Changes in the carbon dioxide expirogram in response to ozone exposure

Journal Article · Mon May 15 04:00:00 EDT 2006 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/j.taap.2005.09.009· OSTI ID:20783473

Taylor, Adekemi B ^[1]; Lee, Genea M ^[1]; Nellore, Kavitha ^[1]; Ben-Jebria, Abdellaziz ^[1]; Ultman, James S ^[1]

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1. Department of Chemical Engineering, Pennsylvania State University, 132B Fenske Laboratory, University Park, PA 16802 (United States)

The objectives of this study were to quantify pulmonary responses to ozone (O{sub 3}) exposure by parameters computed from the carbon dioxide expirogram and to compare these responses to decrements in forced expired spirometry. Anatomical dead space (V {sub D}) was determined from the pure dead space and transition regions of the expirogram. Four alternative parameters were computed from the alveolar plateau: slope (S), normalized slope (NS), peripheral cross-sectional area (A {sub P}) and well-mixed peripheral volume (V {sub MP}). Forty-seven healthy nonsmokers (25 men and 22 women) participated in two research sessions in which they exercised on a cycle ergometer for 1 h while orally inhaling either room air at a minute ventilation of 30.6 {+-} 3.6 L or room air mixed with 0.252 {+-} 0.029 ppm O{sub 3} at a minute ventilation of 29.9 {+-} 3.7 L. Carbon dioxide expirograms were measured before exposure, 10 min after exposure and 70 min after exposure. Percent changes (mean {+-} SD) in expirogram parameters were significant (P {<=} 0.002) at both 10 and 70 min after O{sub 3} exposure: V {sub D}(-4.2 {+-} 5.1, -3.3 {+-} 6.9), S(16.4 {+-} 17.9, +15.1 {+-} 20.2), NS(17.5 {+-} 15.4, +15.9 {+-} 19.2), A {sub P}(-8.1 {+-} 7.6, -7.7 {+-} 9.8) and V {sub MP}(-15.4 {+-} 13.0, -13.0 {+-} 15.2). Percent decrements of forced expired volume in one second (FEV{sub 1}) were also significant at both 10 min (-13.3 {+-} 13.4) and 70 min (-11.1 {+-} 9.2) following O{sub 3} exposure. Changes in the expirogram as well as decrements in FEV{sub 1} were not significant at either time point after air exposure. Thus, the CO{sub 2} expirogram is useful for characterizing the effect of O{sub 3} exposure on gas transport, and for supplementing forced expired spirometry that is frequently used to quantify lung mechanics.

• OSTI ID: 20783473
• Journal Information: Toxicology and Applied Pharmacology, Journal Name: Toxicology and Applied Pharmacology Journal Issue: 1 Vol. 213; ISSN TXAPA9; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
AIR
BIOLOGICAL EFFECTS
CARBON DIOXIDE
INHALATION
LUNGS
OZONE
VENTILATION