Exposure assessment is an essential tool for understanding, managing, controlling, and reducing occupational health risks in large and small workplaces. Data from exposure assessments are used in improving conditions in the workplace as well as in toxicology, epidemiology, and engineering studies. While important gains have been made in creating new methods and detecting even lower exposures for some substances and agents, numerous important challenges remain. For example, the benefits of exposure assessment are still not realized in many workplaces. Many substances, agents, and stressors lack exposure methods. Exposure data are not currently aggregated on a national basis to support improved priority setting for occupational health. This course focuses on existing techniques as well as the development of new approaches for the measurement and control of the same four broad stressor categories, chemical, physical, biological and ergonomic stressors in public and private workplaces and environments.