The article contains data on the prevalence of the health behavioral risk factors of Moscow schoolchildren of 7-8 and 10-11 grades. The unfavorable factors in relation to health are revealed: high level of school load, unhealthy food, lack of physical activity, consumption of psychoactive substances, aggressive behavior. There are presented their gender and age differences. Practical preventive measures to reduce the risk of health disorders are proposed.

The article presents an analysis of the data of longitudinal health study of the same Moscow schoolchildren, observed by medical specialists from the Institute of Hygiene and Health Care of Children and Adolescents from the 1st to the 11th grade. The morbidity dynamics of functional dyspepsia, biliary dyskinesia, functional intestinal disorders, chronic gastroduodenitis, peptic ulcer disease, underweight, overweight, obesity, juvenile struma was considered. In addition to reviewing the data on the prevalence of these health disorders, assessment of the course of pathological processes for each nosology was carried out over a period of 11 years. It was revealed that the studied health disorders are characterized by an increase in the prevalence and/or adverse course of pathological processes in school ontogenesis. The high prevalence of these health disorders and the worsening of clinical symptoms in 43-65 % of students indicate the negative role of the excessive training loads, psycho-emotional overstrain and pre-examination stress in the formation of pathological conditions in grades 9-11.

This study of the values of functional indices of cardiovascular, respiratory, muscular-ligament systems and vestibular analyzer in 146 junior schoolchildren (68 boys and 78 girls) 8-9 years was conducted for the purpose of a complex comparative characteristic of the functional status of the organism of children of different gender at the initial stage of implementation of a differentiated approach to the organization of physical education. The analysis of the results revealed differences between boys and girls in the inspiratory breath delay (23.3 ± 1.0 s and 19.8 ± 0.7s, respectively; p < 0.05), the vital capacity of lungs (1 532 ± 45 ml and 1 406 ± 34 ml, respectively; p < 0.05), the level of static balancing (4.3 ± 0.3 s, 6.6 ± 0.5 s, respectively; p < 0.05) and stato-kinetic stability (5.00 ± 0.20 rev and 5.64 ± 0.20 rev, respectively; p < 0.05), left hand muscle strength (8.4 ± 0.2 kg and 7.7 ± 0.2 kg, respectively; p < 0.05). Functional muscular testing showed that the muscles and ligaments of the neck, shoulder girdle, pectoral muscles and muscles of the trunk from boys are more often in the enslaved state than in girls. The tests for the condition's evaluation of the muscles and ligaments of the neck, shoulder girdle, pectoral muscles was not performed by 27.9 % of boys and 7.7 % of girls (p < 0.05; test 2); 48.5 % of boys and 15.4 % of girls (p < 0.05; test 1); muscles and ligaments of the trunk - 10.3 % of boys and 1.3 % of girls, p < 0.05; muscles and ligaments of the pelvis and lower limbs - 1.5 % of boys and 3.8 % of girls, p > 0.05. The results demonstrate the features of functional status of the organism of children of primary school age of different gender and can be used for hygienic substantiation of the differential approach to the organization of their physical education.

The article presents the results of the study of the impact of living standards on the health of children and adolescents according to the Federal Information Fund of social and hygienic monitoring. The dynamics of morbidity of children and adolescents with socially significant and the main classes of diseases is shown. The indicators of the Federal information Fund for social and hygienic monitoring show an overall picture of the primary incidence of children aged 0 to 14 years, and adolescents from 15 to 17 years, including socially significant and the main classes of diseases without taking into account the principles of age periodization and do not allow to identify the characteristics of the incidence of children and adolescents of different age groups. The higher the subsistence level, the higher the incidence of childhood obesity; the lower the percentage of people with incomes below the subsistence level, the higher the incidence of obesity among children and adolescents. The incidence of obesity in adolescents (as a less sensitive group) did not have a significant impact on the subsistence minimum. The socio-economic situation ofthe regions affects the behavior and morbidity of children and adolescents: the higher the subsistence level, the higher the incidence of obesity in children and the proportion of children and adolescents with reduced visual acuity.

