Conceptual basis for multi-route intake dose modeling using an energy expenditure approach.

This paper provides the conceptual basis for a modeling logic that is currently being developed in the National Exposure Research Laboratory (NERL) of the U.S. Environmental Protection Agency (EPA) for use in intake dose assessments involving substances that can enter the body via multiple routes of exposure. NERL is simultaneously developing a consolidated human activity database that will provide much of the data needed to parameterize equations used to implement the logic. EPA's Office of Air Quality Planning and Standards (OAQPS) is, in part, using the logic in its on-going review of the carbon monoxide national ambient air quality standard.