Abstract
Coal worker's pneumoconiosis and silicosis are still important respiratory diseases within the mining industry. Bronchoalveolar lavage is used to obtain samples from miners with respiratory disease to diagnose, investigate, and treat pneumoconiosis. More information is needed about the characteristics of these respirable mineral dusts and the retrieved lavage specimens to better understand and diagnose pneumoconiosis. We have used bronchoscopy to instill characterized mineral dusts into a focal area of nonhuman primate lung. Bronchoalveolar lavage was used to recover alveolar lining materials from dust-exposed and unexposed lung of the same individuals. We found that multiple doses of fibrogenic or nonfibrogenic dust could be bronchoscopically placed into a small focal area of the lung and that the dust and resulting lesions remained localized to the area of instillation. The characterized quartz dust produced marked focal fibrosis and necrosis that resembled progressive massive fibrosis, as seen in humans exposed to silica dusts. Characterized anthracite coal dust produced interstitial macrophage accumulation with slight fibrogenesis that resembled dust overload syndrome associated with nonfibrogenic nuisance dusts, as seen in other animal experiments. More cells were recovered from dust-exposed lung than from unexposed lung. Recovered cells were morphologically representative of the major cells within the lesions. This primate model provides abundant dust-exposed and unexposed cells and alveolar materials from the same individuals for in vitro examination, and permits improved experimental control over dust variables, lesion development, and individual animal variables in a primate model of progressive massive fibrosis due to silicosis.