The Biology of Bioavailability: The Role of Functional Ecology in Exposure Processes
Technical Report,01 Jan 2013,01 Jan 2015
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS VICKSBURG
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The research objective was to improve accuracy of sediment exposure assessments by considering the functional ecology of benthic organisms and different exposure routes sediment particles, pore water, overlying water. Laboratory experiments were conducted using four marine invertebrates a worm, two amphipods, and a clam. Organisms were exposed to two different contaminated sediments within mesocosms designed to assess polychlorinated biphenyl PCB exposure from overlying water and whole sediment using pathway isolation chambers. The impacts of two sediment remediation methods were also tested 1 a 2 cm sand cap and 2 activated carbon AC that was not aggressively mixed with sediment prior to organism testing to simulate a field deployment. Porewater concentrations were assessed using polyethylene devices PEDs and provided a reasonable indicator of organism exposure but did not account for organisms with connections to the overlying water and direct particle ingestion. The sand cap significantly reduced PCB exposure for all the species except the clam while non-equilibrated AC did not result in significant reductions in bioaccumulation. These results can be used to design functional bioavailability assessments and provide basis for future guidance. Data were used to enhance the capability and predictive reliability of an existing modeling framework RECOVERY.
- Physical and Dynamic Oceanography
- Organic Chemistry