Effects Assessment Workgroup

and associated bioavailability, should DOC be routinely measured in

elutriate tests or in ambient waters at disposal sites? What about acid

volatile sulfide in sediments)?

d. What models are available for predicting food chain transfer and

biomagnification in higher trophic level organisms in aquatic and terrestrial

ecosystems?

e. How reliable and useful are the available food chain models? What

uncertainties are associated with models of trophic transfer?

What are the advantages and disadvantages of the various approaches?

For example, how different are the predictions of the physiologically based

Gobas model in comparison to the Great Lakes Water Quality Initiative

approach which uses steady-state bioaccumulation factors (BAF) to

predict fish tissue concentrations from water concentrations? Are the

results from different approaches comparable?

g. Should 28-day body burden data be corrected for hydrophobic compounds

that are not expected to reach steady state in 28 days? How should steady

state for metals be addressed?

h. What are the largest sources of uncertainty in exposure assessment? How

can these uncertainties be reduced? How should these uncertainties be

characterized?

What are the appropriate temporal and spatial scales to characterize

exposure of dredged material management options?

How important is it to attain site-specific estimates of fish ingestion rates

for human health risk assessments? Is it important to incorporate

information on methods of food preparation?

k. What are the important areas for future research in exposure assessment?

Effects Assessment Workgroup

a. How reliable are the World Health Organization's 2,3,7,8-dioxin Toxic

Equivalency Factors (TEF) for fish, birds, and mammals?

b. What are the appropriate sources of data on toxicity?

c. How should the U.S. Army Corps of Engineers' Environmental Residue-

Effects Database (ERED) be used in effects assessment? For example, in

the absence of information on the species of interest, should minimum or

average residue-effects be used for comparison to test data sets?

Appendix C Discussion Items