ABSTRACT
To understand the relationship of the environment to humans and to understand how to protect humans from illness and injury, it will be necessary to discuss the ecosystem, ecosystem dynamics, and energy. Human impact on the environment and the various approaches, including risk assessment, epidemiological, economic, legal, and governmental aspects used to evaluate and resolve environmental problems, are discussed. To understand abnormal physiology, and the basis of human illness and injury, brief discussions on normal physiology, toxicology, and epidemic infectious disease are included. Finally, it is necessary to understand the role of professional environmental health practitioners, the skills that they need, and how they address the expanding scope of environmental problems.
