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
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.