Levels of the flame retardants hexabromocyclododecane and tetrabromobisphenol A in the blubber of harbor porpoises (Phocoena phocoena) stranded or bycaught in the UK, with evidence for an increase in HBCD concentrations in recent years

Within the U.K. Marine Mammals Stranding Program, analysis of brominated flame retardants began in 1999. Initially, the focus of attention was the brominated diphenyl ethers. Since the withdrawal of the pentamix and octamix polybrominated diphenyl ether (PBDE) formulations from the EU market prior to August 2004, two other high-volume products, hexabromocycloclodecane (HBCD) and tetrabromobisphenol A (TBBP-A), have been included. We report the concentrations of these compounds in the blubber of harbor porpoises (Phocoena phocoena) stranded or dying due to physical trauma in the U.K. during the period 1994-2003. Analysis was undertaken using LC/MS method on a diastereoisomer basis. Eighty-five samples were analyzed for HBCD, and 68 of these for TBBP-A. alpha-HBCD dominated over the other isomers and was detected in all samples analyzed at concentrations ranging from 10 to 19 200 mu g kg(-1) wet weight. The maximum concentration was about double that reported in earlier U.K. studies. TBBP-A was detected in only 18 samples and at much lower concentrations, from 6 to 35 mu g kg(-1) wet weight. Investigation of possible time trends indicated a sharp increase in HBCD concentrations from about 2001 onward, which was not confounded by age (length), sex, nutritional status, or location. This may be a result of changing patterns of use of HBCD following limitations on the production and use of two PBDE formulations within the EU and will feed ongoing risk assessment activities.