Longitudinal distribution of ozone absorption in the lung: Effect of continuous inhalation exposure
- Pennsylvania State Univ., University Park, PA (United States)
The effect of continuous exposure to ozone on the absorption of ozone in the conducting airways of human lungs was investigated with a bolus-response method. Eleven healthy nonsmoking college students (8 males, 3 females) were exposed at rest for 2 h on 3 separate days to air containing 0 ppm, 0.12 ppm, and 0.36 ppm ozone. A personal inhalation chamber equipped with a head-only clear plastic dome was used for exposure. Every 30 min a subject removed the dome and orally inhaled a series of five ozone-air boluses, each in a separate breath. Penetration of the boluses distal to the lips was targeted in the range of 70-120 ml (corresponding to the central conducting airways). By integrating the inhaled and exhaled-ozone concentration curves, we obtained the absorbed fraction {Lambda} and the dispersion ({sigma}{sup 2}) of the ozone bolus for each test breath. In addition, the subtraction of baseline measurements made just before exposure enabled us to determine the changes in absorbed fraction ({Delta}{Lambda}) and in dispersion ({Delta}{sigma}{sup 2}) that resulted from exposure alone. Absorbed fraction decreased, but {sigma}{sup 2} increased during O{sub 3} exposure, and the differences in {Delta}{Lambda} and in {Delta}{sigma}{sup 2} between breathing air and exposure to either 0.12 ppm or 0.36 ppm O{sub 3} were significant. We concluded that exposure of the conducting airways to O{sub 3} reduced their capacity to absorb O{sub 3}, possibly by the depletion of biochemical substrates that are normally oxidized by O{sub 3}. 20 refs., 9 figs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 530606
- Journal Information:
- Archives of Environmental Health, Vol. 51, Issue 6; Other Information: PBD: Nov-Dec 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Longitudinal distribution of ozone absorption in the lung: Effects of respiratory flow
Pulmonary function responses to ozone in smokers with a limited smoking history