Universal thermal climate index in the Arctic in an era of climate change: Alaska and Chukotka as a case study.

The modern unambiguous climate change reveals in a rapid increase of air temperature, which is more distinctly expressed in the Arctic than in any other part of the world, affecting people health and well-being. The main objective of the current research is to explore the inter- and intra-annual changes in thermal stress for people in the Arctic, specifically for two parts of Beringia: Alaska, USA, and Chukotka, Russia, using climatology of the universal thermal climate index (UTCI). Data for 39 locations are taken from the ERA5-HEAT reanalysis for the period 1979-2020. Climatologically, the study area is divided into four subregions in Alaska: North, Interior, West and South, and two in Chukotka: Interior and Coast. The extreme coldest UTCI categories (1 and 2) are most common in coastal locations of northern Alaska and Chukotka, where strong winds exacerbate the low temperatures during winter. The results show that the frequency of category 1 (UTCI<-40°C) varies spatially from a quarter of all hours annually in Alaska North to almost zero in Alaska South. On the other hand, the warmest categories are rarely reached almost everywhere in Alaska and Chukotka, and even categories 7 and 8 (UTCI between +26 and +38°C) are found occasionally only at interior locations. Category 6 with no thermal stress (UTCI between +9 and+26°C) has frequencies up to 3% and 25% in Alaska North and Interior, respectively. The extremely cold thermal stress frequencies have substantially decreased over the 1979-2020 period, especially in Alaska North and Chukotka Coast. At the same time, the number of hours with UTCI in the comfortable category of thermal perception has increased depending on subregion, from 25 to 203 h/year. Overall, a decrease in the UTCI categories of extremely cold stress is coupled with an increase in the comfortable range in both Alaska and Chukotka. The salient conclusion is that, from the point of view of comfort and safety, global warming has a positive impact on the climatology of thermal stress in the Arctic, providing advantages for the development of tourism and recreation.

Organochlorine Pollutants in Human Breast Milk from North of the Far Eastern Region of Russia.

The widespread application of pesticides in the territories of the former USSR still exerts negative impacts on their ecological status. In this regard, dedicated programs for monitoring persistent organic pollutants (POP) in humans are implemented in several countries. Our study aimed to assess the accumulation of organic pollutants in breast milk of women residing the Chukotka Autonomous Okrug (CAO). Organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) concentrations in breast milk samples were measured by gas chromatography-mass spectrometry (GC-MS). The POP concentrations in the samples varied from 13 ng/g lipid weight (lw) to 620.6 ng/g lw (median 58.3 ng/g lw). An assessment of health risk to infants fed breast milk from CAO women did not show any exceedance of the estimated daily intake (EDI). The results obtained are the indirect evidence of the presence of these compounds in the environment and their negative effects on ecosystems and human health.

Solving the mystery of the Chukotka stinky gray whales.

Gray whales (Eschrichtius robustus) constitute an important part of the diet of Chukotka Native population, reaching 30% of consumed food for the inland Chukchas. Over one hundred licenses for whale hunting are issued on an annual basis. After the USSR collapse natives had to hunt whales near the shore from the small boats. The problem of "stinky" whales arose immediately, as the meat of some harvested species possessed a strong medicinal/chemical odour. The hypotheses explaining the phenomenon ranged from biotoxins, to oil spills. To understand the problem, various tissues of normal and stinky Gray whales were collected in 2020-2021 and analyzed using headspace solid phase microextraction with Gas Chromatography - Mass Spectrometry. Here, we show that dozens of smelly organic compounds were identified among over 500 compounds detected in the samples. The most interesting analytes related to the off odour are bromophenols. The most probable suspect is 2,6-dibromophenol with strong iodoformic odour, perfectly matching that of the "stinky" whales. Quantitative results demonstrated its levels were up to 500-fold higher in the "stinky" whales' tissues. The source of 2,6-dibromophenol is likely polychaetes, producing 2,6-dibromophenol and colonising near shore waters where whales feed. Therefore, the mystery of the stinky whales may be considered resolved.

Annual variation in waterbird clutch initiation date in relation to spring thaw in Arctic Russia.

