Investigation of alveolar macrophages from rats exposed to coal dust

Rats were exposed to the inhalation of coal dust from either Utah (low prevalence coalworkers' pneumoconiosis (CWP)) or Pennsylvania (high prevalence CWP). Rats were sacrificed, the lungs removed and lavaged to obtain free cells. The number of alveolar macrophages recovered from rats inhaling these two coal dusts (exposures up to 4 months) was not remarkably different from the number recovered from rats inhaling filtered room air. This is in contrast to results obtained after intratracheal intubation of the dust. The capacity of the lavaged cells to phagocytize and kill bacteria decreased after exposure to either dust. The activity of certain enzymes also decreased.