This report presents the results of a study conducted to determine the effects of various energy-related effluents on respiratory tract epithelial tissue. Measurement of mucoiliary activity and characterization of the morphological alterations induced by such effluents was carried out in hamster tracheal organ culture. Different combinations of in vivo and in vitro exposure and/or maintenance were used to determine the relationship between in vivo exposure danger and adverse effects observed in organ tissue. The pollutants assessed included particulate effluents from mobile and stationary sources of both conventional and advanced energy processes. Included were fly ash (from coal-fired and oil-fired sources), cigarette smoke condensate, and diesel fuel exhaust extract, with benzo(a)pyrene serving as a positive control. Both acute (72-hr) and long-term 14-day studies permitted assessment of tissue specific effects. In addition to acute and long-term toxicity studies, testing was conducted to determine the effects of selected particulate effluents on the pathogenesis of viral infections.