To test for the degree of species-specific variation in clutch initiation date in relation to spring thaw, we recorded first egg dates in 1433 nests of seven large bodied long-distance migratory waterbird species breeding on Ayopechan Island in the Chaun Delta, Chukotka, in the Russian Arctic during 2002-2020. Pacific Loon Gavia pacifica, Sandhill Crane Grus canadensis and Glaucous Gull Larus hyperboreus all adjusted timing of clutch initiation completely to annual variation in first frost-free dates. First egg dates of Spectacled Eider Somateria fischeri also significantly advanced in warmer springs, but the rate of change was significantly less than unity, implying a reduced capacity to accommodate change in vernal thaw that may not be able to keep up with greater change in the future. Long-tailed Duck Clangula hyemalis and Vega Gull Larus vegae showed a tendency for earlier first egg dates in years with earlier first frost-free date, but for both species, the relationship failed to reach statistical significance. Bewick's Swan Cygnus columbianus showed almost no change in mean first egg date across the observed variation in first frost-free dates. Based on these data, we suggest that while all seven species showed signs of plasticity in their timing of onset of breeding, Pacific Loon, Sandhill Crane and Glaucous Gull showed greater adaptability to adjust the timing of their breeding season to recent variation in spring thaw than the other four species studied here over this period.

Features of Occupational Health Risks in the Russian Arctic (on the Example of Nenets Autonomous Okrug and Chukotka Autonomous Okrug).

Working in the Arctic increases the risk of occupational diseases, which is especially important in the context of acute shortage of manpower in the region. The purpose of the study was to comparatively evaluate the working conditions and occupational pathology in Nenets Autonomous Okrug (NAO) and Chukotka Autonomous Okrug (ChAO) of Russia. We analyzed the results of socio-hygienic monitoring "Working Conditions and Occupational Morbidity" in 2008-2018. Despite similar climatic and socio-economic conditions, significant differences exist in the health risks of the working populations of the two regions. In NAO two-thirds of workers were employed at facilities with satisfactory sanitary and epidemiological well-being, while in ChAO only 13% of workers had such conditions. In NAO, almost all occupational diseases (93.2%) were due to exposure to noise among civil aviation workers. In ChAO, health problems mainly occurred among miners (81.5%). The most common of these were noise effects on the inner ear (35.2%), chronic bronchitis (23.1%), and mono- and polyneuropathies (12.5%). In 2008-2018, the occupational pathology risk in ChAO was higher than in NAO: RR = 2.79; CI 2.09-3.71. Thus, specificity of technological processes and forms of labor organization create significant differences in health risks for workers. It is necessary to use modern mining equipment to decrease the occupational morbidity in ChAO. In NAO, this effect can be achieved by updating the fleet of civil aviation.

Hot in Cold: Microbial Life in the Hottest Springs in Permafrost.

Chukotka is an arctic region located in the continuous permafrost zone, but thermal springs are abundant there. In this study, for the first time, the microbial communities of the Chukotka hot springs (CHS) biofilms and sediments with temperatures 54-94 °C were investigated and analyzed by NGS sequencing of 16S rRNA gene amplicons. In microbial mats (54-75 °C), phototrophic bacteria of genus Chloroflexus dominated (up to 89% of all prokaryotes), while Aquificae were the most numerous at higher temperatures in Fe-rich sediments and filamentous "streamers" (up to 92%). The electron donors typical for Aquificae, such as H2S and H2, are absent or present only in trace amounts, and the prevalence of Aquificae might be connected with their ability to oxidize the ferrous iron present in CHS sediments. Armatimonadetes, Proteobacteria, Deinococcus-Thermus, Dictyoglomi, and Thermotogae, as well as uncultured bacteria (candidate divisions Oct-Spa1-106, GAL15, and OPB56), were numerous, and Cyanobacteria were present in low numbers. Archaea (less than 8% of the total community of each tested spring) belonged to Bathyarchaeota, Aigarchaeota, and Thaumarchaeota. The geographical location and the predominantly autotrophic microbial community, built on mechanisms other than the sulfur cycle-based ones, make CHS a special and unique terrestrial geothermal ecosystem.

Arenimonas fontis sp. nov., a bacterium isolated from Chukotka hot spring, Arctic region, Russia.

