Environmental health literacy should integrate perceptions from both environmental and health literacy to ensure informed choices, improve quality of life, reduce health risks, and protect the environment. In this context, the term “environment” means a space surrounding a microbe, or neighborhood of house, or the village/city where we live, or the planet earth along with space surrounding it. The overall human health can be affected due to adverse changes in the different components of the environment and human health. Interaction of biological communities with their physical environment changes the environment that in turn can affect the health of the human beings. In addressing the above, this chapter discusses the fundamentals of environmental science and the relation of the environment to human health.