the interquartile range of these exposures. Hikers with asthma or a history of wheeze (n = 40) had fourfold greater responsiveness to ozone than others. With prolonged outdoor exercise, low-level exposures to O3, PM2.5, and strong aerosol acidity were associated with significant effects on pulmonary function among adults. Hikers with a history of asthma or wheeze had significantly greater air pollution-related changes in pulmonary function.ImagesFigure 1Figure 2

Ozone exposure, antioxidant genes, and lung function in an elderly cohort: VA normative aging study

“…Other factors may increase the susceptibility to the effects of O 3 , such as outdoor physical activity. For example, the study of Korrick et al mentioned above found that hiking was a modifier of the effect of O 3 on lung function 38. While the lack of activity pattern data in our study is a concern, we have no reason to believe this could upwardly bias our effect, and the likely direction of the bias is downward 50.…”

“…A study evaluating the effects of ambient O 3 on 530 non-smoking hikers, aged 18–64, found significant associations between O 3 exposure and declines in FVC and FEV 1 38. When divided into four age categories, no difference in responsiveness to O 3 was found, suggesting that the associations found for the entire cohort are representative of the oldest age group (ages 48–64) for this sample population.…”

Associations of long- and short-term air pollution exposure with markers of inflammation and coagulation in a population sample

“…A higher effect of long-term air pollution exposure on physically active people could be linked to higher pulmonary ventilation and more outdoor exposure, with a consequent higher exposure load of polluted urban air. Other studies have reported exacerbation of asthma symptoms and decrease in lung function in athletes and hikers in response to elevated levels of air pollutants 31 32…”

Age-related association of fine particles and ozone with severe acute asthma in New York City

“…Increased ambient levels of ozone and PM 2.5 have been associated with reduced lung function, [1][2][3][4][5][6][7] worsening asthma symptoms, [8][9][10][11] asthma-related emergency department visits, [12][13][14][15][16][17][18][19][20] and hospitalizations. [21][22][23][24][25] Little is known, however, about the association of ambient air pollutants with a very severe asthma episode requiring intensive care unit (ICU) admission.…”