The emergence of epidemiologyEpidemiology as a distinct scientific field dates back to the seventeenth century, a period marked by favorable conditions for the collection, analysis, and interpretation of population data. In the eighteenth century, the field evolved further with the advent of comparative population studies, leading to the formal establishment of population study methods and practices. Modern epidemiologyEpidemiology has its roots in these developments. A critical subfield, environmental epidemiologyEpidemiology, specifically investigates the relationship between environmental factors and disease development. It focuses on the role of physical, chemical, and biological agents in the environment that may pose risks to large populations. Utilizing observational science methodologies, environmental epidemiologyEpidemiology draws conclusions from natural experiments occurring within human populations. This chapter provides a review of the fundamentals of environmental epidemiologyEpidemiology, including study designs and key measures used in research, based on an analysis of secondary sources. It highlights how recent advances in data science, technology, and biological sciences have positioned environmental epidemiologyEpidemiology at the forefront of efforts to combat human disease and promote public health.