Human exposure monitoring and evaluation in the Arctic: the importance of understanding exposures to the development of public health policy. (57/701)

Arctic indigenous peoples face significant challenges resulting from the contamination of Arctic air, water, and soil by persistent organic pollutants, heavy metals, and radionuclides. International cooperative efforts among governments and research institutions are under way to collect the information needed by environmental health scientists and public health officials to address environmental contamination in the Arctic. However, the climatic, political, and cultural conditions of the land and its native populations combine to present a unique set of scientific and logistic challenges to addressing this important public health issue. Public health officials have the responsibility to respect the cultural traditions of indigenous communities, while simultaneously designing strategies that will reduce their exposure to environmental contaminants and rates of disease and dysfunction. Researchers can better understand the link between environmental exposures and disease through monitoring programs for both the subsistence diets and health status of the indigenous populations. We suggest that the incorporation of community-based participatory research methods into programs designed to assess biomarkers of contaminant exposure in children and adults may be a valuable addition to ongoing and newly developed research programs. This approach could serve as a model for international environmental health initiatives, because it involves the participation of the local communities and seeks to builds trust between all stakeholders.  (+info)

Phylogenetic composition of Arctic Ocean archaeal assemblages and comparison with Antarctic assemblages. (58/701)

Archaea assemblages from the Arctic Ocean and Antarctic waters were compared by PCR-denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes amplified using the Archaea-specific primers 344f and 517r. Inspection of the DGGE fingerprints of 33 samples from the Arctic Ocean (from SCICEX submarine cruises in 1995, 1996, and 1997) and 7 Antarctic samples from Gerlache Strait and Dallman Bay revealed that the richness of Archaea assemblages was greater in samples from deep water than in those from the upper water column in both polar oceans. DGGE banding patterns suggested that most of the Archaea ribotypes were common to both the Arctic Ocean and the Antarctic Ocean. However, some of the Euryarchaeota ribotypes were unique to each system. Cluster analysis of DGGE fingerprints revealed no seasonal variation but supported depth-related differences in the composition of the Arctic Ocean Archaea assemblage. The phylogenetic composition of the Archaea assemblage was determined by cloning and then sequencing amplicons obtained from the Archaea-specific primers 21f and 958r. Sequences of 198 clones from nine samples covering three seasons and all depths grouped with marine group I Crenarchaeota (111 clones), marine group II Euryarchaeota (86 clones), and group IV Euryarchaeota (1 clone). A sequence obtained only from a DGGE band was similar to those of the marine group III Euryarchaeota:  (+info)

A population-based registry study of infant mortality in the Arctic: Greenland and Denmark, 1973-1997. (59/701)

OBJECTIVES: We sought to determine precise estimates of infant mortality rates and to describe overall trends in infant mortality in Greenland and Denmark from 1973 to 1997. METHODS: We analyzed data from population-based registries of all live-born infants in Greenland and Denmark to calculate infant mortality rates from 1973 to 1997. RESULTS: Between the periods of 1973-1977 and 1993-1997, neonatal mortality rates in Greenland declined from 20.9 per 1000 live-born infants to 15.7, and postneonatal mortality rates declined from 20.9 per 1000 to 5.9. Infant mortality rates were significantly higher in Greenland than in Denmark, and the excess mortality was uniformly distributed over all birthweight percentiles. In Greenland, the risk of infant death was significantly lower if the mother was born outside Greenland. CONCLUSIONS: Postneonatal mortality rates in Greenland have decreased significantly during the past 25 years, but little progress has been made in decreasing neonatal mortality rates. Disparities exist among children with different maternal origins.  (+info)

Conserved genetic basis of a quantitative plumage trait involved in mate choice. (60/701)

A key question in evolutionary genetics is whether shared genetic mechanisms underlie the independent evolution of similar phenotypes across phylogenetically divergent lineages. Here we show that in two classic examples of melanic plumage polymorphisms in birds, lesser snow geese (Anser c. caerulescens) and arctic skuas (Stercorarius parasiticus), melanism is perfectly associated with variation in the melanocortin-1 receptor (MC1R) gene. In both species, the degree of melanism correlates with the number of copies of variant MC1R alleles. Phylogenetic reconstructions of variant MC1R alleles in geese and skuas show that melanism is a derived trait that evolved in the Pleistocene.  (+info)

Lack of HTLV-I carriers in the Sami, an ethnic group living in the Arctic area in Norway. (61/701)

