HP6 Emerging Pollutants
202 Oregon Ballroom
1:20 PM - 5:20 PM, Thursday
() Geochemistry and bioavailability of decabromodiphenyl ether in the Chesapeake Bay estuary.
Klosterhaus, S.1, Baker, J.1, 1 University of Maryland Chesapeake Biological Laboratory, Solomons, Maryland, USA
ABSTRACT- Ongoing risk assessments are lacking data from which to estimate the potential transfer of the widely used, extremely hydrophobic flame retardant decabromodiphenyl ether (Deca-BDE) from its repository in sediments to aquatic food chains. Our objectives for this study were (1) to investigate the steady-state partitioning behavior of BDEs in bulk sediments by comparing relative congener abundances in sediment and pore water, and (2) to compare these profiles with those found in the biota to provide insight into the relative importance of each exposure route in the accumulation of BDEs by benthic organisms. Bulk sediment and infaunal invertebrates were collected from sites along a spatial gradient downstream from a wastewater treatment facility (WWTF) in Back River and sites adjacent to Hart-Miller Island, a confined sediment disposal facility at the mouth of Back River (Baltimore, Maryland, USA). BDE concentrations decreased downstream from the wastewater facility, with total BDE concentrations in sediments ranging from 50-9000 ng/g dry weight and Deca-BDE accounting for 93-99% of the total BDE at all sites. Relative concentrations among the BDE congeners detected in sediment near the WWTF were 209>208>206>207>196>197,47, 99. Total BDE concentrations in pore water were <10 ng/liter, and Deca-BDE was detected at only one site. Total BDE concentrations in the invertebrates ranged from 20-475 ng/g lipid, with BDEs 47 and 99 predominating. Our results indicate that Deca-BDE does not significantly accumulate in the species examined in this study. Clearly, BDEs are strongly sorbed to sediment particles, suggesting a very low exposure of BDEs to infaunal invertebrates via pore water at our study sites.
Key words: bioavailability, PBDE, porewater, benthos