TY - JOUR
T1 - Ozone uptake in the intact human respiratory tract
T2 - Relationship between inhaled dose and actual dose
AU - Rigas, Marc L.
AU - Catlin, Sandra N.
AU - Ben-Jebria, Abdellaziz
AU - Ultman, James S.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2000
Y1 - 2000
N2 - Inhaled concentration (C), minute volume (MV), and exposure duration (T) are factors that may affect the uptake of ozone (O3) within the respiratory tract. Ten healthy adult nonsmokers participated in four sessions, inhaling 0.2 or 0.4 ppm O3 through an oral mask while exercising continuously to elicit a MV of 20 l/min for 60 min or 40 l/min for 30 min. In each session, fractional absorption (FA) was determined on a breath-by-breath basis as the ratio of O3 uptake to the inhaled O3 dose. The mean ± SD value of FA for all breaths was 0.86 ± 0.06. Although C, MV, and T all had statistically significant effects on FA (P < 0.0001, P = 0.004, and P = 0.026, respectively), the magnitudes of these effects were small compared with intersubject variability. For an average subject, a 0.05 change in FA would require that C change by 1.3 ppm, MV change by 46 l/min, or T change by 1.7 h. It is concluded that inhaled dose is a reasonable surrogate for the actual dose delivered to a particular subject during O3 exposures of <2 h, but it is not a reasonable surrogate when comparisons are made between individuals.
AB - Inhaled concentration (C), minute volume (MV), and exposure duration (T) are factors that may affect the uptake of ozone (O3) within the respiratory tract. Ten healthy adult nonsmokers participated in four sessions, inhaling 0.2 or 0.4 ppm O3 through an oral mask while exercising continuously to elicit a MV of 20 l/min for 60 min or 40 l/min for 30 min. In each session, fractional absorption (FA) was determined on a breath-by-breath basis as the ratio of O3 uptake to the inhaled O3 dose. The mean ± SD value of FA for all breaths was 0.86 ± 0.06. Although C, MV, and T all had statistically significant effects on FA (P < 0.0001, P = 0.004, and P = 0.026, respectively), the magnitudes of these effects were small compared with intersubject variability. For an average subject, a 0.05 change in FA would require that C change by 1.3 ppm, MV change by 46 l/min, or T change by 1.7 h. It is concluded that inhaled dose is a reasonable surrogate for the actual dose delivered to a particular subject during O3 exposures of <2 h, but it is not a reasonable surrogate when comparisons are made between individuals.
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U2 - 10.1152/jappl.2000.88.6.2015
DO - 10.1152/jappl.2000.88.6.2015
M3 - Article
C2 - 10846013
AN - SCOPUS:0033933099
VL - 88
SP - 2015
EP - 2022
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 6
ER -