The practice of exposure assessment: A state-of-the-art review (Reprinted from Principles and Methods of Toxicology, 4th edition, 2001)

Each of us encounters hundreds of toxic agents everyday, without exposure a nd subsequent absorption (uptake) however, there is no risk of injury. Thus , exposure assessment is one of the three legs of the stool (along with tox icity assessment and dose-response assessment) upon which the practice of r isk assessment rests. The Field of exposure assessment has evolved out of a t least 3 other disciplines over the past 50 years, including health physic s, industrial hygiene, and epidemiology. Exposure assessments are a necessa ry component to understanding the hazard posed by exposure to naturally (e. g., aflatoxins in foods, radon in air) and nonnaturally occurring toxicants (e.g., benzene in groundwater, MTBE in air, and food additives). This arti cle presents a thorough review of the field including a discussion of the t erminology used in exposure assessment, a description of how to quantitativ ely estimate dose for the major sources of exposure (food, water, air, and soil), and many of the best sources of information. In addition, techniques for assessing both variability and uncertainty are presented. Lessons lear ned over the past twenty years are emphasized. Some example calculations ar e included, nearly 400 references are cited, and a glossary of terms is pro vided.