Appendix C - Passaic River Public Digital Library

4.2 Exposure Assessment
The objective of the exposure assessment is to estimate the magnitude, frequency, duration, and routes of
current and reasonably anticipated future exposure to COPCs associated with the site. The exposure
assessment is based on the receptor scenarios described in the CSMs that define the conditions of
exposure to site-related COPCs.
An exposure pathway defines the most probable pathway in which a receptor may come in contact with a
contaminated medium. For an exposure pathway to be complete, the following four elements must be
present
1. A source and mechanism of chemical release;
2. A retention or transport medium;
3. A point of contact between the receptor and the medium; and,
4. A route of exposure for the potential receptor at the contact point.
There must be a complete exposure pathway from the source of chemicals in the environment (i.e., from
sediment or biota tissue) to receptors for chemical intake to occur. If at least one exposure pathway is
complete, chemical intake may occur and adverse effects may be associated with site-related COPCs.
The complete exposure pathways identified in the PAR (Battelle, 2006a) are:
• Direct contact with surface water and/or sediment;
• Inhalation, incidental ingestion of sediment and/or surface water; and,
• Ingestion of fish/shellfish.
Individual CSMs were developed for the human health and ecological risk assessments to define the
exposure pathways for each assessment. Summaries of each of the relevant pathways with respect to
human and ecological health are provided in the following sections.
4.2.1 Human Exposures
Currently, the banks of the Lower Passaic River are extensively developed and surrounded by a mixture
of residential, commercial, and industrial activities. Intensive commercial and industrial uses occur in the
area due to a highly developed transportation infrastructure that includes highway, railway, and marine
services. Individuals are known to catch fish and crab along the river banks and from docks and
bulkheads (May and Burger, 1996; Burger et al., 1999; Kirk-Pflugh et al., 1999). In addition, several
rowing clubs engage in crew and other boating activities for adults and children, and a few parks, docks,
and mudflat areas are used by residents and visitors for recreational purposes. Currently, there are only a
few parks located along the river; however, future plans for the area include development of additional
parks, which may potentially increase the availability of the areas along the river for recreational uses by
local residents and visitors. Based on this information and ongoing initiatives to restore the Passaic River,
it was assumed that exposure to contaminants in the river would be associated with current recreational
activities such as swimming, wading, fishing, crabbing, and boating. Human receptors identified as
engaging in these activities include a Recreational User and an Angler/Sportsman. In addition, a transient
community has occasionally constructed temporary housing along the banks of the river. There is limited
information regarding the length of their occupancy and their activities while on the river; however, a
residential scenario (homeless resident) was also included in the CSM to address potential exposures to
this community. The receptors and exposure scenarios associated with future use are not expected to
differ significantly from those being evaluated under the current use scenarios. A summary of each of
these receptors and the complete exposure pathways associated with each is provided below and depicted
on Figure 4-1.
Draft Focused Feasibility Study Risk Assessment 4-3 June 2007
Lower Passaic River Restoration Project Appendix C