A moderately thermophilic, neutrophilic, aerobic, Gram-negative bacterium, strain 3729kT, was isolated from a thermal spring of the Chukotka Peninsula, Arctic region, Russia. It grew chemoorganoheterotrophically, utilizing proteinaceous substrates, including highly rigid keratins as well as various polysaccharides (glucomannan, locust bean gum, gum guar and xanthan gum). The major fatty acids of strain 3729kT were iso-C15 : 0 (60.9%), iso-C17 : 0 (12.0%), C16 : 0 (9.9%) and iso-C16 : 0 (7.4%). Isoprenoid quinones were Q-8 (95%) and Q-9 (5%). The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine and three unidentified polar lipids. Strain 3729kT was inhibited by chloramphenicol, neomycin, novobiocin, kanamycin, tetracycline, ampicillin and polymyxin B, but resistant to rifampicin, vancomycin and streptomycin. At the same time, strain 3729kT inhibited growth of Micrococcus luteus and its genome possessed genes for antimicrobial activity against Gram-positive bacteria (a single putative bacteriocin and several secreted lysozymes and peptidoglycan lytic transglycosylases). The DNA G+C content was 69.8 mol%. 16S rRNA gene sequence-based phylogenetic analysis placed strain 3729kT into a distinct species/genus-level branch within the family Xanthomonadaceae (Proteobacteria). Phylogenetic analysis of 120 conservative protein sequences of all Xanthomonadaceae with validly published names and publicly available genomic sequences supported a species-level position of strain 3729kT within the genus Arenimonas. Pairwise ANI values between strain 3729kT and other Arenimonas species were of 75-80 %, supporting the proposal of a novel species. Accordingly, Arenimonas fontis sp. nov., with the type strain 3729kT (=VMK В-3232Т=DSM 105847T), was proposed.

Tepidiforma bonchosmolovskayae gen. nov., sp. nov., a moderately thermophilic Chloroflexi bacterium from a Chukotka hot spring (Arctic, Russia), representing a novel class, Tepidiformia, which includes the previously uncultivated lineage OLB14.

A novel aerobic moderately thermophilic bacterium, strain 3753OT, was isolated from a Chukotka hot spring (Arctic, Russia) using the newly developed technology of laser engineering of microbial systems. Сells were regular short rods, 0.4×0.8-2.0 µm in size, with a monoderm-type envelope and a single flagellum. The temperature and pH ranges for growth were 42-60 °C and pH 6.5-8.5, the optima being 50-54 °C and pH 7.3. Strain 3753OT grew chemoorganoheterotrophically on a number of carbohydrates or peptidic substrates and volatile fatty acids, and chemolithoautotrophically with siderite (FeCO3) as the electron donor. The major cellular fatty acid was branched C19 : 0. Phosphatidylethanolamine, phosphatidylglycerol and two unidentified phospholipids as well as two yellow carotenoid-type pigments were detected in the polar lipid extract. Strain 3753OT was inhibited by chloramphenicol, polymyxin B, vancomycin, streptomycin, neomycin and kanamycin, but resistant to the action of novobiocin and ampicillin. The DNA G+C content was 69.9 mol%. The 16S rRNA gene as well as 51 conservative protein sequence-based phylogenetic analyses placed strain 3753OT within the previously uncultivated lineage OLB14 in the phylum Chloroflexi. Taking into account the phylogenetic position as well as phenotypic properties of the novel isolate, the novel genus and species Tepidiforma bonchosmolovskayae gen. nov., sp. nov., within the Tepidiformaceae fam. nov., the Tepidiformales ord. nov. and the Tepidiformia classis nov. are proposed. The type strain of Tepidiforma bonchosmolovskayae is 3753OT (=VKM B-3389T=KTCT 72284T).

Nienna chukotka sp. nov. (Protura, Acerentomidae, Nipponentominae) from the Arctic region, with a key to species of the genus.

