Throughout the world, scientists and the general with environmental illness. Part II presents an over- public are concerned about the adverse effects of view of chemical and physical agents commonly toxic agents found in contaminated air, water, food, found in contaminated air, water, food, and soil. and soil. In the past, attention has focused on haz- The problem of hazardous wastes is also discussed. ards originating in the workplace. As a consequence, Part III characterizes the body's defense against occupational medicine has become a well-recognized such exposure. Defenses at the portals...