Background: Numerous causes can lead to chronic inflammatory lesions of the lower respiratory AIRWAYS including those recognized as chronic obstructive pulmonary disease (COPD), of which tobacco smoke has been established. Air pollution and smokes from indoor and outdoor origins are among the possible causes. However, further investigations are required on this issue.Materials and Methods: Amongst those who underwent diagnostic bronchoscopy in the pulmonary endoscopy unit, Tehran University of Medical Sciences from April 1975 to March 2000, 102 patients revealed generalized chronic changes of the AIRWAYS with significant anthracotic deposits. Their clinical manifestations, demographic data, radiological, biopsy and bronchial washing findings were evaluated and compared with a similar number of contemporary cases without anthracotic lesions but with a variety of established pathologies.Results: Clinically, the patients with anthracotic airway lesions were already respiratory cripples. Females (n=60) had been exposed to long-term indoor smoke inhalation while baking home-made bread. Males (n=42) had a variety of occupations that entailed heavy smokes. Those without bronchial anthracosis had no similar histories.Conclusion: Long-term smoke inhalation can cause chronic anthracotic bronchopathies leading to respiratory invalidism. The problem seems to be extensive and has not confined to Iran. Further worldwide studies are required to address different aspects, including prevention of these ailments.

Airway mucus is difficult to clear and to improve lung function clearance of mucus is necessary. The deep coughing, chest physiotherapy, high frequency chest wall oscillation etc. are some of the best methods to clear excessive mucus from lung AIRWAYS. In this article we analysed the behavior of fluid flow between parallel walls, where both walls are porous and the flow is induced by the oscillation of these walls and pressure gradient; which is applicable for clearance of mucus from lung AIRWAYS. Generalized couette flow is applicable to model the oscillation of parallel walls, however the laminar flow of viscous fluid is taken under consideration. The generalized Navier-Stokes equations are applied to make various hypotheses and finite difference scheme is used to solve the problem numerically. Effect of wall oscillation, wall porosity, pressure due to porous media on mucus clearance and particle aspect ratio on the deposition of nonspherical nanoparticles are analysed graphycally after simulating the problem on MATLAB R2013a by user defind code. Simulation show an excellent agreement of unsteady flow of viscous fluid at large values of time and significant correlation between pressure gradient and porosity of walls, frequency of wall oscillation and their imapct on mucus clearance are obtained. In addion it is observed that fluid and particle velocity are increased with the enhancement of media porosity, breathing frequency and aspect ratio. The aim of this paper is to study the influence of wall movement, wall porosity, pressure on wall, wall oscillating frequency on the clearance of mucus from lung AIRWAYS.