Levels of polybrominated diphenyl ether flame retardants in sediment cores from Western Europe.

The levels of 14 brominated diphenyl ether (BDE)-congeners in sediment cores from three locations in Western Europe have been determined by GC/MS (negative chemical ionization mode). Sediments from the Drammenfjord (Norway), the western Wadden Sea (The Netherlands), and the freshwater Lake Woserin (Mecklenburg-Vorpommern, Germany) showed a time-dependent pattern in the distribution of BDEs since the beginning of the industrial production of polybrominated diphenyl ether (PBDE) formulations. Two out of three commercially available PBDE formulations could be distinguished.

Hepatic microsomal cytochrome P450 enzyme activity in relation to in vitro metabolism/inhibition of polychlorinated biphenyls and testosterone in Baltic grey seal (Halichoerus grypus).

Among other factors, cytochrome P450 (CYP) enzyme activity determines polychlorinated biphenyl (PCB) bioaccumulation, biotransformation, and toxicity in exposed species. We measured the oxidative metabolism in vitro of 12 PCB congeners, representing structural groups based on the number and position of the chlorine atoms, by the hepatic microsomes of one Baltic grey seal (Halichoerus grypus). Microsomal metabolism was observed for several PCBs with vicinal H atoms exclusively in the ortho and meta positions and without any ortho-Cl substituents (CB-15 [4,4'-Cl2] and CB-77 [3,3',4,4'-Cl4]), vicinal meta and para-H atoms (CB-52 [2,2',5,5'-Cl4], and -101 [2,2',4,5,5'-Cl5]) or with both characteristics in combination with either only one ortho-Cl (CB-26 [2,3',5-Cl3], CB-31 [2,4',5-Cl3]) or two ortho-Cl substituents (CB-44 [2,2',3,5'-Cl4]).

Levels of polybrominated diphenyl ether (PBDE) flame retardants in animals representing different trophic levels of the North Sea food Web.

The levels of individual PBDE congeners were investigated in the invertebrate species whelk (Buccinum undatum), seastar (Asterias rubens), and hermit crab (Pagurus bernhardus), the gadoid fish species whiting (Merlangius merlangus) and cod (Gadus morhua), and the marine mammal species harbor seal (Phoca vitulina) and harbor porpoise (Phocoena phocoena). These species are all important representatives of different trophic levels of the North Sea food web. All six major PBDE congeners detected (BDEs 28, 47, 99, 100, 153, and 154) are most prevalent in the commercial Penta-BDE formulation.