In the article, there have been presented literature data and given results of the authors’ own studies related to description of natural-climatic and anthropogenic health deterioration risk factors for population living in the Arctic. There have been singled out two main groups of risk factors specific for the Arctic regions.

AbstractThe peculiarity of natural conditions of Yakutia plays an important role in the formation of economic activities of its population. A significant number of rivers and lakes are a favorable condition for the development and preservation of traditional fishing. Currently, more than 89% of the commercial fish catch is produced in the lower reaches of the large northern rivers and lakes in the Arctic and subarctic zones of Yakutia. The main part of this catch is whitefish species, which are valued for their fat content, protein content, culinary, and taste qualities. Fish is a valuable food product for the population of Yakutia. This article presents the results of the study on the nutritional value and the content of heavy metals in the Arctic cisco meat. The high content of fat and protein in the studied samples shows that the Arctic cisco meat belongs to high-protein and high-calorie products and has a high biological value. It was found that on average, the level of toxic metals in the Arctic cisco meat does not exceed the norms accepted in Russia for fish products. The data obtained suggest that the content of heavy metals in fish is due to the peculiarities of living conditions and environmental pollution. Over the past decades, the volume of fish production in Yakutia has been declining due to the socioeconomic and climatic factors. Due to the anthropogenic pollution of water in rivers and lakes by oil products and effluents and waste from various sectors of the economy, especially the mining industry, there is a reduction in the fish resources and there is a need to monitor the environmental condition of the fishing reservoirs and the fish food quality.

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The article is dedicated to clarification of dependence of the Macaulay duration on the period until maturity by accounting the behavior of this indicator between coupon payments. The problem of dependence of bond duration on the period until maturity accounting the behavior of duration between coupon payments has not been considered before. It has been observed that the Macaulay duration varies linearly during a coupon period and in the end of the period the duration jumps in direct proportion to the period until maturity. The maximum jump for discount obligations is in the region of long periods until maturity. We have received evidence of how the jump depends on the period until maturity. The article contains calculations of how the duration jump depends on the period until maturity. These calculations confirm the proven statements. The obtained results may be useful for long-term investment problems.

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The anthropogenic pollution of the environment leads to the discharge of various pollutants into water ecosystems, which further accumulate in fish and other hydrobionts. Fish is a valuable traditional food source for humans, and the quality assessment for fish products is therefore a relevant problem. This article deals with researching the content of pollutants in game fish, in particular in the Siberian whitefish. The goal of this work is to identify the content of heavy metals and cesium 137 in the muscle tissue and organs of the fish (whitefish) caught in the lower reaches of the Lena River. Research methods: The sampled materials were tested for heavy metals using the atomic absorption method. The content of Cs 137 was established using the spectrometric method. Results: the average concentration values for heavy metals (mg/kg) (Pb, Cd, Hg) in the muscle tissue and organs of the whitefish do not exceed the limits. The average content of lead in muscular tissue is 0.0135±0.0025 mg/kg, cadmium - 0.0076±0.0014 mg/kg, and mercury 0.0011±0.0000 ug. Arsenic was not found in the muscle tissue and organs of the fish. The highest relative content of heavy metals was observed in the livers of the whitefish. The content of cesium 137 is insignificant and below the allowed level of radionuclide activity. Conclusion: The analysis of the research results shows that the contents of heavy metals and cesium 137 in the fish caught in the lower reaches of the Lena do not exceed the standard levels. The on-going pollution of lakes and rivers within the Lena watershed calls for regular monitoring of heavy metal and radionuclide content and accumulation in game fish.