Assessing and predicting the effects of environmental contaminant on human health remains a difficult and controversial problem. Developing sound, quantitative methods for predicting human risks requires developing accurate methods and models for assessing exposure, understanding molecular mechanisms of toxicity, and developing risk assessment models that incorporate information on mechanisms of toxicity. The current risk assessment process has been criticized because it lacks a connection between human physiology and potential risk after exposure to xenobiotics. Further, laboratory toxicologists are disconnected from the risk assessment process. To meet the need for toxicologists trained in the areas required for rational, science- based human risk assessment, the investigators propose a pre-doctoral training program that emphasizes a trans-disciplinary approach to understanding risk assessment at the molecular level. The proposed training program focuses on the study of (1) modem exposure assessment, (2) molecular toxicology, (3) modern epidemiology, and (4) integrating physical-biological sciences to develop sound policy for risk assessment and management. Students will take an integrated approach to the study of exposure assessment, toxicological problems caused by exposure to chemicals in the environment, and methods used to assess exposure pathways. In-depth study of environmental toxicology will focused on biological and molecular mechanisms involved in the response of organisms to environmental agents. Development of biological markers and their use as tools for epidemiologic studies from toxicologic studies will be achieved through advanced courses and laboratory study in toxicology, molecular epidemiology, and exposure assessment. This training program is targeted at pre-doctoral students. The trans-disciplinary training in this program will encourage collaborations between researchers specializing in the diverse fields required for rational, science-based assessment of human risk.