Міграція селену у біогеохімічному ланцюзі: ґрунт– вода– рослина–продукція птахівництва–людина

Abstract

<p>Selenium is an essential micronutrient required for normal functioning of living organisms. It is distributed in inorganic and organic forms in marine and freshwater systems, in soils, biomass, and atmosphere. Its distribution patterns in terrestrial ecosystems have great diversity. There are biogeochemical provinces with selenium deficiency and toxic concentrations of this trace element. Variability of biochemical characteristics of soil and water in different regions of the world makes significant differences in the content of selenium in plants. The total content of selenium in plants depends on several factors: soil type, pH, redox potential reserves of selenium in soils, selenium compounds form (available or unavailable), precipitation, temperature and growth stage of the plant.</p><p>There is a correlation between the content of selenium in the soil and feed on plants, on the one hand, and animals and birds – on the other. Cereal crops, animals and birds, grown in soils of different types of ecosystems are included in human food chain, therefore food is a major source of selenium for human organism. Selenium status of the population varies, from 10 g<sup>-3</sup>/day in selenium deficient regions to 1400 g-<sup>3</sup>/day in regions with selenium toxicity.</p><p>Large number of countries are characterized by moderate and low levels of selenium intake from foods of plant-grower and stock-raising. Inadequate flow of it in the body (depending on the degree of deficiency) could lead to physiological changes within the normal regulation or significant metabolic disorders or cause the specific diseases, since selenium deficiency is associated with more than 75 different diseases and pain symptoms. The only way of selenium contamination increase in human organism is the selen inclusion in the diet enriched with such micronutrient, like poultry meat.</p><p>The selenium-enriched dietary meat product can be considered as biocorrection food and iIts consumption will contribute to the prevention of hiposelenoz. Nevertheles, there is a narrow range between the recommended rates (50–120 g<sup>-3</sup>/day) and the maximum permissible level of selenium consumption (400 g<sup>-3</sup>/day) while at high concentrations it can cause toxic effects in human body. Further comprehensive environmental and toxicological studies of migration patterns and levels of selenium in the environment should be done to minimize adverse effects to human health associated with dangerous concentrations of selenium.</p>