Distribution of particulate matter and tissue remodeling in the human lung.

Abstract

We examined the relationship between intrapulmonary particle distribution of carbonaceous and mineral dusts and remodeling of the airways along anatomically distinct airway paths in the lungs of Hispanic males from the central valley of California. Lung autopsy specimens from the Fresno County Coroner's Office were prepared by intratracheal instillation of 2% glutaraldehyde at 30 cm H(2)O pressure. Two distinct airway paths into the apico-posterior and apico-anterior portions of the left upper lung lobe were followed. Tissue samples for histologic analysis were generally taken from the intrapulmonary second, fourth, sixth, and ninth airway generations. Parenchymal tissues beyond the 12th airway generation of each airway path were also analyzed. There was little evidence of visible particle accumulation in the larger conducting airways (generations 2-6), except in bronchial-associated lymphoid tissues and within peribronchial connective tissue. In contrast, terminal and respiratory bronchioles arising from each pathway revealed varying degrees of wall thickening and remodeling. Walls with marked thickening contained moderate to heavy amounts of carbonaceous and mineral dusts. Wall thickening was associated with increases in collagen and interstitial inflammatory cells, including dust-laden macrophages. These changes were significantly greater in first-generation respiratory bronchioles compared to second- and third-generation respiratory bronchioles. These findings suggest that accumulation of carbonaceous and mineral dust in the lungs is significantly affected by lung anatomy with the greatest retention in centers of lung acini. Furthermore, there is significant remodeling of this transitional zone in humans exposed to ambient particulate matter.

Lung Function Abnormalities in Petrol Pump Workers in Suburban Areas of Chennai

“…[12] In human lung, the major site of impact and injury for the particulate matter is at the level of terminal Section: Pulmonary Medicine bronchioles and the adjacent 1st generation respiratory bronchioles. [15] These particulate matter are usually not seen deposited in the larger bronchi as they are probably cleared from this area rapidly. [16] Also, the present study shows that the lung function abnormalities are increased if the duration of work in the petrol pumps are more.…”

Diesel Exhaust Particles Stimulate Adaptive Immunity by Acting on Pulmonary Dendritic Cells

“…Moreover, we detected DEPs within the mediastinal DCs. In humans, particulate matter has also been observed within biopsies of bronchial lymph nodes (31). Because this DEP translocation to the mediastinal DC population is a relevant finding to explain the effects upon inhalation, we investigated the DEP translocation mechanism.…”

Relative Effects of Air Pollution on Lungs and Heart

“…These particles tend to be retained in respiratory bronchioles within the central part of the acinus. 3,4 Their removal from respiratory bronchioles is inefficient for lack of cilia and lack of an appropriate surface for efficient removal by macrophages. Thus, chronic particle retention and tissue remodel-ing is common in the central acinus, where centriacinar (or centrilobular) emphysema develops in smokers.…”