Subsistence hunting of the bowhead whale (Balaena mysticetus) is still a viable part of the socioeconomic structure of coastal Alaskan Eskimo people. Accordingly, oceanic pollution has increasingly become a concern to these people over the last decade. This concern has also become relevant to various government agencies. The possibility of the bioaccumulation of marine contaminants, especially heavy metals in the edible tissues of the bowhead whale might pose a threat to the health status of those people consuming tissues from exposed species. We have determined the levels of eight heavy metals (As, Cd, Cu, Fe, Hg, Pb, Se, Zn) in five tissues (blubber, visceral fat, muscle, kidney, liver) of 41 bowhead whales taken by subsistence hunters in the period from 1983-1990. The determined levels were compared to World Health Organization (WHO) Provisional Tolerable Weekly Intake (PTWI) values to determine the maximum quantities of tissue which could be consumed weekly without exceeding the WHO/PTWI levels.

Tissues were obtained from the Department of Wildlife Management of the North Slope Borough in Barrow, Alaska under a National Marine Fisheries Service Permit. Specimens were labeled, frozen and shipped to Texas A&M University. Specimens were trimmed to avoid possible field contamination, digested in nitric acid and analyzed by atomic absorption spectrophotometry. Accuracy and precision of data were determined through the use of replicate samples, internal standardization, sample spikes, National Bureau of Standards reference materials and the bracketing of actual samples between appropriate blanks and standard curves.

We found that accumulation of most metals was highest in the liver with the exception of Cd which was found to have highest levels in the kidney. Furthermore, there was a strong correlation between the levels of Hg and Se determined in liver. These trends are in accordance with the other reports of levels found in other Mysticetes as well as in odontocetes. Metal levels that we determined generally occurred within the ranges documented in other cetacean species. According to our data, Hg intake from traditional dietary habits would not be likely to exceed WHO guidelines; however, levels of bowhead kidney Cd were sufficiently high to result in excessive Cd intake if kidney is frequently consumed as part of their diet.