Vol 26, No 9 (2019)

The article presents an overview and summarizes the accumulated international and national experience, highlighting the formation and main stages of the development of the theoretical foundations and practical significance of the use of biomarkers in medico-ecological studies and evaluations in terms of influence of harmful chemical factors on the human organism. It is shown that in order to increase the effectiveness of evidentiary causal relationships of developing negative effects and modifying the mechanism of their development with the adverse effects of environmental factors, the need to expand scientific research in the field of biomarkers, their selection criteria, and justification of reference levels is becoming more urgent. In accordance with the opinion of experts from the Ad Hoc Collaborating Organizations on Biomarkers (UNEP, ILO and WHO), biomarkers of three classes were identified - exposure biomarkers, reflecting exposure, sensitivity, characterizing the degree of organism susceptibility to exposure and markers of negative effects, indicating the development of the body's response to the effects of risk factors. Based on the currently existing international approaches and taking into account national competencies, a characteristic was given and the practical significance of each class of biological markers was shown when solving problems of substantiating cause-effect relationships in the system «environment - human health» and making adequate management decisions.

The problem of homeostasis and especially homeostatic behavior of different parameters of the human body functional systems in the Russian North (human's cardiovascular system (CVS) is considered in the work) was reviewed from new perspective (new theory of chaos and self-organization). After proving of N. A. Bernstein's hypothesis about "repetition without repetition" in biomechanics as a statistical instability of obtained samples (in one subject with universal homeostasis) a problem explaining mechanisms of such instability appeared. One of the mechanisms of such stochastic chaos for RR intervals and over parameters of cardiovascular system may be connected with chaotic dynamics of parameters of the human environment. The purpose of the study is to assess the influence of external chaos (parameters of the human environment) on internal regulatory functions. Using the methods of paired comparison of samples of meteorological parameters and calculation of quasi-attractors' parameters, we obtained information on the state of meteorological parameters of the human environment, which demonstrate stochastic instability in succession of samples obtained (identical months and the same seasons of the year). The results of the study showed that the average values of the areas of quasi-attractors of two phase coordinates (T, P) differ very significantly. It is suggested that such chaotic dynamics can induce chaos of the CVS parameters. The paper proves homeostasis in the behavior of meteorological parameters, which can significantly affect the systems of regulation of the main functions of the human body. The statistical instability of the parameters of the human environment is shown, which is very similar to the dynamics of tremor and teping in the Eskov-Zinchenko effect. Conclusions. The statistical instability of meteorological parameters is similar to the homeostasis of living systems. At the same time, the mechanisms of regulation of the CVS and meteorological parameters of the human environment are, of course, different. A common feature is the special chaos of the xi parameters, which is manifested in the statistical instability in a row of the resulting samples. Such a statistical instability is called the Eskov - Zinchenko effect, and has no analogue in such systems.

The aim of the study was to reveal the changes occurred in the cardiovascular system, ventilation, and heart rate in response to a rebreathing test in young male residents having different periods of adaptation to the conditions of the northeast of Russia. Methods: 222 young men took part in the study: 31 - representatives of the 0th generation, 73 - belonged to the 1st generation, 86 - representatives of the 2nd generation and 32 - indigenous people of Magadan Region. The basic parameters of cardiovascular system, heart rate variability and ventilation at rest and at the peak of the rebreathing test were studied. Results: The studies have shown that the process of urgent adaptation in response to hypoxic-hypercapnic effect occurs through alternation of the cardiovascular system as well as changes in heart rate and ventilation indicators. These changes have a number of differences depending on the period of residence in the northeast of Russia. Conclusions: It is found that the main characteristics of the cardiovascular system, arterial blood saturation and to greater extent ventilation when analyzing background-test difference, can serve as indicators of the adaptation degree to the conditions of the northeast of Russia as well as physiological criteria of ethnicity. However the most specific, reflecting the differences in the reconstructions of the studied systems in response to rebreathing in the subjects of the four groups are ACO2, AO2 as well as spectral characteristics of the heart rate, both at rest and at the peak of the test with recurrent respiration.

The aim of this study is to assess the contribution of food when providing Arkhangelsk city's residents, being of different age and sex, with selenium. Methods. 386 food samples were used for the analysis. Serum samples of 180 volunteers, including 90 men and 90 women of different age groups, were studied to observe the sex-and-age dynamics. Selenium content in the selected samples was detected by means of fluorimetric method in a liquid analyzer Fluorat "02-2M", according to the MG (methodological guidelines) 4.1.03395. Type of distribution for the samples was determined using Shapiro-Wilk test. To describe quantitative data with normal distribution, we used arithmetic mean, mean-square error of arithmetic mean, minimum and maximum values. Parameters with abnormal distribution were presented as a median. Validity of differences was analyzed using Fisher - Student and Mann-Whitney test: valid differences were considered having values < 0.05. Results. According to a research it is established that selenium content in food increases in the following sequence: fruit → vegetables → berries → mushrooms → eggs → grain products and pasta → fish products → meat products → milk and dairy products. The analysis of data showed that the average content of selenium in blood serum of women (Me = 60.85 mkg/l) is slightly lower, than in blood serum of men (67.09 mkg/l), (U = 908, p < 0.05). Conclusions. The data obtained indicate that the amount of selenium consumed by the residents of Arkhangelsk with food is on average within the lower limit of the norm recommended by World Health Organization. Despite this, slight selenium deficiency prevails among the surveyed residents. The analysis revealed that 4.4 % of women have a severe degree of selenium deficiency, 68.9 % of women and 61.1 % of men - a slight degree of insufficiency. Most residents of the city of Arkhangelsk are at risk of developing selenium deficiency.