Step 1.1 Identifying Exposure Categories


Oak Estates Example

After gathering preliminary information, the health assessor must determine the exposure pathway category for each identified exposure pathway at Oak Estates. [Note: Oak Estates is a hypothetical community introduced in the first course in this series: “Public Health Assessment Overview- 1: Mission and Community.”] Each pathway will be categorized as completed, potential, or eliminated based on the information about the site.

Findings. Site investigations state that Aroclor 1254 and arsenic are in surface soil samples collected at the closed landfill. People living in the retirement community built on the landfill have flower gardens. No surface soil samples have been collected from the flower beds.

To identify the exposure pathway category, the health assessor considers the five possible pathway elements: the contaminant source or release, the environmental fate and transport, the exposure point or area, the exposure route, and the potentially exposed population. The health assessor will likely identify the landfill as the source of contamination and soil as the medium.

Consequently, the health assessor would probably make the following decisions about the exposure pathway categories for Oak Estates.

The health assessor would reject the completed pathway category because all five elements are not present. The health assessor would assign a potential pathway category because it is possible that the missing elements might be present or might have been present even though the pathway elements cannot be identified. The health assessor would reject the eliminated pathway category because the findings do not rule out that all five pathway elements could be present.

Page last reviewed: May 31, 2016