[Peculiarities of exposure to polychlorinated biphenyls (PCBS) in the indigenous population of the coastal and mainland Chukotka].

The indigenous people of coastal areas show a low percentage of low chlorinated and dioxin-like PCB congeners (as opposed to mainland aborigines) with a significant proportion of the "triad" in the amount of PCBs. 5 years after the first survey the ratio of the analyzed groups of PCB congeners in the blood of parturients - mothers, as well as in the fetus - child in the coastal Chukotka remained unchanged, indicating that the equal share rate of clearance-accumulation of congeners and is almost equal share content of PCB congeners in the mother and child. The average duration of half-lives of PCB congeners (#105-187) from the mother's body was 4-6 years (for the sum of PCBs - 5.7 years), which is broadly consistent with the results of foreign studies. The composition of PCB congeners in the blood of the continental population significantly differs from those in the food, while coastal residents--similar to the composition of PCBs in marine mammals. The content of PCB congeners in the domestic sources of pollution has no resemblance to the composition of PCBs in the blood of the natives.

[Specificity of exposure of the indigenous dwellers of coastal and inland Chukotka to dichlorodiphenyltrichloroethane].

In the indigenous dwellers of coastal Chukotka, blood DDT levels are 1.5-2 times higher than those of continental areas, which is due to the higher global DDT pollution of a sea food chain. The blood levels of 4,4-DDE in the reproductive-age women of coastal Chukotka are comparable to those in other Russian Arctic regions, slightly lower than in Greenland, but essentially higher than in Canada, Alaska and Scandinavian countries. Blood DDE/DDT ratio in the coastal indigenous dwellers is almost twice higher than that in the inland inhabitants, which is indicative of the "older" exposure of coastal people to DDT. There was an about equal (70-75%) decrease in 4,4-DDE and 4,4-DDT levels with a practically invariable ratio (12-15) and a nearly equal elimination half-life period (about 3.5 years) in the mothers of coastal Chukotka 5 years after the first examination. The elevated 4,4-DDE/4,4-DDT ratios in the tissues of sea mammals generally correspond to higher isomer ratios in the blood of coastal natives and relatively low 4,4-DDE/4,4-DDT ratios in the venison, fowl, and fish predetermine lower ratios in the blood of inland inhabitants. The extremely low of DDE/DDT ratio (0.4) in the washouts and scrapes from the kitchen walls of dwellings are conclusively associated with the recent application of DDT as a household insecticide.

[Correlation between the receptor specificity of pandemic influenza A (H1N1)pdm09 virus strains isolated in 2009-2011 and the structure of the receptor-binding site and the probability of fatal primary viral pneumonia].

The receptor specificity (RS) of pandemic influenza A(H1N1) pdm09 virus strains deposited into the State Collection of Viruses of the Russian Federation, D. I. Ivanovsky Research Institute of Virology, Ministry of Health and Social Development of Russia, in the 2009-2010 and 2010-2011 epidemic seasons to a panel of 9 sialoglycopolymers (SGP). The strains were divided into 3 groups according to the W(3/6) index proposed by the authors, which was equal to the amount of reactivities to unbranched alpha2-3-SGP to that of reactivities to unbranched alphal-6-SGP: W(3/6) < or = 1.0; 1.0 < W(3/6) < or = 1.5. The W(3/6) < or = 1.5 group showed a predominance of a2-3-RS, attended by the high incidence of fatal primary viral pneumonias (FPVP) (60.0%) and amino acid replacements in the HA1 receptor-binding site (RBS) (80.0%): D222{G, N} and Q223R. The 1.0 < W(3/6) < or = 1.5 group was characterized by mixed alpha2-3/alpha2-6-RS with the incidence of FPVP (29.7%) and amino acid replacements in the HA1 RBS (40.5%) (D222{G, N, V} and Q223), respectively. In the W(3/6) < or = 1.0 group, alpha2-6-RS was prevalent, FPVPs were absent and amino acid replacements in HA1 RBS (D222{G, E}) were seen only in 6.0% of cases. The number of strains with increased specificity to alpha2-3-sialosides increased in the 2010-2011 epidemic season as compared to the previous season. With their further spread among the population, there may be a rise in cases of severe primary viral pneumonias with possible fatal outcomes, which can be, however, accompanied by a decrease in the capacity of mutants to air-dropwise transmission.

[The blood levels of stable toxic substances in the native residents of costal Chukotka and their children's infection morbidity].

