Introduction

Abstract

All people are exposed to complex and dynamic mixtures of chemicals and nonchemical stressors throughout their lives. Understanding how these combined exposures impact human health is an active area of research spanning exposure science, toxicology, epidemiology, statistics, and risk analysis. Mixtures under study range from simple combinations of chemicals to the complete exposure profile known as the exposome. Research efforts to explore mixtures have used individual chemical data to estimate mixture effects in a bottom-up approach and have evaluated the effects of whole mixtures in a top-down approach. Considering the numerous perspectives and approaches, mixture terminology has been particularly challenging. In this introductory chapter, we lay the groundwork for the book by providing a rationale for the study of mixtures, defining important terms, and describing the flow of the book.