CONCEPTUAL-FRAMEWORK FOR DESIGNING A NATIONAL SURVEY OF HUMAN EXPOSURE

The development and implementation of a National Human Exposure Assess ment Survey requires a sound conceptual framework in order to select t he population for study, the chemicals of concern, and the media and r outes of exposure requiring direct and indirect measurements. A three- level conceptual model is presented within a multidimensional space th at provides the basic parameters needed to be considered in the design of such a study. The axis common to all three levels is the duration of exposure. A fundamental need in a national survey is information on environmentally relevant chemicals, the biological mechanisms and hea lth responses, the types of personal contact, the environmental concen trations, the sources, and the populations at risk. Application of the model is appropriate for exposures that can lead to acute or chronic health effects. Five chemicals are used to illustrate the need for mul timedia and multiroute exposure analyses of the general population.