Important aspects of workplace spirometry are discussed and recommendations are provided for the performance and interpretation of workplace spirometry.
To compare the responses of asthmatic and normal subjects to high effective doses of ozone, nine asthmatic and nine normal subjects underwent two randomly assigned 2-h exposures to filtered, purified air and 0.4 ppm ozone with alternating 15-min periods of rest and exercise on a cycle ergometer (minute ventilation = 30 l.min-1.m-2). Before and after each exposure, pulmonary function and bronchial responsiveness to methacholine were measured and symptoms were recorded. Ozone exposure was associated with a statistically significant decrease in forced vital capacity (FVC), forced expired volume in 1 s (FEV1), percent FEV1 (FEV1%), and forced expired flow at 25-75% FVC (FEF25-75) in both normal and asthmatic subjects. However, comparing the response of asthmatic and normal subjects to ozone revealed a significantly greater percent decrease in FEV1, FEV1%, and FEF25-75 in the asthmatic subjects. The effect of ozone on FVC and symptom scores did not differ between the two groups. In both normal and asthmatic subjects, exposure to ozone was accompanied by a significant increase in bronchial responsiveness. We conclude that exposure to a high effective ozone dose produces 1) increased bronchial responsiveness in both normal and asthmatic subjects, 2) greater airways obstruction in asthmatic than in normal subjects, and 3) similar symptoms and changes in lung volumes in the two groups.
A work-related interstitial lung disease has been diagnosed in workers at five nylon flock facilities in three different states and a Canadian province. The National Institute for Occupational Safety and Health hosted a workshop at which consulting pulmonary pathologists reviewed lung tissue samples from all the cases for which lung biopsy material was available (15 of 20 cases known in January 1998). After independent review and scoring of these lung tissue specimens, the pathologists reached consensus that the histopathological findings revealed a characteristic lesion-a lymphocytic bronchiolitis and peribronchiolitis with lymphoid hyperplasia represented by lymphoid aggregates. The pathologists noted that the pathological findings were distinctive when compared with known lung conditions. The clinical presentation for the cases generally included cough, dyspnea, restrictive ventilatory defect with reduction in diffusing capacity, and interstitial markings on chest radiographs or high-resolution computed tomography (HRCT) scans. Six of the cases improved after removal from workplace exposure without medical treatment. Six others, who had recovered with medical treatment and removal from the workplace, had relapses in both symptoms and objective findings after attempting to return to nylon flock work. With this and other evidence supporting the existence of chronic interstitial pneumonitis associated with nylon flock processing, workshop participants recommended surveillance for early identification of affected workers and their removal from further workplace exposure.
We are interested in the mechanisms of ozone-induced lung effects after short-term exposure and the relationship with subsequent pulmonary inflammation and disease. Our hypothesis is that ozone, as a powerful oxidant, will diminish the activity of neutral endopeptidase (NEP) in the airways of humans with resulting increased concentrations of neuropeptides such as substance P (SP). We have exposed seven (two women, five men) healthy, nonsmoking individuals (22 to 30 yr of age) to filtered air and ozone (0.25 ppm) for 1 h in an environmental chamber during heavy exercise. Bronchoscopy with airway lavage (AL) and bronchoalveolar lavage (BAL) was performed immediately after ozone exposure. The lavage samples were analyzed by enzyme immunoassay for SP and 8-epi-prostaglandin F2 alpha (8-epi-PGF2 alpha) (a marker for oxidative free radical reaction) and by radioimmunoassay for complement fragments. FEV1 had declined 12.4 +/- 1.9% (mean +/- SEM) as a result of ozone exposure. The AL concentration for SP and 8-epi-PGF2 alpha and BAL concentration of C3a after ozone exposure were significantly higher than after the filtered air exposure (P < 0.05). There was a significant correlation between SP and 8-epi-PGF2 alpha concentrations in the AL fluid (r2 = 0.89 and P < 0.05). There were no changes in C5a in either compartment or any of the mediators in the plasma samples. These results extend previous results from animal studies suggesting that ozone's mechanism of action is through an oxidative reaction resulting in a decreased activity of NEP in the airways with a subsequent increase in the concentration and activity of SP.
The possible contribution of metabolites of arachidonic acid to the increased permeability of the alveolar-capillary barrier in the adult respiratory distress syndrome was examined by quantifying the pulmonary edema fluid concentrations of lipoxygenase and cyclooxygenase products. The concentration of leukotriene D4 in pulmonary edema fluid of 10 patients with the adult respiratory distress syndrome (18.5 +/- 6.8 pmol/ml; mean +/- SD), assessed by specific radioimmunoassay after isolation of the mediator, was significantly higher (P less than 0.001) than that of five patients with cardiogenic pulmonary edema (4.4 +/- 1.1 pmol/ml). The concentrations of leukotrienes B4 and C4, prostaglandin E2, and thromboxane B2 in edema fluid were not significantly different in the adult respiratory distress syndrome patients than in the other subjects with pulmonary edema. The edema fluid concentration of leukotriene D4 correlated with the ratio of edema fluid to plasma concentrations of albumin (r = 0.64). Leukotriene D4 thus may contribute to the permeability defect which allows an accumulation of protein-rich alveolar fluid in the adult respiratory distress syndrome.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.