The Sami is an ethnic group with ill-defined genetic origins, living in the northern areas of the Scandinavian Peninsula and Russia. Distinct from other European populations in culture and language, they are generally deemed to be remote from the Caucasian lineage. In order to ascertain whether the Sami are genetically linked to Asiatic Mongoloids, we investigated serological markers of human T-cell leukemia virus type I (HTLV-I) infection. Particle agglutination tests for serum HTLV-I antibody were performed for 400 Sami living in Finnmark, the northernmost county of Norway, and in 380 Caucasians (or Norse) in the same region, using serum samples collected for the purpose of studying cardiovascular disease among Northland people in 1974-75. One sample from a Sami showed a tentatively positive reaction, and 4 sera from Sami and 4 from Norse individuals exhibited non-specific agglutination. However, none of the 9 sera showed a positive result in western blotting for HTLV-I proteins, namely, gp46, p53, p24, and p19. Since HTLV-I is distributed most prevalently among northern and southwestern Japanese in Asia and Andeans in South America, the absence of HTLV-I in the Sami might suggest their genetic remoteness from these ethnic groups.  (+info)

Molecular evidence links cryptic diversification in polar planktonic protists to Quaternary climate dynamics. (62/701)

It is unknown how pelagic marine protists undergo diversification and speciation. Superficially, the open ocean appears homogeneous, with few clear barriers to gene flow, allowing extensive, even global, dispersal. Yet, despite the apparent lack of opportunity for genetic isolation, diversity is prevalent within marine taxa. A lack of candidate isolating mechanisms would seem to favor sympatric over allopatric speciation models to explain the diversity and biogeographic patterns observed in the oceans today. However, the ocean is a dynamic system, and both current and past circulation patterns must be considered in concert to gain a true perspective of gene flow through time. We have derived a comprehensive picture of the mechanisms potentially at play in the high latitudes by combining molecular, biogeographic, fossil, and paleoceanographic data to reconstruct the evolutionary history of the polar planktonic foraminifer Neogloboquadrina pachyderma sinistral. We have discovered extensive genetic diversity within this morphospecies and that its current "extreme" polar affinity did not appear until late in its evolutionary history. The molecular data demonstrate a stepwise progression of diversification starting with the allopatric isolation of Atlantic Arctic and Antarctic populations after the onset of the Northern Hemisphere glaciation. Further diversification occurred only in the Southern Hemisphere and seems to have been linked to glacial-interglacial climate dynamics. Our findings demonstrate the role of Quaternary climate instability in shaping the modern high-latitude plankton. The divergent evolutionary history of N. pachyderma sinistral genotypes implies that paleoceanographic proxies based on this taxon should be calibrated independently.  (+info)

Arctic indigenous peoples experience the nutrition transition with changing dietary patterns and obesity. (63/701)

Indigenous Peoples globally are part of the nutrition transition. They may be among the most extreme for the extent of dietary change experienced in the last few decades. In this paper, we report survey data from 44 representative communities from 3 large cultural areas of the Canadian Arctic: the Yukon First Nations, Dene/Metis, and Inuit communities. Dietary change was represented in 2 ways: 1) considering the current proportion of traditional food (TF) in contrast to the precontact period (100% TF); and 2) the amount of TF consumed by older vs. younger generations. Total diet, TF, and BMI data from adults were investigated. On days when TF was consumed, there was significantly less (P < 0.01) fat, carbohydrate, and sugar in the diet, and more protein, vitamin A, vitamin D, vitamin E, riboflavin, vitamin B-6, iron, zinc, copper, magnesium, manganese, phosphorus, potassium, and selenium. Vitamin C and folate, provided mainly by fortified food, and fiber were higher (P < 0.01) on days without TF for Inuit. Only 10-36% of energy was derived from TF; adults > 40 y old consistently consumed more (P < 0.05) TF than those younger. Overall obesity (BMI > or = 30 kg/m(2)) of Arctic adults exceeded all-Canadian rates. Measures to improve nutrient-dense market food (MF) availability and use are called for, as are ways to maintain or increase TF use.  (+info)

Plutonium in the arctic marine environment--a short review. (64/701)

Anthropogenic plutonium has been introduced into the environment over the past 50 years as the result of the detonation of nuclear weapons and operational releases from the nuclear industry. In the Arctic environment, the main source of plutonium is from atmospheric weapons testing, which has resulted in a relatively uniform, underlying global distribution of plutonium. Previous studies of plutonium in the Kara Sea have shown that, at certain sites, other releases have given rise to enhanced local concentrations. Since different plutonium sources are characterised by distinctive plutonium-isotope ratios, evidence of a localised influence can be supported by clear perturbations in the plutonium-isotope ratio fingerprints as compared to the known ratio in global fallout. In Kara Sea sites, such perturbations have been observed as a result of underwater weapons tests at Chernaya Bay, dumped radioactive waste in Novaya Zemlya, and terrestrial runoff from the Ob and Yenisey Rivers. Measurement of the plutonium-isotope ratios offers both a means of identifying the origin of radionuclide contamination and the influence of the various nuclear installations on inputs to the Arctic, as well as a potential method for following the movement of water and sediment loads in the rivers.  (+info)