A new species of Nienna was collected in the most northern part of the Palearctic, inside the Arctic Circle. In possessing seta Pc on tergite VII and sternites VI-VII and a very long foretarsal sensillum a, Nienna chukotka sp. nov. is more similar to Alaskaentomon species than to the other Nienna species distributed in southern Siberia and northern China. The new species differs from nearly all other members of Nipponentominae in possessing five anterior setae on tergite VII and in the presence of posterolateral pores on tergite I, as in members of Hesperentomon (Hesperentomidae). An identification key to Nienna species is provided.

Health Risk Modifiers of Exposure to Persistent Pollutants among Indigenous Peoples of Chukotka.

The aim of the study was to assess temporal trends in health risks related to most common persistent contaminants, including polychlorinated biphenyls (PCBs), dichloro-diphenyl-trichloroethanes (DDTs), lead (Pb), as well as mercury (Hg) among indigenous peoples living in coastal areas of Chukotka in Arctic Russia. This is examined in relation to exposure pathways and a range of social and behavioral factors capable of modifying the exposure to these contaminants, including place of residence, income, traditional subsistence, alcohol consumption, and awareness of risk prevention. The primary exposure pathway for PCBs is shown to be the intake of traditional foods, which explained as much as 90% of the total health risk calculated employing established risk guidelines. Nearly 50% of past DDT-related health risks also appear to have been contributed by contaminated indoor surfaces involving commonly used DDT-containing insecticides. Individuals who practiced traditional activities are shown to have experienced a 4.4-fold higher risk of exposure to PCBs and a 1.3-fold higher risk for DDTs, Pb, and Hg. Low income, high consumption of marine mammal fat, alcohol consumption, and lack of awareness of health risk prevention are attributed to a further 2- to 6-fold increase in the risk of PCBs exposure. Low socioeconomic status enhances the health risks associated with exposure to the persistent contaminants examined.

Traditional Diet and Environmental Contaminants in Coastal Chukotka II: Legacy POPs.

The article is the second in the series of four that present the results of a study on environmental contaminants in coastal Chukotka, conducted in the context of a multi-disciplinary investigation of indigenous foodways in the region. The article presents the results of the analysis of legacy Persistent Organic Pollutants (POPs) found in the samples of locally harvested food and indoor matters, collected in 2016 in coastal Chukotka. Temporal trends and circumpolar comparisons of POPs in food have been carried out. Estimated daily intakes (EDIs) of POPs by local food consumption were calculated based on the food intake frequencies (questionnaire data). Concentrations of the studied legacy POPs in marine mammal blubber were relatively high (up to 100⁻200 µg/kg ww) but not exceeding the allowable limits. Gray whale blubber and whale mantak were the most contaminated foods, followed by the ringed, spotted and bearded seal blubber, then by walrus blubber and fermented walrus (deboned walrus parts aged in subterranean pits, typically over a period of 6 months). At the backdrop of general decrease or invariability (compared to the previous coastal Chukotka study 15 years ago) of the majority of POPs, an increasing tendency of HCB, mainly in marine mammals, were noted. Legacy POPs in marine mammals sampled in Chukotka were generally much lower than in those sampled in Alaska and northern Canada. We suggest that the Alaska Coastal Current from the Bering Sea plays a major role in this phenomenon. Analyses of the additional sources of in-home food contamination (home-brewed alcohol, domestic insecticides) have revealed relatively high levels of HCHs, DDTs and PCBs, which still represent a share of dietary exposure of local people to POPs.

Traditional Diet and Environmental Contaminants in Coastal Chukotka III: Metals.

The article is the third in the series of four that present the results of a study on environmental contaminants in coastal Chukotka, which was conducted in the context of a multi-disciplinary investigation of indigenous foodways in the region. The article presents the results of the analysis of metals found in the samples of locally harvested terrestrial, freshwater, and marine biota collected in 2016 in coastal Chukotka. For some species of local fauna and flora, the metals content was demonstrated for the first time. Lead and Hg were low in all foods, while As concentrations were up to four mg/kg ww in fish and marine mammals blubber. Wild plants showed accumulations of Mn (up to 190 mg/kg ww), Al (up to 75 mg/kg ww), Ni, Ba, and Sr. Seaweed contained high levels of As (14 mg/kg) and Sr (310 mg/kg); ascidians (sea squirts) contained Al (up to 560 mg/kg), Cr, and Sr; and blue mussels contained Cd (2.9 mg/kg) and Al (140 mg/kg). Exceedances over the Russian allowable levels were revealed for As, Cd, and Al in different food items. Absence of the established limits for Al and Sr in seafood, and Mn in wild plants and berries, impedes the determination of excess levels. Temporal trends and geographic comparisons of metals in foods have been carried out. The estimated daily intakes (EDIs) of metals by local food consumption were calculated based on the food intake frequencies. Follow-up (15 years after the first study) analyses of Hg, Pb, and Cd concentrations in local foods has not revealed any increase, while a slight decrease tendency was noted for some of the metals in several foods.

