Exposure studies are a valuable tool for measuring the levels of pollutants that enter the body. Our exposure to pollutants in the environment is thus being studied in ever greater detail. How are these exposure studies conducted? What is their purpose? Under what circumstances are they carried out? This brochure, which provides an overview of this tool, is intended for everyone: citizens, organizations, and local elected officials. Its goal is to explain, in a concise and accessible manner, the principles of a bioaccumulation study in order to facilitate understanding of environmental health issues in our region.