Continuum from Emission of an Agent to a Health Effect

In the context of exposure assessment, an investigator needs to look at data from the source of an agent of interest to time-activity pattern data of populations under study simultaneously to identify susceptible populations (Wallace LA, 1995). Characterizing major components of the continuum of source-exposure-dose-health effects is a must (Lioy PJ, 1990). (See Figure 1 below.) For example, the source data provide a profile of agents and emission rate of agents; and time-activity pattern data tell us how each of the individuals in the population contact the agents, as well as the frequency and intensity of those contacts (EPA, 1992).

Figure 1-1: Continuum from Emission of an Agent to a Health Effect

Adapted from Lioy, 1990