HBCD, hexabromocyclododecane, is a much-used flame retardant in insulating foam and furniture upholstery. It disrupts the thyroid function and the functioning of the nervous system in mammals. The researchers only found the alpha isomer of HBCD in the blubber of porpoises and dolphins. Boon's team were Bart Zegers from the Institute for Biodiversity and Ecosystem Dynamics (Universiteit van Amsterdam), Timo Hamers from the Institute for Environmental Studies (Vrije Universiteit Amsterdam) and Graham Pierce from the University of Aberdeen.
The porpoises and dolphins investigated were stranded on the coasts of Scotland, Ireland, the Netherlands, Belgium, France and northwest Spain. By far the most HBCD was found in the blubber of animals from the Irish Sea and the West Coast of Scotland. Therefore the researchers suspect that this HBCD originates from a source discharging into the Irish Sea.
The alpha isomer of HBCD forms at most fifteen percent of the HBCD formulation used in commercial flame retardants. The three isomers differ in how the bromine atoms are bound to the carbon atoms of HBCD and a new analytical technique can distinguish between the different isomers. Using this technique, Boon and his colleagues discovered that only the alpha isomer accumulates in sea mammals such as dolphins. They used liver material from laboratory rats and a recently dead seal washed up on a beach
Contact: Dr Jan P. Boon
Netherlands Organization for Scientific Research