Time course of ozone-induced neutrophilia in normal humans

Edward S Schelegle, A. D. Siefkin, Ruth J McDonald

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115 Scopus citations


Five normal human subjects were exposed for 1 h to filtered air (FA) once and to 0.3 ppm O3 on 3 separate days. Bronchoalveolar lavage (BAL) fluid was obtained < 1 h after FA and either < 1, 6, or 24 h after O3 exposure. FEV1 was measured before the exposures and the BAL. The first aliquot [proximal airway (PA) sample] was analyzed separately from the pooled Aliquots 2 through 4 [distal airway and alveolar surface (DAAS) sample]. The data from the PA and DAAS samples were then combined to calculate the values that would have been obtained by pooling all BAL washes. FEV1 was significantly (p < 0.05) decreased 1 h after O3 exposure, but it returned to preexposure values at 6 and 24 h after O3. The percent of neutrophils in the PA sample was significantly elevated at < 1 h (3.7%) at 6 h (16.5%), and at 24 h (9.2%) after O3. The percent of neutrophils in the DAAS sample and calculated pooled values were significantly elevated at 6 h (4.1 and 7.6%) and at 24 h (5.1 and 5.8%) after O3. These data demonstrate that O3-induced symptoms, FEV1 decrements, and airway neutrophilia follow different time courses and indicate that the pooling of BAL washes may obscure the detection of an O3-induced bronchiolitis. The degree of neutrophilia in the BAL did not correlate with the sensitivity of the individual subjects when measured by acute changes in FEV1, suggesting a dichotomy of pathways that result in O3-induced airway neutrophilia and pulmonary function decrements.

Original languageEnglish (US)
Pages (from-to)1353-1358
Number of pages6
JournalAmerican Review of Respiratory Disease
Issue number6
StatePublished - 1991

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine


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