U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment
The mission of National Center for Environmental Assessment (NCEA) of EPA's Office of Research and Development is to provide guidance and risk assessments aimed at protecting human health and the environment. To accomplish this mission, NCEA works to develop and improve the models, databases, tools, assumptions, and extrapolations used in risk assessments. This handbook is a tool developed by NCEA aimed at refining the assumptions used in exposure assessments and reducing uncertainty.
This handbook was first published in 1989 and later updated in 1997 to provide statistical data on the various human factors used in assessing exposure. This revised edition of the handbook provides the most up-to-date data on these exposure factors. The recommended values are based solely on our interpretations of the available data. In many situations different values may be appropriate to use in consideration of policy, precedent or other factors.
The Exposure Factors Handbook provides a summary of the available statistical data on various factors used in assessing human exposure. This Handbook is addressed to exposure assessors inside the Agency as well as outside, who need to obtain data on standard factors to calculate human exposure to environmental agents.
These factors include: drinking water consumption, soil ingestion, inhalation rates, dermal factors including skin area and soil adherence factors, consumption of fruits and vegetables, fish, meats, dairy products, homegrown foods, human milk intake, human activity factors, consumer product use, and building characteristics. Recommended values are for the general population and also for various segments of the population who may have characteristics different from the general population. NCEA has strived to include full discussions of the issues that assessors should consider in deciding how to use these data and recommendations.
