Bioaccumulation kinetics of brominated flame retardants (polybrominated diphenyl ethers) in blue mussels (Mytilus edulis)

Baltic Sea blue mussels, Mytilus edulis, were exposed to polybrominated dip henyl ethers (PBDEs, IUPAC congeners 47, 99, and 153) and polychlorinated b iphenyls (PCBs, congeners 31, 52, 77, 118, and 153) in a flow-through exper imental setup for 44 d. After the exposure phase, the mussels were allowed to depurate in natural brackish water for 26 d. After analyses, uptake clea rance rate coefficients (k(u)), depuration rate coefficients (k(d)), and bi oaccumulation factors (BAF) were calculated. A rapid uptake of all PBDEs an d PCBs was observed, especially for PBDE congeners 47 and 99 (k(a) 120 and 170 L/day/g dry weight, respectively). The depuration rare decreased with i ncreasing hydrophobicity as expected for the PCBs, bur for the PBDEs, depur ation rate coefficients appeared to be of the same magnitude for all three congeners independently of log K-ow. The BAFs obtained for PBDE 47 and PBDE 99 (1.3 x 10(6) and 1.4 x 10(6) ml/g dry weight, respectively) were higher than for all other substances in the study, severalfold higher than for PC Bs of similar hydrophobicity. The presented data indicate that the bioaccum ulation potential of PBDEs, extensively used as flame retardants, is simila r or higher than that of PCBs for filter feeding organisms such as blue mus sels.