In modern conditions, there is an increase in the prevalence of mental disorders among all age groups and high rates of adolescent suicides. The purpose of the study is to assess the sanitary-epidemiological and psychological well-being of adolescents studying in various educational institutions. The object of the study was 100 girls and 100 boys aged 15-18 years, studying in general education schools and colleges. The study used hygienic, sociological, clinical, follow-up and statistical methods. The assessment of the conditions and organization of training in the schools surveyed allowed them to be classified as optimally acceptable, and in colleges - to potentially dangerous, and to predict in the latter the formation of morphofunctional deviations in adolescents. Various forms of mental disorders were revealed in 67.5 % of the surveyed patients. A significant part (36 %) of them were made up of painful conditions, 16 % of them - neurotic reactions, 20 % - pathocharacter reactions. Actually, neuroses were revealed in 20 % of surveyed patients. There was found a significant prevalence of mental disorders in adolescents in colleges - 82 %, compared to schools - 53 % due to pathocharacter reactions. Pathocharacterological and accented personal characteristics are the most important predictors of mental disorders. From them are formed risk groups, which should be in the sphere of attention of medical and pedagogical workers of educational organizations. The features of the formation of mental disorders in adolescents require primary and secondary psychoprophylaxis in these groups.

The article is devoted to the study of mental working capacity and emotional state of schoolchildren of 59 grades of different age and gender groups in the lessons with and without using a PC. There were observed 277 students of grades 5-9 (113 boys and 164 girls). Dynamic changes in the indices of mental working capacity and emotional state of children of different gender were analyzed at 94 lessons. It is shown that the use of computers in the educational process is a significant factor in the formation of fatigue in pupils of both gender, but the nature and level of reaction to it are not the same for boys and girls. The use of PCs in the classroom predetermines a variety of changes in the studied indicators, the orientation of which depends on the gender, age and time of its use in educational activities. The different duration of use of the PC affects, first of all, the quality of the proof-reading work - its accuracy. From the beginning to the end of the training in the main school, against the background of the growing intensification of training, the resistance to the training loads associated with the use of the PC in the lessons of girls is increasing, and in boys is decreasing. This indicates the need to take into account the various psychophysiological reactions of children of different gender, as well as the peculiarities of their perception of educational information in the development of methodological support for the learning process associated with the use of a personal computer.

The hygienic assessment of pedagogical technology of studying of younger schoolchildren in the conditions of active sensory-developing environment was carried out. This technology was developed to reduce the tedious impact of a large educational load on the health of schoolchildren. In the far North its negative impact is increased by especially severe climate, lack of exercise and «sensory impoverishment». Learning in an active sensory-developing environment contributes to a more favorable course of adaptation to the educational requirements, reduce the fatigue of lessons and the prevalence of adverse changes in the cardiovascular system, neuropsychological status of children. The increase in the volume of motor activity of children in the learning process, the use of ophthalmic devices, furniture for standing-sitting classes, provided for by the new pedagogical technology, contributed to a more marked than in the control group reduction of visual fatigue and acute morbidity of schoolchildren. Health-saving effect of learning technology in a sensory-developing environment contributed to the improvement of emotional comfort and educational motivation of younger schoolchildren and reduced destructive anxiety.

The article presents the results of hygienic assessment of the educational system «UniK», which is used in primary school. It was established that despite the more intensive organization of educational activities and fast-paced learning of program material using specially selected tasks, multimedia method of presenting information, the implementation of activities aimed at preventing fatigue, etc., its implementation is not accompanied by primary schoolchildren more marked fatigue than their traditionally trained peers, indicators of physical development and functionality do not deteriorate.

