Lung tissue slices are model systems for the study of pulmonary metabolism. Because of the speed and simplicity of slice preparation, lung slices have been used in studies of oxygen, amino acid, carbohydrate and lipid utilization and adenine nucleotide metabolism. Dose-response characteristics for toxicants are readily described because multiple lung samples can be studied from the same animal or a population of animals. Lung slices prepared from animals exposed to oxidant air pollutants exhibit alterations in respiration, glucose consumption and lipid metabolism. These studies have indicated both direct toxic effects of air pollutants on enzyme systems and also air pollutant-induced changes in the cellularity of lungs.