PW10 Bioaccumulation and Biomagnification
Exhibit Hall
8:00 AM - Wednesday
(PW173) In situ bioaccumulation testing and the determination of invertebrate biota-sediment accumulation factors for PCBs and PAHs.
Bowersox, M1, Barbour, C1, Diamond, J1, 1 Tetra Tech, Inc., Owings Mills, MD, USA
ABSTRACT- In situ bioaccumulation testing using Lumbriculus variegatus was performed at six locations on three tidal freshwater mudflats of the Delaware River to determine biota-sediment accumulation factors (BSAF) to be used in ecological risk assessment. Four mud flat sampling locations, in close proximity to a Superfund site near Philadelphia, PA (2 near-field and 2 mid-field) and two reference locations (far-field) were established, each with six replicate test chambers. L. variegatus were exposed in situ to the sediment in perforated 4" diameter PVC tubes covered by 100-
m mesh for approximately 28 days. Following exposure, concentrations of PCB congeners and PAHs were measured in the worm tissue and sediment. PCB congener concentrations in worms ranged from 3 - 100 times the surrounding sediment concentration indicating biomagnification, with PCB 105, 114, and 123 resulting in highest mean BSAFs (6.3, 8.2, and 101.1 respectively). Near-field locations had sediment concentrations of PCBs and PAHs approximately 10 times the measured concentrations at mid-field and far-field loactions. On average, worm BSAFs for the 12 dioxin-like PCB congeners were fairly similar across sampling locations (4.1 - 7.9), which was expected based on the similarity in the types of PCB congeners across locations. These BSAF values were very consistent with other invertebrate BSAFs reported for the Delaware River (mean BSAF=4.5). The in situ method was successful in containing the worms as well as providing adequate exposure to the sediments being tested. BSAF data collected in this study demonstrates that invertebrates living in the sediments near the site are likely to accumulate high concentrations of PCBs and PAHs, which will then be available to higher trophic levels of fish and wildlife.
Key words: PCB, bioaccumulation, PAH, sediment