Vol 98, No 3 (2019)

Introduction. The criteria used for the sanitary-bacteriological assessment of the quality of tap water should ensure its epidemic safety, which is important when choosing priority indicator microorganisms, quantitative determination of which will allow characterizing the risk of intestinal infections associated with water use conditions with sufficient reliability.

Material and methods. Analyzed water studies for 10 years for the presence of sanitary-indicative bacteria in the water of surface water bodies in accordance with the guidelines MUK 4.2.1884. To isolate and quantify Salmonella, there were used the conventional magnesium medium and the developed nutrient medium, ready for use. The obtained data were processed using the statistical software package Statistic for Windows.

Results. It has been established that E.coli can be considered as an additional indicator in order to assess recent fecal contamination. The absence of E.coli in drinking water does not guarantee the absence of other members of the family Enterobacteriaceae. Pathogenic and potentially pathogenic bacteria exhibited the greatest viability. E. coli turned out to be less stable, i.e. microorganisms, on an indication of which the system of sanitary and epidemic safety of the water use was built. In the experiments, lactose-positive coliform bacteria were established to be less resistant to the action of disinfecting agents than salmonella and potentially pathogenic bacteria, which should not be inherent to the indicator microorganism.

Conclusion. Research results indicate that the absence of normalized lactose-positive fecal indicators fails to guarantee the absence of infectious agents since lactose-negative enterobacteria are unaccounted for — pathogenic and potentially pathogenic species causing intestinal infections. Therefore, in the sanitary-bacteriological control of tap water, it is more expedient to focus on the indicator glucose coliform bacteria (GKB).

There was studied lipid composition of blood plasma and erythrocyte membranes, physiological characteristics of erythrocytes in divers, exposed to extreme factors of the hyperbaric environment in the process of the occupational activity. There was observed a group of 10 male divers from 25 to 30 years of age, whose work is associated with the systematic implementation of submarine dives at medium and large depths (20-60 m) using compressed air for breathing. The influence of hyperbaric stress was shown to be accompanied by the change in a ratio of fatty acids in the total lipids of blood plasma and erythrocyte membranes. In total lipids of blood plasma and erythrocyte membranes the number of all kinds of saturated fatty acids (myristic acid, palmitic acid, stearic acid), the monounsaturated fatty acids (palmitoleic acid) was increased and an amount of polyunsaturated fatty acids of n-6 family (arachidonic acid) and n-3 (eicosapentaenoic acid) was reduced, which caused a change in physicochemical properties of erythrocytes, permeability, and lability. The increase in the amount of cholesterol in the erythrocyte membranes correlates with its elevation in blood plasma. There was an increase in the volume of erythrocytes by 5% and diameter by 13%, due to the inclusion of cholesterol in the membrane. It was recorded a shift in the threshold of hemolysis start at 0.50 ± 0.02% NaCl and its completion at 0.40 ± 0.01% NaCI. Preventive administration of the Kalifen food supplement for two months before the dive would help to remove metabolic disorders caused by the hyperbaric factors.

Introduction. The article discusses the results of a general analysis of information on the radiation-hygienic passports of Moscow in the period from 2013 to 2016, providing objective and accessible information about the characteristics of all sources of ionizing radiation (man-made, medical, natural) and the resulting radiation doses for the population Moscow.

Material and methods. A qualitative and quantitative assessment of doses for the population from natural sources, medical exposure of patients during X-ray examinations was carried out, the objects of Moscow using sources were studied.

Results. The number of sources in Moscow has been established to be indicated inaccurately, as a result of which unaccounted sources are identified during control and supervisory measures. The leading role in the structure of collective doses of radiation to the population of Moscow according to the data of 2016 was shown to come from natural sources and medical research as much as 81.5 and 18.3%, respectively. A continuous increase in the dose from computed tomography and its significant contribution to the collective dose from medical exposure of Moscow residents was noted. In 2016, its contribution amounted to 59.9%.

Discussion. To determine the qualitative and quantitative assessment of the doses to the population of Moscow from all sources, the radiation hygienic passports of the city of Moscow were studied from 2013 to 2016.

