The human body is exposed to different environmental aggressions; accidents, physical, chemical, and microbiological agents are a permanent risk. The respiratory system is particularly exposed to environmental aggressions and is frequently ground of alterations with greater or lesser intensity and danger. The authors review the consequences of air pollution on the respiratory system. They define air pollution, indoor and outdoor pollution, and primary and secondary pollution. They briefly review respiratory system defense mechanisms and describe harmful actions of different air pollutants to airways: SO2, NO2, CO, O3, aerosols and particles. They point to the consequences of tobacco smoking due to its importance to health. They conclude with comments on the intervention that Pneumology and Pneumologists should have in this matter, drawing the attention of the community and authorities to the risks of pollution to health in general and to the respiratory system in particular.

Objective: To assess the sensitivity and specificity of flow-volume curves in detecting central airway obstruction (CAO), and to determine whether their quantitative and qualitative criteria are associated with the location, type and degree of obstruction. Methods: Over a four-month period, we consecutively evaluated patients with bronchoscopy indicated. Over a one-week period, all patients underwent clinical evaluation, flow-volume curve, bronchoscopy, and completed a dyspnea scale. Four reviewers, blinded to quantitative and clinical data, and bronchoscopy results, classified the morphology of the curves. A fifth reviewer determined the morphological criteria, as well as the quantitative criteria. Results: We studied 82 patients, 36 (44%) of whom had CAO. The sensitivity and specificity of the flow-volume curves in detecting CAO were, respectively, 88.9% and 91.3% (quantitative criteria) and 30.6% and 93.5% (qualitative criteria). The most prevalent quantitative criteria in our sample were FEF50%/FIF50% ≥ 1, in 83% of patients, and FEV1/PEF ≥ 8 mL . L−1 . min−1, in 36%, both being associated with the type, location, and degree of obstruction (p < 0.05). There was concordance among the reviewers as to the presence of CAO. There is a relationship between the degree of obstruction and dyspnea. Conclusions: The quantitative criteria should always be calculated for flow-volume curves in order to detect CAO, because of the low sensitivity of the qualitative criteria. Both FEF50%/FIF50% ≥ 1 and FEV1/PEF ≥ 8 mL . L−1 . min−1 were associated with the location, type and degree of obstruction.

Keywords: Bronchoscopy; Maximal expiratory flow-volume curves; Sensitivity and specificity; Lung neoplasms.