Step 1.2 Gathering Health Concerns and Other Information

Exposure Pathway Determination

Let’s review the information we learned about 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.”]

The Oak Estates site was built on a closed landfill. The landfill may be producing gases that are moving from the landfill into the air. People living in Oak Estates report that they smell a foul odor in their neighborhood. Air samples were collected, and analysis detected some chemicals, but none that cause odors. The landfill may not be the cause of the odor, but the air that people in Oak Estates are breathing does contain some substance that causes the odor.

To help determine whether an exposure pathway exists at Oak Estates, the health assessor will evaluate the information known about the site. The health assessor may organize the information by using an exposure pathways table that lists the five elements of a completed exposure pathway. To be complete, an exposure pathway must contain all five of the following elements.

  • A source of the chemical.
  • An environmental medium through which the chemical travels.
  • A point of exposure.
  • A route of exposure.
  • An exposed population.

The pathway elements for Oak Estates may be identified as follows.

  • The possible source of the chemical is the landfill.
  • Air is the environmental medium in which the chemical is being transported with gases from the landfill.
  • The yards and homes in Oak Estates are the points of exposure.
  • The route of exposure is inhalation of the chemical in the air.
  • Residents and visitors to Oak Estates are the people exposed.
Page last reviewed: May 31, 2016