Conclusions. On the basis of the study conducted to assess the doses of radiation to the population of Moscow, an underestimation of the effective doses of patients during medical research was established. There is a continuous increase in the dose from computed tomography, its significant contribution to the collective dose from medical exposure of the population of Moscow. In order to update the radiation hygienic passport of Moscow, it is necessary to achieve the presentation of complete information by objects using sources, as well as the relevance of legal acts, taking measures to prevent an unreasonable increase in doses of medical exposure to residents of Moscow while actively introducing highly informative diagnostic methods in medicine.

introduction. The leading place in the Russian Federation and in the world is occupied by cardiovascular diseases (ischemic heart disease, hypertension, and peripheral vascular diseases), which are the main cause of disability and death worldwide.

The aim of the research was to study the prevalence of cardiovascular pathology in workers of the aluminum industry.

Material and methods. We examined 66 workers of the aluminum facility without occupational pathology and 135 employees who never worked in adverse working conditions (the control group). All the examined subjects were men; the average age accounted for 52.08±0.4 years. 

Results. The study showed the workers of the aluminum facility to develop such diseases of the cardiovascular system as arterial hypertension, atherosclerosis with lesions of peripheral and extracranial arteries, as well as multifocal atherosclerosis more often than in those who do not work in adverse working conditions (the control group). 

Conclusion. The unfavorable occupational factors of aluminum industry are an additional risk factor for the development of cardiovascular pathology.

introduction. The paper presents hygienic approaches to the development of methods for the hygienic assessment of pedagogical technologies in terms of the safety for the health of pupils and effectiveness in terms of improving the quality of education. The aim of the study was a hygienic assessment of innovative technologies of enrichment in primary school.

Material and methods. The pupils of primary classes of the second year of the education were examined in two educational organizations of the city of Irkutsk. One group of children was trained according to enrichment training technology (60 children), the second – to a typical general education program (65 children). A total of 125 children were examined during the second year of study. The hygienic factors of the organization of the educational process were studied using the methodology for assessing the intensity of the educational work, the conditions for organizing the educational process, as well as texts of textbooks for readability (the Flash index) and the understanding of texts (Fog index). The obtained data are compared with the main criteria of the state of neuropsychic development of children: intellectual development (according to the method of Raven’s test with the definition of abilities to isolate relationships, analogies, rearrangement, decomposition and progressive change in the matrix of figures), mental performance (according to the method by V.Ya. Anfimov), short-term memory (Ray test).

Results. With the innovative technology of teaching, the intensity of the training work was established to be approaching the third degree of intensity of the training work by the criterion of intellectual loads: 2.9 ± 0.16 points with enrichment training technology and 2.2 ± 0.09 points in the conditions of training under the standard program p < 0.05). Indices of the sensory and emotional intensity of the educational work with the technology of enriched learning were statistically higher also (p < 0.05). The increase in the intensity of the educational work was accompanied by a decrease in intellectual development, short-term memory and mental performance (p < 0.05). Conclusions were made about the need for a comprehensive hygienic assessment of the safety for health and the effectiveness of innovative pedagogical technologies based on the developed methodology.

Conclusion. It is proposed to allow using pedagogical technology in educational organizations only after hygienic examination of its approbation in the educational process.

Introduction. An investigation aimed at studying the modern specific features of the physical development of children of school age of Yekaterinburg city was performed. 

Material and Methods. Somatic (body length, body weight, chest circumference) and physiometric (vital lung capacity, hand strength) physical development indices of 1378 school students of the city of Yekaterinburg aged from 8 to 16 years were surveyed and studied using the anthropomorphic measurement method (cross-sectional studies). The obtained results were compared with the equivalent physical development results collected from the children within the period between 1894 and 2000, as well as physical development data of school students residing in the large cities of the Russian Federation; Student’s t-test, regression analysis were used.

Results. A decline in somatometric indices of the physical development (body length, weight, chest circumference) in all age and gender groups of school students was noted within the period between 1894 and 2017, but the decreased average values of the physiometric parameters, i.e. vital lung capacity, hand strength, were noted from 1985. The average body length and average body weight of school students of the city of Yekaterinburg are not significantly different or higher as compared to the peers residing in the large cities of the Russian Federation. In contrast to the regional physical development standards (as of 2000), each third school student has high or higher than average physical development indices: body length by 26.4%, body weight – 36%, chest circumference – 29.8%; a high incidence of low physiometric parameters was noted: low and lower than average indices of the vital lung capacity are characteristic to 35.1% of school students, hand strength – to 20.4% (right) and 22.9% (left) school students.

