"NUTRITIOUS AND SAFE" RESEARCH: BOWHEADS SHOW LITTLE CONTAMINATION FROM TOXIC METALS
By Duncan Adams
Arctic Sounder

BARROW- A study funded by the North Slope Borough suggests that people who have eaten meat & blubber of bowhead whales in recent years have not consumed unhealthy levels of potentially toxic metals. A separate study, funded by the National Oceanic and Atmospheric Administration and the U.S. Department of Energy, suggests that bowhead whales and other Arctic animals in the Beaufort Sea and northern Alaska also seem to be relatively free of significant contamination from radioactive materials.

Although scientists caution that further sampling and monitoring must occur, a recently published study funded by the borough concluded that for most metals examined there is no concern about human consumption of meat or blubber from bowheads of Bering Sea stock. In addition, the study found no evidence that the metals are having adverse impacts on the whale. The one exception noted by the study was cadmium, which researchers warned can accumulate in the liver and kidneys of older whales.

Research is continuing as scientist sample the whales for heavy metals, as well as “radionuclides,” - a type of atom that exhibits radioactivity - to monitor their presence in the animals and to determine whether these contaminants cause cellular changes in the whales. Early indications from this ongoing research are encouraging.

From 1983-90 (except for 1985), biologists or technicians from the borough’s Department of Wildlife Management collected samples from 41 bowhead whales. The whales had been killed by Native hunters during the spring and fall subsistence whaling seasons. Biologists sampled liver, muscle, kidney, blubber and abdominal fat.

They were frozen and express shipped to the College of Veterinary Medicine at Texas A&M University, where researchers tested the tissues for the presence and levels of eight metals - arsenic, cadmium, copper, iron, mercury, lead, selenium and zinc. A report detailing the finding of the research was mailed to 150 whaling captains.

During a recent interview, Todd O'Hara, D.V.M., Ph.D., a research biologist for the borough’s wildlife department, discussed the report. “The good news is that a lot of the metals we would be concerned about being toxic were at very low levels. There was one metal found at moderately high level, and that was cadmium in the kidney, and we're continuing on with work to address that.”

Chronic exposure to cadmium has been linked to increased risk for lung and prostrate cancer. Studies have found also that cigarette smoking is a significant source of exposure to cadmium. Cadmium occurs naturally in the Arctic ecosystem. Like other metals, it is added to ecosystems by human industrial activities. The study did not attempt to specify the source of the metals detected in the tissues of the bowhead whales studied.

Meanwhile, the study found that “none of the metals studied were high enough in muscle, blubber or (abdominal) fat to pose a risk to human consumers. Lead, mercury and arsenic levels were very low in all tissues sampled in all animals.” The report’s summary concluded: “...these data indicate that in relation to metals, the tissues from bowhead are, in general, nutritious and safe to consume. It is also indicated that the bowhead whale has little metal contamination as compared to other examined Arctic marine mammals, except for cadmium, which requires further investigation as to its role in human and bowhead health.”

Sampling and research began again in the mid-1990s, when funding from NOAA and DOE allowed the Wildlife Department to participate in a study of radionuclide contamination in the bearded seal, the polar bear and the bowhead whale.

The scientists studied “anthropogenic” radionuclides - “man-made” radioactive materials - potentially present in the Arctic because of nuclear bomb testing as associated fallout, the dumping of radioactive materials in the Arctic Ocean by the former Soviet Union, the nuclear reactor accident in April 1986 at Chernobyl and other events.

Issued in July by Los Alamos National Laboratory, a report of the results of that study also suggests that residents of the North Slope can consume traditional foods from marine mammals without worrying about the foods’ contamination by radioactive materials.

According to the report, “The anthropogenic radionuclide concentrations in fish, birds and mammals were very low. Assuming that ingestion of food is an important pathway leading to human contact with radioactive contaminants and given dietary patterns in coastal Arctic communities, it can be surmised that marine food chains presently aren't significantly affected.”

Finally, O'Hara and Tom Albert, V.M.D., Ph.D., senior scientists for the borough’s wildlife department, received funding from the Office of Naval Research to continue both the metals research and the investigation of anthropogenic radionuclides.

Meanwhile, scientists from the North Slope and elsewhere will be back on the sea ice this spring, asking permission of whaling captains to take additional tissue samples from bowhead whales their crews have harvested.

For more information visit the ANI web site at http://www.alaska.net/~aknewspr/index.html