 |
||
|
|
||
| |||||||||||||||
|
|
 dredged material site is different when compared to later exposures due to
the early presence of opportunistic species and their exposure to fresh
material.
b. Far-field exposure models must be validated. Fate and transport models
which predict particle transport and dissolved contaminant transport need
field validation. This is particularly important in addressing the potential
for off-site exposures from dispersive sites.
c. Food chain models that address exposures to metals must be developed or
acquired. Other programs (e.g., IAEA) may have food chain models for
metals. If so, the application of these to dredged material management
sites should be explored.
d. A database on regional sources of information must be developed. The
group recognized that much of the information necessary to do an exposure
assessment is from sources other than the dredged material Technical
Framework (USACE/USEPA 1992), sediment evaluation procedures
(USACE/USEPA 1991, 1998), or Site Designation Reports. A database
of information sources which describes the available categories of
information and how to obtain them will conserve time and resources
during development of the exposure assessment.
e. Protocols for the appropriate application and interpretation of in situ
"caged animal" studies must be developed. The group felt that caged
animal studies are a nonroutine measurement and that the USACE should
develop a protocol regarding their use. The protocol should provide clear
guidance on when such measurements may be helpful in addressing
exposures and under what conditions they do not add to the development of
the assessment.
f.
Techniques for identifying and discriminating among different types of
stress must be developed. There was concern that the exposure assessment
should consider other sources of a particular stressor (such as
contamination or changes to sediment grain size) which may be impacting
chemical or physical conditions at the management sites. The USACE
should develop or provide guidance for operations personnel to use in
trying to discriminate among sources.
Workgroup Participants
Sabine Apitz
Pat Deliman
Arnold Bierschenk
Bridgette Deshields
Drew Carey
Bob Engler
John Clayton
David Glaser
Jerry Cura - Co-Chair
Frank Gobas
12
Chapter 2 Exposure Assessment Workgroup Summary
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us - Support Integrated Publishing |
