R6 PM Bioavailability
Thursday, 17 November 2005: 1:50 PM - 5:30 PM in 324-326

(TRI-1117-727466) A Chemical Approach for Assessing the Bioavailability of PCBs From Sediment.

Trimble, T, Lydy, M,

ABSTRACT- In order to accurately evaluate the risks posed by widespread PCB contamination, the degree of bioaccumulation in sediment-dwelling organisms must be determined. Although direct exposure experiments have commonly been conducted in the past to determine the bioavailability of contaminants from sediment to biota, a chemical method of determining bioavailability would be less expensive and less laborious. This study assesses the Tenax chemical extraction technique for determining bioavailability of PCBs from sediment and compares it to BSAFs (biota-sediment accumulation factors) determined using live organisms. The Tenax method will be evaluated for accuracy and predictability using a range of sediment types with differing organic carbon contents and sediment characteristics. Initial BSAFs from bioassays appear to be dependent on organic carbon (OC) content, with sediment containing approximately 150 ppb PCBs and 0.9% OC yielding a BSAF of 2.88 for total PCBs in Lumbriculus variegatus. Additional sediment BSAF data and Tenax bead results will be presented, with the majority of desorption to Tenax anticipated to occur within 6-10 hrs of contact with sediment.

Key words: tenax, pcbs, bioaccumulation, sediment