ARCUS Student Award | 3rd Annual Award
3rd Annual ARCUS Award for Arctic Research Excellence
|Submitted by:||Kimberlee B. Beckmen|
|Author:||Kimberlee B. Beckmen, Gina M. Ylitalo, Rodney G. Towell, Margaret M. Krahn, Todd M. O'Hara, and John E. Blake|
|Title:||Factors affecting organochlorine contaminat concentrations in milk and blood of northern fur seal (Callorhinus ursinus) dams and pups from St. George Island, Alaska|
|Affiliation:||Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska|
Levels of organochlorine contaminants in blood of northern fur seal (Callorhinus ursinus) pups and the blood and milk of their dams early in the lactation period are reported here. The contaminants included 14 selected individual polychlorinated biphenyl (PCB) congeners and DDT metabolites identified through high-performance liquid chromatography. Congeners CB-77, -126, and -189 were below the limits of detection in milk and blood samples analyzed. Congener specific concentrations of PCBs in the blood of pups were compared based on the age of their dam (5 years or younger, or more than seven years). Pups of young dams (presumably primiparous) had significantly elevated levels of CBs-101, -118, -128, -138, -153/87, -170/194, and -180 than pups of older dams (multiparous). Congeners CP-128 and &endash;170/194 were detected in the blood of pups of young dams but not in the blood of pups of older dams or in any of the dam's blood. Additionally, pups had higher blood levels of 8 of 8 PCB congeners as compared to the blood of dams and 7 of 10 congeners measured in milk when adjusted for lipid content. Levels of DDT metabolites and toxic equivalency quotients of dioxin-like congeners followed similar trends. Lipid-normalized concentrations of CB-101 and total CBs were significantly higher in the blood of dams than in the milk. CB-128, -156, -157, -170/194, p,p'-DDT, o,p'-DDT, p,p'-DDD, and o,p'-DDD were not detected in dam blood samples, but were detected in milk samples. Calculation of "biomagnification factors" from milk to pup blood indicated a biomagnification of CB-101, -105, -118, -138, -153/87, and -180. Significant mean accumulation factors ranging from 1.5 to 7.5. Inter-annual differences in exposure levels and specific congener concentrations in both milk and blood were apparent. Northern fur seal pups, especially first-born, have a substantial exposure to organochlorine contaminants at a critical developmental stage.