Biomedical subjects

Rebecca S Pugh

Publications and source records attributed to Rebecca S Pugh.

4 recordsLinked to original sources

PubMed2006

Development of a murre (Uria spp.) egg control material.

The Seabird Tissue Archival and Monitoring Project (STAMP) is a collaborative Alaska-wide effort by the US Fish and Wildlife Service's Alaska Maritime National Wildlife Refuge (USFWS/AMNWR), the US Geological Survey's Biological Resources Division (USGS/BRD), the Bureau of Indian Affairs Alaska Region Subsistence Branch (BIA/ARSB), and the National Institute of Standards and Technology (NIST) to monitor long-term (decadal) trends in environmental contaminants using seabird eggs. To support this effort, a matrix- (seabird egg) and concentration-specific control material was needed to ensure quality during analytical work. Although a herring gull egg quality assurance (HGQA) material is available from Environment Canada (EC), contaminant concentrations in this material tended to be higher than those observed in Alaskan murre (Uria spp.) eggs. Therefore, to prepare a more appropriate control material, a total of 12 common murre (U. aalge) and thick-billed murre (U. lomvia) eggs from four Bering Sea and Gulf of Alaska nesting locations were cryohomogenized to create 190 aliquots each containing approximately 6 g. This new control material was analyzed by different methods at NIST and EC facilities for the determination of concentrations and value assignment of 63 polychlorinated biphenyl (PCB) congeners, 20 organochlorine pesticides, and 11 polybrominated diphenyl ether (PBDE) congeners. The total PCB concentration is approximately 58 ng g(-1) wet mass. Results obtained for analytes not listed on the certificates of analysis of the previously used control materials, HGQA and NIST's Standard Reference Material (SRM) 1946 Lake Superior Fish Tissue, are also presented.

Alaska↗

PubMed2006

Murre eggs (Uria aalge and Uria lomvia) as indicators of mercury contamination in the Alaskan marine environment.

Sixty common murre (Uria aalge) and 27 thick-billed murre (Uria lomvia) eggs collected by the Seabird Tissue Archival and Monitoring Project (STAMP) in 1999-2001 from two Gulf of Alaska and three Bering Sea nesting colonies were analyzed for total mercury (Hg) using isotope dilution cold vapor inductively coupled mass spectrometry. Hg concentrations (wet mass) ranged from 0.011 microg/g to 0.357 microg/g (relative standard deviation = 76%), while conspecifics from the same colonies and years had an average relative standard deviation of 33%. Hg levels in eggs from the Gulf of Alaska (0.166 microg/g +/- 0.011 microg/g) were significantly higher (p < 0.0001) than in the Bering Sea (0.047 microg/g +/- 0.004 microg/g). Within the Bering Sea, Hg was significantly higher (p = 0.0007) in eggs from Little Diomede Island near the arctic than at the two more southern colonies. Although thick-billed and common murres are ecologicallysimilar,there were significant species differences in egg Hg concentrations within each region (p < 0.0001). In the Bering Sea, eggs from thick-billed murres had higher Hg concentrations than eggs from common murres, while in the Gulf of Alaska, common murre eggs had higher concentrations than those of thick-billed murres. A separate one-way analysis of variance on the only time-trend data currently available for a colony (St. Lazaria Island in the Gulf of Alaska) found significantly lower Hg concentrations in common murre eggs collected in 2001 compared to 1999 (p = 0.017). Results from this study indicate that murre eggs may be effective monitoring units for detecting geographic, species, and temporal patterns of Hg contamination in marine food webs. The relatively small intracolony variation in egg Hg levels and the ability to consistently obtain adequate sample sizes both within and among colonies over a large geographic range means that monitoring efforts using murre eggs will have suitable statistical power for detecting environmental patterns of Hg contamination. The potential influences of trophic effects, physical transport patterns, and biogeochemical processes on these monitoring efforts are discussed, and future plans to investigate the sources of the observed variability are presented.

Alaska↗

PubMed2005

Factors influencing persistent organic pollutant concentrations in the Atlantic white-sided dolphin (Lagenorhynchus acutus).

Assessing the trends of persistent organic pollutants (POPs) in cetaceans is difficult because of age and gender influences on accumulation. Persistent organic pollutants bioaccumulate and are poorly metabolized; hence, concentrations may increase with age in males while females reduce their POP burden through parturition and lactation. Age and gender effects on contaminant concentrations are species specific because of life history and reproductive strategies. These influences must be understood in order to elucidate and assess lifetime POP exposure. The objectives of this study were to determine baseline POP concentrations in blubber samples from the Atlantic white-sided dolphin (Lagenorhynchus acutus) and to investigate life history and other influences, such as metabolism, on these concentrations. Forty-seven L. acutus blubber samples collected from mass stranding events in Massachusetts, USA (1993-2000), and archived in the National Marine Mammal Tissue Bank at the National Institute of Standards and Technology (Gaithersburg, MD, USA) were analyzed for 55 polychlorinated biphenyl congeners (PCB; 55 congeners), five polybrominated diphenyl ether (PBDE) congeners, and organochlorine pesticides (toxaphene, DDT and metabolites, mirex, dieldrin, chlordanes, hexachlorocyclohexanes, hexachlorobenzene, and endosulfans) by gas chromatography/mass spectrometry (GC-MS). Ages for 19 animals were determined from growth layer groups on decalcified, stained thin tooth sections. Total PCBs (sigmaPCB; sum of 55 congeners) were the contaminants present in the highest concentrations in all age classes (0.5-63 microg/g wet mass) followed by sum of DDTs (0.50-43 microg/g wet mass), toxaphene (0.055-31 microg/g wet mass), chlordanes (0.30-24 microg/g wet mass), and PBDEs (0.12-4.0 microg/g wet mass). Body length had a greater statistical influence than age on contaminant burdens in L. acutus. Contaminant burdens decreased with length in both male and female L. acutus, suggesting metabolic elimination and/or growth dilution in males and off-loading via lactation in females.

Adipose Tissue↗

PubMed2004

Persistent organic pollutants in Alaskan murre (Uria spp.) eggs: geographical, species, and temporal comparisons.

Concentrations of persistent organic pollutants (POPs) in eggs of common and thick-billed murres (Uria aalge and U. lomvia) from five Alaskan nesting colonies were dominated by 4,4'-DDE, total polychlorinated biphenyls (totalPCBs; 46 congeners comprised mainly of PCB congeners 153, 118, 138, 99, and 151), hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), and chlordane compounds (totalCHL). Concentrations of 4,4'-DDE, cis-nonachlor, and heptachlor epoxide were lower than those reported for some of the same colonies in the 1970s, while HCB concentrations were similar. In general, significantly higher concentrations were found in eggs from Gulf of Alaska colonies compared to those from Bering Sea colonies except for HCB (higher in the Bering Sea) and beta-HCH (no significant difference between the two regions). Thick-billed murre eggs contained higher concentrations of 4,4'-DDE and totalPCBs, whereas common murre eggs had higher HCB concentrations. Possible factors contributing to the POPs patterns found in eggs from these murre colonies are discussed.

Alaska↗