The problem of a high latitudes stress occurence in the extreme climatic and geophysical factors influence is evidenced by numerous studies . Deryapa et al, analyzing the results of the corticosteroid hormones content in human blood studies in Antarctic, made a conclusion about the moderate stress manifestations as an adaptation process at high latitudes extreme conditions. Korolenko considers mental status changes in the North as a form of an organism adaptation in acute or chronic stress conditions.
Our studies showed that environmental stress severity can be determined by a mortality increase among working-age people in a particular territory compared to the similar indicators in comfortable climate-geographical conditions. At average, 16–59 years old mortality rate in these regions were 6.1 cases per 1000 of the corresponded age population. Similar mortality rates have found in about 17–18% of all Russian territories. Comparison of indicators in the uncomfortable and comfortable regions of the North indicates a significant mortality growth in these areas for the analyzed age group, as well as the environmental stress high severity degree.
Confirmation of the environmental stress presence in the northern inhabitants on our data is the high psycho-emotional stress level in 63.7% of the examined healthy people permanently live in the area. At the same time, in 32.5% of examined, the psychoemotional stress level exceeded normal volume by 1.5 times, and in 31.2%, it was 4-5 times higher than the norm. A similar picture of the northern environmental stress presence is observed according to the blood cortisol concentrations. As shown by a sample survey of the northern residents without any disadaptive or pathological manifestations (about 30% of surveyed), the normal cortisol concentration is at the range 265-314 nmol/l. A large proportion of the surveyed healthy subjects differed with a significantly higher hormone concentration. Along with the mortality rates increase for working-age people in the North, the presence of environmentally determined stress is expressed in the psycho-emotional and endocrine manifestations in over 60% of healthy people.
Cosmic, geophysical, and meteorological changes are attributed to the northern stressors .The anthropogenic and technogenic factors; air, water and soil pollution turned out to be an important bio-negative element of the circumpolar environment. Changes of social and technological factors in this direction may increase the negative effect of extreme climatic and geophysical factors, enhancing the northern stress.
Multiple studies in Arctic and Antarctic allow to attribute the central nervous and endocrine systems reactions, metabolic changes and an oxidative stress development to the most typical manifestations of climate-geographic stress [2, 3, 8]. It has been proven that the stress resulting from the environmental factors negative external influence at high latitudes ensures the launch of the most important homeostatic adaptation mechanisms mobilization and is a completely relevant reaction designed for the necessary protective processes activation.
Long-term stress causes depletion of an organism reserve capacity, which subsequently leads to the development of a disadaptive disorders cascade, and later the pathological conditions occurrence. These observations are consistent with the theoretical conclusion that an exhaustion stage, which may occur during stress, already characterizes an adaptive stress response to pathology transition. The understanding of the northern stress as a basis of environmentally determined adaptive mechanisms activation, and an organism’s reserve capacity exhaustion, as the essence of general pathological and disadaptive reactions occurs in the North, is significantly improved.
Currently, northern stress, with its general pathological consequences, is perceived as an organism-generalized syndrome in the North, in contrast to Hans Selye’s stress syndrome, which is a global biological phenomenon. The relationship of human disadaptive processes at high latitudes with the geomagnetic environment features, insolation and temperature modes, tidal and non-tidal gravity forces, nutrition, social climate – allowed researchers to call this phenomenon a polar strain syndrome .