Conclusion. The obtained results are indicative of the epoch-making changes in the physical development of children of the school age, as well as of certain regional distinguishing features, which may be associated with changes in the social and economic, environmental situation, and life style peculiarities of the modern school students.

The data presented in the article show the results of the research of educational conditions and adaptive capabilities of students of secondary vocational education training as operators of woodworking machines at the beginning and at the end of the apprenticeship. The value of microclimate indices was revealed to go beyond the allowable level (the indices of temperature were from 25.8C° to 26.3C° while the airspeed was from 0.00 to 0.02 m/sec and the relative humidity reached 34%. The artificial illumination of the working surface on several machines doesn’t match the hygienic requirements (500 lx) and fluctuates from 205 lx to 305 lx. The volume level in the workshop during the work of woodworking machines varies from 79 to 86 db. And wherein, the time regulation and the using of means of collective and individual protection are not implemented right along. In accordance with the Jan Strelau classification genetically determined types of higher nervous activity define organism adaptabilities to the changes of environmental conditions. Students were divided into less adopted (melancholic, choleric, sanguine choleric, melancholic choleric) and more adopted (phlegmatic, sanguine, phlegmatic sanguine, phlegmatic melancholic) groups. Student’s adaptive capabilities were evaluated by indices of cardio-respiratory synchronism test. At the end of the apprenticeship student’s regulatory adaptive capabilities were revealed to decrease. Thereby the regulatory adaptive status index of students training as operators of woodworking machines was decreased by 65.3% in the less adopted group, and by 57.1% in the more adopted group. During the apprenticeship, the complex on unfavorable factors (including professional, caused by the specificity of the chosen occupation) affects the student organism. The index of unfavorable factors influence, depending on vocational training conditions is the integrative estimation of the functional state of the student organism, determining by cardio-respiratory synchronism test parameters.

The study of actual nutrition and nutritional status was conducted in 180 residents of the settlements of Tazovsky and Gyda of the Yamal-Nenets Autonomous District. In comparison with the out-of-town population, Arctic indigenous people reliably consume bakery products, meat products (due to venison), fish and fish products, and less - dairy products, vegetables and mushrooms, fruits, berries, dried fruit, vegetable, fruit and fruit juices. When analyzing the chemical composition of the diet, in comparison with the indices of the newborn population, the caloric content of the ration was significantly higher because of its higher protein content (18% of calories). The fat content in the diet of the indigenous population was almost close to the recommended values (30% by caloric content), while in the alien population it exceeded them (33%). The indigenous population, in comparison with the out-of-home population, had a lower content of total and animal fat in the diet, mono- and disaccharides against a background of lower BMI (27.2 kg / m² and 28.8 kg / m², respectively) and fat mass. Body factors also were affected by genetic factors. The indigenous population consumed less Vitamin C (2 times) compared to the alien, which was due to the significantly lower content of vegetables, fruits, berries and fruit juices in their diet, and Ca at an unfavorable ratio of Ca: P (1: 2.5) On the background of insufficient intake of dairy products, and more - sodium due to canned (smoked, dried and salted) fish.

Biological rhythms are genetically fixed as a universal form of adaptation to cyclically changing environmental factors. Many organs including the liver and body systems function in an oscillatory mode. Its central role in the process of detoxification may determine the variability of toxic effects in the metabolism of xenobiotics. The including of chronobiological patterns in the procedures of toxicological and hygienic studies will allow more accurate assessing of the properties of tested substances. The aim of the study was to identify variations in the seasonal chrono-reactivity of warm-blooded animals to the hepatotoxic effects of carbon tetrachloride. In studies there were used Wistar rats, divided into experimental (CCl₄-induced toxic hepatitis) and control groups in the winter, spring, summer, and autumn. Standard laboratory diagnostic methods studied key indices characterizing the functional activity of the liver and the antioxidant status of the organism (direct and total bilirubin, cholesterol, alkaline phosphatase, ALAT, ASAT, hydroperoxide, malonic dialdehyde, catalase in the liver tissues). According to the results of the conducted research, seasonal biorhythms have a modulating effect on the organism of warm-blooded animals, and the amplitude of the detected fluctuations was observed to be wider in terms of modeled pathology. The calculation of the variation values of numerical indices shows fluctuations to take place in the range of 10-60% in control group, and within the range of 60-300% in the pathology. The most labile index was catalase. Since the mechanism of carbon tetrachloride toxicity is mediated through the initiation of lipid peroxidation, this may explain the observed phenomena of seasonal chronoreactivity. Thus, taking into account the modulating role of biorhythms in protocols for toxicity testing can optimize the currently used procedures of human health risk assessment.

