OZONE-INDUCED DECREMENTS IN FEV(1) AND FVC DO NOT CORRELATE WITH MEASURES OF INFLAMMATION

In order to test the hypothesis that changes in lung function induced by ozone (O-3) are correlated with cellular and biochemical indices of respiratory tract injury/inflammation, we exposed 20 healthy subjects , on separate days, to O-3 (0.2 ppm) and filtered air for 4 h during e xercise. Symptom questionnaires were administered before and after exp osure, and pulmonary function tests (FEV(1), FVC, and SRaw) were perfo rmed before, during, and immediately after each exposure. Fiberoptic b ronchoscopy, with isolated left main bronchus proximal airway lavage ( PAL) and bronchoalveolar lavage (BAL bronchial fraction, the first 10 mi of fluid recovered) of the right middle lobe, was performed 18 h af ter each exposure. The PAL, bronchial fraction, and BAL fluids were an alyzed for the following end points: total and differential cell count s, and total protein, fibronectin, interleukin-8 (IL-8), and granulocy te-macrophage colony-stimulating factor (GM-CSF) concentrations. The s tudy population was divided into two groups, least-sensitive (n = 12; mean O-3-induced change in FEV(1) = -7.0%) and most-sensitive (n = 8; mean O-3-induced change in FEV(1) = -36.0%). We found a significant O- 3 effect on SRaw (p < 0.001) and lower respiratory symptoms (p < 0.001 ) for all subjects combined, but no significant differences between th e least- and most-sensitive groups. Ozone exposure increased significa ntly percent neutrophils in PAL (p = 0.01); percent neutrophils, total protein, and IL-8 in bronchial fraction (p < 0.001, p < 0.001, and p < 0.01, respectively); and percent neutrophils, total protein, fibrone ctin, and CM-CSF in BAL (p < 0.001, p < 0.001, p < 0.01, p = 0.05, res pectively) for all subjects combined; there were no significant differ ences, however, between least- and most-sensitive groups. Our results indicate that levels of O-3-induced symptoms and respiratory tract inj ury/inflammation were not correlated with the magnitude of decrements in FEV(1) and FVC.