New organic contaminants detected in the Arctic
The chemicals are added to plastic products and electric equipment etc., and are found far away from the actual site of the source. This indicates that the chemicals are long-range transported by air and sea currents in the same way as other POPs.
What is NILU`s task in this connection?
One main task of NILU in the Polar Environmental Centre in Tromsø is to study organic contaminants in Arctic. Ivan C. Burkow, informs that the human society is exposed to thousands of different chemicals every day. This itself is not necessarily an environmental problem. However it is clear that the knowledge about the lifetime in the environment and possible effects on the immune system, the risk of cancer, reproduction as well as learning ability is often very limited for many of these compounds. One of the compound groups that have been in focus lately is the group of bromin ated flame retardants.
Investigations performed by NILU reveal the presence of these contaminants in environmental samples. NILU has, in collaboration with institutions in the Polar Environmental Centre, analysed samples from different marine animals in Arctic. Considerable levels of some of the brominated flame retardants are detected in fat tissues, though the levels are lower than for PCB and certain insecticides. These results are in agreement with similar studies from Sweden and Canada. Burkow tells that from the present scientific knowledge it is difficult to judge if these compounds are a danger for the environment, but the levels in the environment are increasing. Analysis of brominated flame retardants in blood-samples from people from Northern Norway, reveal the presence of this environmental pollutant group. The causal connection for these levels are not clear, but will be further investigated by NILU in collaboration with the University of Tromsø.
What is the origin of these compounds?
Brominated flame retardants (BFR) are today extensively used in a variety of industrial and consumer products such as textiles, polymeric materials and electrical equipment. BFRs are either covalently bound or used as an additive to the material, and BFRs from the latter group can more easily migrate into the environment. The annual production and the variety of compounds in use have drastically increased during the last few years. In 1992 there was a world production of approximately 150 000 tons yearly, while the yearly production in 2000 is suggested to be 250 000 tons, which is 20 % of the world production of flame retardants.
The group of brominated flame retardants consists of many differntcompounds. Polybrominated diphenylethers (PBDE) and polybrominated biphenyls (PBB), belongs to the group of additive flame retardants that more easily migrate into the environment. The other main group, containing among others tetrabromobisphenole-A (TBBPA) and its derivatives, are more strongly bound to protect the material from burning. Approximately 1/3 of the global production consists of TBBPA and its derivatives, PBDE just below 1/3 while other brominated compounds are responsible for the rest. The production of PBBs today is minimal.
How is it possible that these compounds are detected in Arctic, thousands of kilometres from the sources?
The presence of these compounds in the Arctic environment far away from the actual site of release or use, indicate that these compounds are transported by air and ocean to the northern regions like the other POPs. Since these compounds degrade very slowly and tend to bioaccumulate in the food chain we are able to detect them in Arctic environmental samples. Although investigations show an increased level in different environmental samples, our knowledge concerning brominated flame retardants in our geographical area is very limited.
Is there any health risks?
The consequences of brominated flame retardants on environment and human health is today not very well known. It is anyway assumed that these organic pollutants may be cancerogenic, endocrine disruptive and affect brain function. Similar to other POPs, these compounds are lipophilic, accumulate in the food-chain, and may be transferred through placenta to the embryo and to offspring during breastfeeding. In light of this, it is important to monitor these compounds in the environment and enlarge our knowledge of their potential biological effects.