Traditional Diet and Environmental Contaminants in Coastal Chukotka IV: Recommended Intake Criteria.

The article is the last in the series of four that present the results of a study on environmental contaminants in coastal Chukotka, conducted in the context of a multi-disciplinary investigation of Indigenous foodways in the region. The article presents the Recommended Food Daily Intake Limit (RFDIL) guidelines of the locally harvested foods in coastal Chukotka. The guidelines were developed based on the results of the analysis of the legacy persistent organic pollutants (POPs) and metals found in the samples of locally harvested food, which was collected in 2016 in the villages of Enmelen, Nunligran, and Sireniki on the south coast of the Chukchi Peninsula, Russian Arctic. The overall aim of the article is to expand the toolset for dealing with the challenges of: (1) setting the dietary recommendations when we assess multiple contaminants in a variety of foods (and our method of RFDILs calculation is an example of a possible approach), and (2) managing the real-life circumstances when many types of foods are mixed in many dishes regularly and the concentrations of contaminants in these mixed dishes become uncertain. Drawing on perspectives from the fields of environmental health sciences, humanities, social sciences, and visual art, the authors consider the RFDILs of the examined foods in the context of the culinary practices and aesthetics values (those that relate to the culturally held ideas of beauty ascribed to a dish or the processes of its preparation and consumption) of the Indigenous Arctic cuisine in the region of the Bering Strait, and in the broader dynamics of food and culture.

Traditional Diet and Environmental Contaminants in Coastal Chukotka I: Study Design and Dietary Patterns.

The article is the first in the series of four that present the results of a study on environmental contaminants in coastal Chukotka, conducted in the context of a multi-disciplinary investigation of indigenous foodways in the region of the Bering Strait. We provide an overview of the contemporary foodways in our study region and present the results of the survey on the consumption of locally harvested foods, carried out in 2016 in the Chukotkan communities of Enmelen, Nunligran, and Sireniki. The present results are evaluated in comparison to those of the analyses carried out in 2001⁻2002 in the village of Uelen, located further north. Where appropriate, we also draw comparative insight from the Alaskan side of the Bering Strait. The article sets the stage for the analyses of legacy persistent organic pollutants (POPs) and metals to which the residents become exposed through diet and other practices embedded in the local foodways, and for the discussion of the Recommended Food Daily Intake Limits (RFDILs) of the food that has been sampled and analyzed in the current study.

Drivers of maternal accumulation of organohalogen pollutants in Arctic areas (Chukotka, Russia) and 4,4'-DDT effects on the newborns.

BACKGROUND: One of the most worrying consequence of the production and use of persistent organohalogen pollutants (POPs) is the high accumulation in Arctic populations because of long-range transport. Study of the effects in these populations may illustrate human impacts that are difficult to assess in other locations with lower exposure to these compounds and more diverse pollutant influences. OBJECTIVE: We aimed to identify the main maternal characteristics influencing on the accumulation of these compounds and the effects on the newborns in a highly exposed Arctic population (Chukotka, Russia). METHODS: Organochlorine and organobromine compounds were analysed in maternal venous serum (n = 250). The study included data on residence, educational level, age, parity and body mass index (BMI) from self-reported questionnaires and measured anthropometric characteristics of newborns. RESULTS: Concentrations of ß-hexachlorocyclohexanes, hexachlorobenzene, 4,4'-DDT and polychlorobiphenyls were high when compared with those generally found in adult populations later than year 2000. The polybromodiphenyl ethers were negligible. These POP concentrations were higher than in Alaska and Arctic Norway and similar to those in Canada. The Chukotka mothers living in inland areas showed significant lower concentrations than those living in the coast (p < 0.001) except for 4,4'-DDT. The population from the Chukotsky District, a specific coastal area, showed the highest concentrations. Residence was therefore a main concentration determinant (p < 0.001) followed by maternal age, and in some cases parity and BMI (p < 0.05). 4,4'-DDT showed an association with the anthropometric characteristics of the newborns (p < 0.05). Mothers with higher 4,4'-DDT concentrations had longer gestational ages and gave birth to infants with higher weight and length. CONCLUSIONS: The maternal accumulation patterns of POPs were mainly related with residence. Most of these compounds were found in higher concentration in women living at coastal areas except 4,4'-DDE and 4,4'-DDT which were of inland origin. This last pesticide was the pollutant showing positive associations with gestational age and newborn's weight and length. To the best of our knowledge, this is the first study reporting statistically significant associations between maternal 4,4'-DDT exposure and anthropometric characteristics of the newborns.

