Interview with Dr. Jules Blais

Jules M. Blais is a biogeochemist and ecotoxicologist who studies sources and pathways of persistent pollutants such as organochlorine pesticides, polychlorinated biphenyls (PCBs) and trace metals like mercury in aquatic environments. Jules M. Blais, PhD Associate Professor Department of Biology, University of Ottawa, 30 Marie Curie Road, Rm. 271 Ottawa, Ont. K1N 6N5,Canada.

Email: jblais@science.uottawa.ca
Web: http://www.bio.uottawa.ca/scripts/mbr-e.php?id=2
Laboratory: http://www.science.uottawa.ca/lancet/

1. How is the Arctic unique with respect to the accumulation of contaminants?
   
   The Arctic tends to accumulate persistent semivolatile chemicals like organochlorine pesticides and PCBs because these chemicals tend to evaporate in warm environments, and they tend to condense and concentrate in cold environments, making the Arctic a natural sink for these chemicals. Colder temperatures may also enhance preservation of these chemicals. In addition, these chemicals tend to concentrate in foodchains because they are taken up efficiently from digestion and are only eliminated from the body very slowly. As a result, high concentrations of these chemicals are sometimes observed in marine mammals and seabirds that are near the top of a long complex foodchain.
   
   

2. Are there any other factors beside seabird influence which may be contributing to the contaminant level of these high Arctic ponds?

   Seabirds are likely to be the dominant sources of persistent bioaccumulative toxicants (like methyl mercury, organochlorine compounds, etc.) in these ponds. Concentrations of these chemicals in sediments near the cliffs where the seabirds are nesting are 10 to 70 times higher than in sediments from ponds unaffected by seabirds. Independent tracers of seabird influence (nitrogen, phosphorus, cadmium, dissolved organic carbon) corroborate our conclusion that the contaminants in these ponds are derived from seabirds. However, for the contaminants to have entered the seabirds, they would have had to be transported by air and ocean currents to the locations where the seabirds derive the bulk of their nutrition. We know that these seabirds derive their nutrition mainly in Jones Sound and Baffin Bay.

3. What are some limitations of this study?
   
   There are several things we still don't know about contaminant transfer to the coastal Arctic. We have only studied this phenomenon in one location so far in the Canadian Arctic, though there are indications that similar responses are occurring in the Norwegian Arctic (at Bear Island, for example). We also don't know the extent to which these chemicals will accumulate in the aquatic and terrestrial foodchains.

4. How is human health affected by the high level of contaminants in these remote areas? (How are they exposed? What are the implications of exposure?)
   
   We are not sure of the role of contaminant biotransport by seabirds as vectors for human exposure. There has been extensive research done on human exposure to chemicals in the Arctic, with indications that humans may be adversely affected by these chemicals. For example, persistent organic pollutants like PCBs and methyl mercury are thought to affect neural development and the immune system. As a result, their abundance in certain northern traditional foods may lead to IQ deficits and higher incidences of infections.

5. Will greater understanding of the mechanism of pollution transport in the Arctic have any implications for developing strategies to protect humans from these chemicals?
   
   I believe so. For example, arctic research on contaminants has already been instrumental in developing legislation to restrict and ban the worst of these chemicals, such as the Stockholm Convention on Persistent Organic Pollutants, a legally binding international treaty overseen by the United Nations Environment Programme.

6. What was the biggest challenge in conducting this study?
   
   The biggest challenge was the logistics of doing research in such a remote setting. Arctic research requires a great deal of planning and patience.