A considerable reduction in the blood levels of stable organic pollutants (SOP) has been noted in the mothers of native ethnicities of costal Chukotka during a 5-year period, which may be accounted for by certain purification of food chains, altered diet with emphasis on delivered products, and long-term breastfeeding. The elevated level of SOP in children from birth to age 5 years is explained by long-term breastfeeding and the early consumption of local foods. The content of heavy metals (mercury and lead) in both maternal and children's blood has unchanged for 5 years. The children's infection morbidity has been quite high; at the same time no associations of the children's blood levels of toxic substances with the incidence of infectious diseases have been found. However, two children maximally exposed to SOP and metals have been observed to be rarely susceptible to diseases.

[Blood heavy metals in women of indigenous ethnic groups in the Far North].

The paper presents the results of an investigation of the blood levels of mercury, lead, and cadmium in women of indigenous ethnic groups in the Far North. A certain correlation was found between the higher incidence of some poor pregnancy outcomes and fetal maldevelopment upon increased maternal exposure to heavy metals. The found correlations were statistically insignificant. There was no significant association of female exposure to heavy metals with menstrual irregularities and the sex ratio of neonates.

[Reduction of a risk of the deleterious effects of persistent toxic substances on the health of the far north population].

The paper presents the general principles and procedure of the development and implementation of measures to decrease and prevent environmental pollution with persistent toxic substances (PTS) in the Russian Arctic and, accordingly, to reduce a risk of the deleterious effects of PTS on human health. Based on the results of a study of PTS in the Russian Arctic (from the Kola Peninsula to Chukotka), the authors first systematized the basic lines and actions and formulated specific measures to reduce the North population's exposure to PTSs, such as polychlorinated biphenyls, organic chlorine pesticides (dichlorodiphenyltrichloroethane, hexachlorocyclohexane, hexachlorobenzene, etc.), and heavy metals (mercury, lead, cadmium). A package of measures is aimed at maximally reducing the presence of PTS-containing objects and materials in the north (via detection, collection, and extermination), at neutralizing the soils in settlement lands, at setting up safe water consumption systems, at organizing effective control over the safe use of chemicals and the levels of PTS in raw food materials and foodstuffs, and at working out recommendations on safe procedures for food purchase, storage, and cooking.

Nutrition of Chukotka Native children.

We estimated nutrient and food intakes of adolescents aged 14 to 17 who inhabit the coastal and tundra zones of the Chukotka Autonomous Region, Russia, and developed approaches to improving their diet. We reassessed the dietary intakes of Native (n = 162) and non-Native (n = 155) adolescents of both sexes. We found that mean energy and nutrient intakes (protein, fat, carbohydrates) among schoolchildren were similar in different ethnic and sex groups. The diet of the subjects studied is high in sugar (18-19% of energy) and has an unfavorable fat composition, with saturated fatty acids (SFAs) contributing 14-15% of energy, and polyunsaturated fatty acids (PUFAs) contributing 5-6% of energy. Our results demonstrate that the children's diet approaches that of "Western society" to a greater extent than that of adults. A program on nutrition based on the national government project "Children of the North" has been developed at the Institute of Internal Medicine in collaboration with the Chukotka Sanitary and Epidemiology Supervision Services. This program includes the list of food products recommended for children. Some ecological factors and ethnic idiosyncrasies are considered.

[The spread of the principal socially important parasitic disease on the territory of the Chukot Autonomous Okrug (ChAO)]. / O rasprostranenii osnovnykh sotsial'no znachimykh parazitarnykh boleznei na territorii Chukotskogo Avtonomnogo Okruga (ChAO).

The paper provides the examination findings of helminthiases in the population of the town of Anadyr, the settlements of Kanchalan, Krasneno, and in the reindeer-breeding teams of the Anadyr District, CAD. The children infected with enterobiasis were shown to amount to 15.1 to 22.9%, diphyllobothriasis was detected in 12.9 - 33.7% of the examinees. Single cases of ascariasis were revealed. Analysis of 232 cases with echinococcosis demonstrates that the infection is prevalent over the whole Chukotka territory. Infection with Echinococcus multilocularis is more common in the indigenous population in the north-east of the District and that with Echinococcus granulosus in the central and northern regions. High extensive and intensive parasitic contamination rates of environmental objects, such as soil, sewage, household appliances, fish, etc., were noted, indicating a constant risk for Chukotka population's infection with parasites.