Public Health Practice Report: water supply and sanitation in Chukotka and Yakutia, Russian Arctic.

Information from 2013-2015 have been analysed on water accessibility, types of water service to households, use of water pretreatment, availability of sewerage, use of sewage treatment in Chukotka Autonomous Okrug and Yakutia Republic, based on evaluation information accessible in open sources, such as regional statistics and sanitary-epidemiologic reports. The main causes of the poor state of water supply and sanitation in the study regions include: very limited access to in-home running water (one-quarter of settlements in Chukotka and half of settlements in Yakutia have no regular water supply) and lack of centralised sewerage (78% and 94% of settlements correspondingly have no sewerage); lack of water pretreatment and sewage treatment, outdated technologies and systems; serious deterioration of facilities and networks, frequent accidents; secondary pollution of drinking water. Lack of open objective information on Russian Arctic water supply and sanitation in the materials of the regional and federal statistics hampers the assessment of the real state of affairs. The situation for water and sanitation supply in these Russian Arctic regions remains steadily unfavourable. A comprehensive intervention from national and regional governmental levels is urgently needed.

Naukan ethnobotany in post-Soviet times: lost edibles and new medicinals.

BACKGROUND: This study focuses on health-related plant use among speakers of the critically endangered Naukan language (Inuit-Yupik-Unangan family) in the Russian Far East. The Naukan people were forced, in 1958, under Soviet consolidation, to move from their original settlement on Cape Dezhnev, leading to significant changes in spiritual worldview, subsistence, social structure, and language proficiency in the years that followed. Here, we focus on changes that elders report in their edible, medicinal, and spiritual uses of local plant species since their childhood. METHODS: The authors worked from 2014 to 2016 in the villages of Lavrentiya, Lorino, and Uelen, in the Chukotskiy district of the Chukotka autonomous region, directly adjacent to the Bering Strait. We conducted structured interviews, using an oral history approach, along with participant observation and collection of voucher specimens from the local arctic tundra. Those with Naukan names and uses represent 42 species in 25 families. RESULTS: Participants reported a decrease of 13% in the number of edible species that people currently harvest, from what they recall harvesting in their youth. On the other hand, the number of local species considered to be medicinal has actually increased by 225%. Current and past Naukan medicinal practices diverge in some notable ways from those of neighboring societies on the Alaskan side of the Bering Strait. Most of the spiritual significance of local plants species is remembered by only a few elders. CONCLUSIONS: Naukan elders explained the large increase in use of medicinal plants by noting that their original concept of medicine emphasized prevention and that illnesses were often assigned a spiritual rather than physical cause. Increased integration with ethnic Russians after moving from Naukan led to the adoption not only of new plant uses, but also of an entirely different, more naturalistic way of viewing illness and treatment.

Mitochondrial phylogeography of a Beringian relict: the endemic freshwater genus of blackfish Dallia (Esociformes).