Introduction. Single-walled carbon nanotubes (SWCNTs) can affect the human body as a result of their use in packaging materials, growth stimulators of agricultural plants and promising agrochemicals. 

The aim of the study was to investigate the effect of SWCNT on integral and biochemical indices on the model of oral administration to rats in a subacute experiment with duration of 92 days.

Material and methods. SWCNT were dispersed by ultrasound in water with 1% by weight of the non-ionic surfactant Tween 20. According to the data of dynamic light scattering, electron microscopy, and Raman light scattering the sample containing both free and partially aggregated SWCNTs. The experiment was carried out on 5 groups of growing male Wistar rats. The SWCNT dispersion was added to the drinking water at doses (control); of 0.01; 0.1; 1.0 and 10 mg/kg body weight in groups from the 1^st to the 5^th group. We studied the level of anxiety and cognitive function in the test of the “Conditional Reflex of Passive Avoidance” (CRPA); the mass of internal organs, the permeability of the small intestine wall for ovalbumin macromolecules, the biochemical parameters of blood serum, the activity of glutathione peroxidase, the content of non-protein thiols in the liver, urinary excretion of 8-hydroxy-2’-deoxyguanosine (8-oxo-G) and selenium.

Results. As a result of SWCNTs consumption there were found significant changes in the content of total protein, uric acid, triglycerides, cholesterol in the blood serum, the increased activity of aspartate aminotransferase, the relative mass of the liver, and decreased the permeability of the intestinal wall for macromolecules of the protein. There have been shifts in individual antioxidant protection indices, including increased 8-oxo-G excretion, decreased glutathione peroxidase activity, glutathione content in the liver, and selenium availability. Most of the above effects did not show a dose dependence of the nanomaterial and were more pronounced at minimal and medium doses of SWCNTs than at maximum doses. The effect of SWCNTs on the behavioral responses of animals was not revealed. 

Conclusion. Therefore, SWCNT show signs of toxic effects at a dose of 0.1 mg/kg body weight in a day or less.

Introduction. Persistent organic pollutants (POP) are extremely dangerous compounds contaminating the environment and exerting the negative impact on human health. Organochlorine pesticides, including hexachlorobenzene, are a specific group among POP. Our research goal is methodological support for the hexachlorobenzene content control in human biological environments.

Material and methods. We developed highly both sensitive and selective procedure for determining hexachlorobenzene in blood. Hexachlorobenzene determination in blood is based on the application of capillary gas chromatography with linear programming of a column temperature, electron capture detector (ECD), and extraction with an organic solvent at a sample preparation stage. When implementing the developed methodology, the following indices were evaluated: accuracy and error characteristics of the analysis results. The lower limit of hexachlorobenzene quantification (LOQ) in blood amounted to 0.000024 µg/cm³, with the range of detectable concentrations from 0.00015 to 0.005 (determination method error ≥ 20%), which allows to adequately diagnose chemical burden with a highly toxic persistent organic pollutant in blood.

Results. The results of quantitative chemical analysis of hexachlorobenzene contents in blood had the following quality indices: precision and correctness amounted to 15.621%; repeatability - 3.45%; reproducibility - 4.65%. In the process of testing the method, concentrations of hexachlorobenzene in the range of 0.0003 ± 0.0001 ÷ 0.0007 ± 0.0001 μg/cm³ were detected in the blood of the examined group.

Discussion. The high efficiency of gas chromatography determination of hexachlorobenzene in blood was achieved via selection of optimal conditions for chromatographic analysis: capillary column HP-1- 35m∙0.32mm∙0.25µm with linear programming of column temperature, carrier gas (nitrogen), electron capture detector (ECD). The developed method of the preparing a blood sample for analysis, including liquid extraction with toluene, protein denaturation by centrifuging the biological medium at 7000 rpm for 15 min at pH of 6-7 in combination with gas chromatographic analysis and an electron capture detector (ECD) made it possible to complete extraction of hexachlorobenzene from blood in an amount of 99.7%.