Pulmonary diseases caused by airborne contaminants in swine confinement buildings.

Exposure to toxic gases and particles or dusts while working or living in confinement animal systems pose a pulmonary health hazard. The severity of lung impairment from exposure to such environment is investigated using intratracheal instillation, intratracheal nebulization, and inhalation procedures. Ability to deliver particles with intratracheal instillation that are evenly distributed throughout the lung depends on the material used for injection. Pulmonary histopathology reflects anatomic changes following inhalation or instillation of chemicals or particles. Endobronchial saline washings of bronchioles and alveoli allow measurement of markers of pulmonary inflammation such as total nucleated cell (leukocyte) counts and those of macrophages, neutrophils and lymphocytes; TNF-alpha, and collagen concentration are used to further evaluate pulmonary response to endotoxin or dust exposure. Alveolar epithelial cells have an important role in clearing pulmonary fluid and maintaining the structure of lung tissue. After repeated exposure, damage to epithelial cells may result in their death, causing edema and collagen deposition that may lead to fibrosis.