Mitochondrial genetic variability among populations of the blackfish genus Dallia (Esociformes) across Beringia was examined. Levels of divergence and patterns of geographic distribution of mitochondrial DNA lineages were characterized using phylogenetic inference, median-joining haplotype networks, Bayesian skyline plots, mismatch analysis and spatial analysis of molecular variance (SAMOVA) to infer genealogical relationships and to assess patterns of phylogeography among extant mitochondrial lineages in populations of species of Dallia. The observed variation includes extensive standing mitochondrial genetic diversity and patterns of distinct spatial segregation corresponding to historical and contemporary barriers with minimal or no mixing of mitochondrial haplotypes between geographic areas. Mitochondrial diversity is highest in the common delta formed by the Yukon and Kuskokwim Rivers where they meet the Bering Sea. Other regions sampled in this study host comparatively low levels of mitochondrial diversity. The observed levels of mitochondrial diversity and the spatial distribution of that diversity are consistent with persistence of mitochondrial lineages in multiple refugia through the last glacial maximum.

Cancer mortality in the indigenous population of coastal Chukotka, 1961-1990.

OBJECTIVES: The general aim was to assess the pattern and trend in cancer mortality among the indigenous people of coastal Chukotka during the period 1961-1990. METHODS: All cases of cancer deaths of indigenous residents of the Chukotsky district in the north-easternmost coast of Chukotka Autonomous Okrug were copied from personal death certificates. There were a total of 219 cancer deaths during the study period. The average annual number of cases, percent, crude, and age-standardized cancer mortality rates (ASMR) per 100,000 among men and women for all sites combined and selected sites were calculated. Data were aggregated into six 5-year periods to assess temporal trends. Direct age-standardization was performed with the Segi-Doll world standard population used by the International Agency for Research on Cancer. RESULTS: The indigenous Chukchi and Eskimo people living in Chukotsky district were at higher risk of death from cancer during the 30-year period between 1961 and 1990, with ASMR among men twice that of Russia, and among women 3.5 times higher. The excess can be attributed to the extremely high mortality from oesophageal cancer and lung cancer. CONCLUSIONS: The indigenous people of coastal Chukotka were at very high risk of death from cancer relative to the Russian population nationally. The mortality data from this study correspond to the pattern of incidence reported among other indigenous people of the Russian Arctic. Little information is available since 1990, and the feasibility of ethnic-specific health data is now severely limited.

Cancer incidence and mortality in Chukotka, 1997-2010.

OBJECTIVES: The general aim was to assess cancer incidence and mortality among the general population of Chukotka in 1997-2010 and to compare it with the population of Russia. METHODS: Cancer data were abstracted from the annual statistical reports of the P.A. Hertzen Research Institute of Oncology in Moscow. The annual number and percent of cases, crude and age-standardized cancer incidence (ASIR) and mortality (ASMR) rates per 100,000 among men and women in the Chukotka Autonomous Okrug were determined for the period 1997-2010 for incidence and 1999-2010 for mortality. Two years' data were aggregated to generate temporal trends during the period. In age-standardization, the Segi-Doll world standard population used by the International Agency for Research on Cancer was used. RESULTS: The higher incidence and mortality rate of cancer (all sites combined) among men compared to women, which was observed in Russia nationally, was reflected also in Chukotka, although the difference between men and women was not statistically significant. Overall, the patterns of cancer sites are similar between Chukotka and Russia, with cancer of the lung/trachea/bronchus and stomach occupying the top ranks among men. Oesophageal cancer is common in Chukotka but not in Russia, whereas prostate cancer is common in Russia but not in Chukotka. Among women, breast cancer is either the commonest or second commonest cancer in terms of incidence or mortality in both Chukotka and Russia. Cancer of the lung/trachea/bronchi ranks higher in Chukotka than in Russia. The rate of cancer incidence and mortality for all sites combined during the 13-year period was relatively stable in Russia. Dividing the period into two halves, an increase among both men and women was observed in Chukotka for all sites combined, and also for colorectal cancer. CONCLUSIONS: This paper presents previously unavailable cancer epidemiological data on Chukotka. They provide a basis for comparative studies across circumpolar regions and countries. With its small population, cancer rates in Chukotka tend to be highly unstable and fluctuate widely from year to year. Even when aggregated over a decade or more, only broad conclusions regarding patterns and trends can be made regarding some of the commonest cancer sites, or with all sites combined. Chukotka experienced substantial social and economic dislocations during the period under study, which could conceivably affect risk factor distribution and the quality of medical care.