In:
Journal of Applied Physiology, American Physiological Society, Vol. 95, No. 5 ( 2003-11), p. 1917-1925
Abstract:
Subjects were healthy nonsmoking men ( n = 146) and women ( n = 94) 18-60 yr old. Initially, each subject was exposed for 1.5 h to 0.42 ppm O 3 . Forty-seven individuals were later reexposed twice, 1 wk to several months apart, to 0.4 ppm O 3 . Intermittent exercise utilized in all exposures was adjusted to produce an O 3 dose of 560 ppm × l/m 2 body surface area. The post-O 3 percent change in forced-expiratory volume in 1 s (Δ%FEV 1 ) decrements of young (18-35 yr) and middle-aged (36-60 yr) men and women differed significantly ( P 〈 0.05) from normal distribution with values skewed toward larger decrements in younger subjects. The mean Δ%FEV 1 rates were -16.3%, -16.6%, -11.6%, and -6.4%, respectively. The rate of decline with age was 2.5 times higher in young women compared with young men ( P 〈 0.05). This pattern was reversed in the middle-age cohort. Our data support earlier reports of no significant difference in spirometric response to O 3 between young men and women. The data also confirm that large FEV 1 decrements after O 3 exposure are mostly confined to younger individuals that also show much greater variance in response to repeated exposures than the middle-aged subjects. The majority of subjects remained in their initial category of O 3 sensitivity on retesting after various time lapses. The r value (Spearman) between the first and second and first and third exposure response ranged from 0.544 to 850, depending on classification. However, the mean Δ%FEV 1 differed by as much as six percentage points between exposure days. The yearly loss of responsiveness (0.2% to 0.7%/year) with progressing age determined by cross-sectional analyses was substantially smaller.
Type of Medium:
Online Resource
ISSN:
8750-7587
,
1522-1601
DOI:
10.1152/japplphysiol.00490.2003
Language:
English
Publisher:
American Physiological Society
Publication Date:
2003
detail.hit.zdb_id:
1404365-8
SSG:
12
SSG:
31
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