The social and hygienic features of life and health of adolescents living in four regions of the Russian Federation (Moscow, St. Petersburg, Omsk and Pskov regions) have been studied. The regional features of life on the peculiarities of the family, the prevalence of unhealthy lifestyles, and satisfaction with the organization of training and professional orientation of students, employment, as well as indicators of health and quality of life associated with health were studied. The best indicators of health and quality of life associated with health were observed in adolescents of Omsk region, with the best characteristics of living conditions. The importance of the development of comprehensive regional prevention programs to reduce the risks to the health of adolescents is substantiated.

In a one-stage study of 135 Moscow schoolchildren of 1st -3rd grade (2017-2018) the meanings of energy flux density (EFD) of individual mobile phones (MP) was measured, and modes of MP use and health indicators were determined by questionnaires. The EFD maximal values exceeded the norm for adults (100 μW/cm2) in 43.5 % of children. In most children, the total daily duration of calls (TDC) reached 6 minutes, their number (NC) 1-4 and the duration of each (DC) 1-4 minutes. The positive correlations (p < 0.04) were found between the time mode of MP use and health violations. They were more numerous in the group of children with normal anamnesis (80 people), in which the influence of MP was not masked by an abnormalities of early development. These correlations were found for the incidence of headache (NC r = 0.24, TDC r = 0.26) and of anxiety (DC r = 0.22). The incidence of giddiness positively correlated with the PFD (r = 0.24). Negative correlations (p < 0.04) were found of the frequency of inattention, forgetfulness, sleep disorders with the years of MP use (r from -0.24 to -0.36), and also positive correlations were found for the frequency of headache and of anxiety with the age of children (r= 0.27). The results attest to the predominantly negative impact of MP radiation on the children central nervous system and require the regulation of the MP use in childhood.

The experience of schools in the organization of health saving of pupils in the Republics of Azerbaijan, Armenia, Belarus, Kyrgyzstan and Moldova was studied. According to the materials of the self-audit and expedition survey of schools, there was evaluated their involvement in the network of health schools, focus on the effective education of students in the field of health, the adequacy of conditions and the degree of comfort of the educational process for the formation of health. It is established that the majority of schools are at the initial stages of implementation of programs on preservation and strengthening of health of the trained. In the expert evaluation of the indicators of complex questionnaire of schoolchildren characterizing their psycho-emotional state, prevalence of behavioral risk factors and complaints of health disorders, as well as awareness of health issues and health promotion of a healthy lifestyle culture, there were no marked differences in students in schools with different levels of health - saving activities. Based on the results of scientific research, unified practical recommendations (road map) have been developed for the National coordinators of the network of health schools, education and health authorities of the Republics.

This paper deals with study of the seasonal vitamin provision for 188 organized children attending preschool educational institutions with standard main meal C-fortification. The study showed that 7585 % of children have year-round vitamin deficiency, 40 % of whom have it in the nature of polyhypovitaminosis. The study has shown that even in the autumn-winter period the basic vitamin provision for children does not exceed the lower bound of the physiological norm, and during the spring months about 70 per cent of children suffer from subclinical vitamin C deficiency and 15 % suffer from vitamin A deficiency. While every third child has a vitamin B₆ deficiency, and every 10 has vitamin D deficiency in September and October, in April-May the number of children with insufficient provision of these vitamins is 1.8-6.3 times more. А dynamic study of the vitamin provision for organized children found that half of them suffer from year-round vitamin B₁₂ deficiency. Risk assessment of somatic health disorders in children with polyhipovitaminosis revealed that the low vitamin level in the blood leads to increase in the risk of children physical developmental abnormalities, dysfunction of vascular tone and vegetal responsiveness, not to mention the fact that children's morbidity of chronic somatic diseases is 1.3-2.2 times more. Low vitamin provision increases 1.6-3.2 times the risk of physical and biological development during childhood; leads to the development of functional disorders of the respiratory, cardiovascular and autonomic nervous system 2.1-3.3 times more. For children suffering from polyhipovitaminosis the risk of developing chronic diseases of the gastrointestinal tract and nervous system, allergic respiratory and skin diseases, as well as musculoskeletal disorders is 1.3-4.1 times higher.