PREFACE
The Exposure Factors Program of the U.S. Environmental Protection Agency’s (U.S. EPA’s) Office of
Research and Development (ORD) has three main goals: (1) provide updates to the Exposure Factors Handbook and
the Child-Specific Exposure Factors Handbook; (2) identify exposure factors data gaps and needs in consultation with
clients; and (3) develop companion documents to assist clients in the use of exposure factors data. The activities under
each goal are supported by and respond to the needs of the various program offices.
The National Center for Environmental Assessment (NCEA) of the U.S. EPA’s ORD has prepared this
handbook to provide information on various physiological and behavioral factors commonly used in assessing
children’s exposure to environmental chemicals. Children have different exposure circumstances than do adults.
Understanding these differences is key for evaluating potential for environmental hazards from pollutants. They
consume more of certain foods and water and have higher inhalation rates per unit of body weight than adults. Young
children play close to the ground and come into contact with contaminated soil outdoors and with contaminated dust
on surfaces and carpets indoors. Ingestion of breast milk is another potential pathway of exposure for infants and
young children.
NCEA published the Exposure Factors Handbook in 1997. That document includes exposure factors and
related data on children, as well as adults. However, the U.S. EPA Program Offices identified the need to prepare a
document specifically for children’s exposure factors. The Child-Specific Exposure Factors Handbook is intended to
fulfill this need.
This handbook was first offered to the public in 2002. Since that time, the U.S. EPA has incorporated updated
data and revised the recommendations for several exposure factors and developed a standardized set of age categories
to be used for children’s exposure assessment. Where possible, the U.S. EPA has used this standard set of age
categories to permit easier comparison of data among multiple sources and to allow consistency between different types
of exposure factors.
The Exposure Factors Program of the U.S. Environmental Protection Agency’s (U.S. EPA’s) Office of
Research and Development (ORD) has three main goals: (1) provide updates to the Exposure Factors Handbook and
the Child-Specific Exposure Factors Handbook; (2) identify exposure factors data gaps and needs in consultation with
clients; and (3) develop companion documents to assist clients in the use of exposure factors data. The activities under
each goal are supported by and respond to the needs of the various program offices.
The National Center for Environmental Assessment (NCEA) of the U.S. EPA’s ORD has prepared this
handbook to provide information on various physiological and behavioral factors commonly used in assessing
children’s exposure to environmental chemicals. Children have different exposure circumstances than do adults.
Understanding these differences is key for evaluating potential for environmental hazards from pollutants. They
consume more of certain foods and water and have higher inhalation rates per unit of body weight than adults. Young
children play close to the ground and come into contact with contaminated soil outdoors and with contaminated dust
on surfaces and carpets indoors. Ingestion of breast milk is another potential pathway of exposure for infants and
young children.
NCEA published the Exposure Factors Handbook in 1997. That document includes exposure factors and
related data on children, as well as adults. However, the U.S. EPA Program Offices identified the need to prepare a
document specifically for children’s exposure factors. The Child-Specific Exposure Factors Handbook is intended to
fulfill this need.
This handbook was first offered to the public in 2002. Since that time, the U.S. EPA has incorporated updated
data and revised the recommendations for several exposure factors and developed a standardized set of age categories
to be used for children’s exposure assessment. Where possible, the U.S. EPA has used this standard set of age
categories to permit easier comparison of data among multiple sources and to allow consistency between different types
of exposure factors.
