Heavy metal accumulations in hair of northern fur seals: Application for biological monitoring

Hair of northern fur seals had the highest concentrations of many heavy metals among tissues and organs analyzed. Hair could be used as a sensitive indicator for its higher element levels, and can serve as a noninvasive technique for biological monitoring. Significant positive correlation were found between Hg in muscle, Fe in kidney and Cu in liver and those in hair of 42 fur seals from Off-Sanriku, Japan. Using age as a explanatory co-variables, significant multiple regression equations to estimate metal concentrations in internal organs by those in hair were obtained for Hg, Cd, Fe, Cu, Mn. To monitor the seasonal changes in hair concentrations, from the cervical region of 7 fur seals in the Otaru aquarium, Japan, guard hair were clipped during November, 1993 March, 1994 at 7 weeks intervals. Heavy metal levels in hair from the aquarium were compared with those collected in April, 1990--1991 from Off-Sanriku, Japan and from the Pribilof Islands, Alaska which were collected in July, 1992. The levels of Cu, Zn, Mn and Ni in hair in the captive seals gradually increased and were higher than those from Off-Sanriku. Those changes could be associated with growth of hair. In the hair of the breedingmore » animals collected from the island, concentrations of Mn, Ni and Fe were found to be significantly higher than those from Off-Sanriku. increased concentrations of Mn, Ni and Fe were supposed to be caused by exogenous contaminations derived from soil and blood. Fur seal hair seems to be an useful indicator to estimate the internal accumulations of heavy metals provided the seasonal changes and exogenous contamination are taken into account.« less