Selecting and Characterizing Representative Receptor

Selecting and Characterizing Representative Receptors

What is a representative receptor?

Representative human receptors are humans who have a complete exposure pathway as described in the

conceptual model and whose exposure is likely to represent a reasonable worst-case exposure to the

COCs.

Representative ecological receptors are organisms whose life histories and habitat requirements fairly

represent the range of habitats and life histories for those organisms with complete exposure pathways

which are found near the dredged material management site.

Why does risk assessment use representative receptors?

It is practically impossible for the risk assessment to address risk to every possible receptor. There will be

a wide variety of species and types of species under the potential influence of the dredged material

management site. Therefore the ecological risk assessment must have some method to choose one or more

receptors which best represent the types of species likely to contact COCs from the dredged material

management area.

Similarly, human contact with contaminants may vary over a wide range, so it is important to choose a

human receptor which represents a realistic but likely worst case from among the range of possible human

receptors.

How will the risk assessment use representative receptors?

The risk assessment will use the biological properties and activity patterns of representative receptors to

develop estimates of how much contaminant the receptor may encounter. It will use toxicological

information about the receptor to estimate whether that level of contaminant exposure might present a risk

to the representative receptor. By broad extension, the assessment will assume that risk to the

representative receptors implies risk to ecological populations or individual humans.

Select and Characterize Representative Receptors

It is unreasonable to assume that a risk assessment can address potential risk to

every species or every human activity which may be associated with the dredged

material management activity. Therefore, the risk assessment uses representative

receptors. Representative human receptors are humans who have a complete

exposure pathway as described in the conceptual model, and whose exposure is

likely to represent a reasonable worst-case exposure to the COCs. Representative

ecological receptors are organisms whose life histories and habitat requirements

fairly represent the range of habitats and life histories found near the dredged

Chapter 2 Problem Formulation