DESCRIPTION: This is a request for continuing support for predoctoral and postdoctoral trainees in 4 broad areas of toxicology; cellular and molecular toxicology, carcinogenesis, neurotoxicology, and pulmonary toxicology. The objective of this training program is to provide a strong grounding in the principles of toxicology followed by specific expertise in one specific area. The intent is to produce trainees capable of conducting meaningful research in their field but also able to communicate with investigators in other sciences and fields of toxicology. For doctoral trainees this is achieved through formal didactic sessions followed by extensive laboratory work in a specific field of research. The formal didactic training consists of 33 hours of core course work, 3 elective courses, and 13 hours of focused research in 1 or 2 laboratories. Students have a comprehensive written examination at completion of course work, and both preliminary and oral examinations on their individual research proposal and dissertation.