Deka-BDE: At the instigation of the Norwegian Pollution Control Authority (SFT), the Norwegian Polar Institute has analysed the content of the hazardous substance deca-BDE in glaucous gulls. Additionally, new analyses carried out by the National Veterinary Institute of Norway/Norwegian School of Veterinary Science for the first time show that deca-BDE is also found in polar bears.

Surprising long-range transport
The results are worrying researchers because there are no known sources of deca-BDE in the Arctic, and because it was believed that the substance could not be transported over long distances. An SFT investigation in 2003 discovered deca-BDE in moss. These findings gave the first indication of atmospheric transport, and therefore the possibility of long-range transport.

This was highly surprising, and was received with interest when the results were presented to the EU. The fact that the substance has now been found in the Arctic is further indication that deca-BDE can be transported over long distances. 

Bioaccumulation
In theory, deca-BDE should not accumulate in the food chain (be bioaccumulated) due to its properties, but many recent findings indicate that the substance can be bioaccumulated after all. The Norwegian Polar Institute, working along with Canadian laboratories, has analysed a range of hazardous chemicals found in blood and eggs from glaucous gulls, and deca-BDE was among the chemicals which were detected. Prior to this, deca-BDE was also found in birds of prey in Sweden (in peregrine falcons and sparrowhawks).

Deca-BDE in samples from polar bears
The National Veterinary Institute of Norway/Norwegian School of Veterinary Science has carried out analyses of samples from eight polar bears from Svalbard. The samples were taken during the period 2001–2003. The levels of deca-BDE are low, but detectable. These discoveries in polar bears reinforce the evidence that the substance can be bioaccumulated in the food chain.

Measures under consideration
The substance is being considered under the EU’s programme for risk assessment, and the Norwegian results with glaucous gulls and polar bears are part of the basis for their decision. At the same time the EU is working on measures to reduce emissions, and on the basis of these latest findings the EU should also consider a ban.

Both Norway and the EU have passed bans on the use and sale of the two most dangerous brominated flame retardants, penta- and octa-BDE, from 1st July (Norway) and 15th August 2004 (EU) respectively.

Effects uncertain
An experiment has shown behavioural changes in mice, which gives cause for concern, but these results are highly controversial. There are also results which indicate that deca-BDE can be broken down into other chemicals including penta- and octa-BDE.

Important to act quickly
Previous experience with PCBs shows that it takes a long time from the banning of a substance until the concentrations in nature are reduced. Even though penta- and octa-BDE are now banned, it may be many years before we see positive results from such measures in the form of reduced levels in the Arctic. In the meantime we can expect that the levels in the Arctic will increase. 

Further reading        

• SFT’s work with brominated flame retardants (in Norwegian)      
• The Norwegian Polar Institute