Table 3. Uncertainties Associated with Calculating the Average Daily Potential Dose

Table 3

Uncertainties Associated with Calculating the Average Daily Potential Dose

Equation from text:

ADDpot(mg/kg/day) = EPC H Abs H IR H FI H EF H ED

BWavg H AT

Term

Description

Default

Considerations/Uncertainty

ADDpot

Average Daily Potential Dose

Calculated value

EPC

Exposure point concentration

Site-specific data; calculated

Measure seafood tissue contaminant

or measured

concentrations if possible, or calculate as

detailed in text on Hazard Identification.

Abs

Fraction of contaminant absorbed

"1"

Depends on lipid composition and

from the seafood through the GI

preparation of seafood consumed.

tract

Ingestion rate

Site-specific data

Depends on the behavior of the seafood

consuming population.

Fraction ingested

"1" (subsistence and

See text for estimations of FI for

recreational fisherman)

commercial catch.

Exposure frequency

Approximate range of 10 to

Varies, depending on the behavior of the

100 meals/year

seafood-consuming populations.

Use site-specific data, especially if time of

Exposure duration

9 years (median)

capping of dredged material disposal is

30 years (upper-bound)

known.

Intermediate values should be used for

Body weight

70 kg (adults)

teenagers. Values for infants will be lower

15 kg (children)

than 15 kg.

Averaging time

70 years

In the absence of measured data for EPC, the risk assessment uses the tissue

concentrations of contaminants in the seafood estimated in the ecological risk

assessment. The EPC obtained from the application of these methods should be

expressed in milligrams (mg) of contaminants per kilogram (kg) of seafood.

The product of this step is an estimate of the concentration of COCs in seafood

exposed to the management area and its area of influence.

Chapter 4 Human Health Risk Assessment