This research and research training program emphasizes a variety of laboratory studies and epidemiologic approaches to the study of the effects of environmental and occupational factors on the health of man. Specific examples include the following: morphology and cytochemisty of lysosome formation in alveolar macrophages; effect of breathing pattern and lung volume on the distribution of inhaled radioactive particles; effect of inhibition or alteration of biotransformation; development and exploitation of differentiated mammalian cell culture systems to detect, examine the mechanisms o action, and develop means for prevention or reversal of certain evnironmental chemical toxic agents; development of new chemical and immunologic assay methods for certain classes of environmental chemicals; development and use of affinity probes to identify the sites and molecular mechanisms of action of specific toxic agents; experimental lung cancer; malignant transformation in vitro; cancer morbidity among rubber workers; mortality among Boston firefighters 1915-1975.