Том 98, № 3 (2019)

Мұқаба

PROBLEM-SOLVING ARTICLES

Comparative assessment of the sanitary and epidemic importance of сoliform indicators of the drinking water quality

Rakhmanin Y., Ivanova L., Artyomova T., Gipp E., Zagaynova A., Maksimkina T., Krasnyak A., Zhuravlev P., Aleshnya V., Panasovets O.

Аннотация

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).

Hygiene and Sanitation. 2019;98(3):237-249
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ENVIRONMENTAL HYGIENE

Impact of hyperbaric stress on lipid composition of blood plasma and physiological-biochemical characteristics of erythrocytes in divers: prevention of violations by vegetable polyphenols

Kushnerova N., Rakhmanin Y., Momot T., Fomenko S., Sprygin V., Lesnikova L., Drugova E., Merzliakov V., Fedyanina L.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):250-255
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A differentiated approach to hygienic indices in evaluating the activity of radiation facilities

Korenkov I., Okhrimenko S., Samoilov A., Shestopalov N., Prokhorov N.

Аннотация

Policy management of institutes and business organizations’ activity, dealing with radiation sources, has more of a bulky and confusing complex of requirements at the present day. The requirements being very substantial, slow down economic growth of entire branches in the field of the beneficial use of radiation technologies, and, at the same time, do not provide the condition of radiation safety. Prime Minister Dmitriy Medvedev, without any coincidence, pointed out the problem during a plenary meeting as an overpressure of regulatory and supervisory bodies on the Russian private sector. According to him, the task can be solved with ‘a regulatory guillotine’. The upcoming article resembles the first attempt to analyze and sort reasons and factors, providing a glimpse of the current situation, search key elements that cause negative influence in the field taken. On the ground of analysis of regulatory documents, vast survey experience and estimation of radiation objects and technologies, authors suggest a new complex of requirements to provide radiation security, their breakdown of classes depending on danger level of radiation objects and operating with sources of ionizing radiation. The article presents the analysis of current regulatory documents on radiation hygiene field and radiation security, retrospective view on valid documents, the expertise of activity of regulatory and supervisory bodies as part of licensing of the activity with man-made sources of ionizing radiation.

Hygiene and Sanitation. 2019;98(3):256-260
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Results of radiation and hygienic passportization of the city of Moscow in the period from 2013 to 2016

Melnichenko P., Prokhorov N., Bolshakov A., Khodykina T., Zakharova A.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):261-267
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Hygienic analysis of potential risks of health harm in the implementation of airport complexes activity

Kleyn S., May I., Kiryanov D.

Аннотация

Introduction. The noise impact on human health continues to grow under the conditions of dense development of residential areas. Therefore it is necessary to forecast and identify priority activities and areas requiring special attention when conducting control and supervisory measures on the sanitary and epidemiological well-being of the population. 

Material and methods. The economic activity of airport complexes was assessed according to the potential risk to health. Also, spatial and structural distributions of potential risks were estimated. Health risk assessment in the zone of influence of airport complexes was carried out according to Guidelines 2.1.10.1920-04 and 2.1.00.0059-12. 

Results. The activity of airborne complexes, classified as “Air Transport Activity” category 1 by the potential risk of harm (R1 = 6.97 ∙ 10-3, the scale of the impact is more than 155 thousand people) and located in close proximity to residential development, is shown to representatively confirm the results of the assessment of the potential risk of harm to health. The activity of the analyzed economic entity forms non-normative quality of atmospheric air (up to 1.87 maximum one-time MPC., Up to 4.0 daily average (da) MACda, noise exposure exceedances - up to 90 dB at maximum and up to 66.6 dB at equivalent levels) carcinogenic risk (TCR up to 3.39E-04) and non-carcinogenic risk (up to 3.1 HQac, up to 43.5 HQcr, up to 5.13 HIac, up to 47.3 HIcr). The priority risk factors are benzene, formaldehyde, manganese and its compounds, copper oxide, hydrogen chloride, suspended solids, etc. The external average acoustic exposure forms high levels of risk at the age of 47 years of life (and older), moderate levels by the age of 15 years (and older). 

Conclusion. The current situation requires the development and implementation of a set of operational and planned measures of sanitary and hygienic, legal, technological, organizational, medical and preventive nature.

Hygiene and Sanitation. 2019;98(3):268-275
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OCCUPATIONAL HYGIENE

Prevalence of cardiovascular pathology in workers of the aluminum industry

Panev N., Korotenko O., Filimonov S., Semenova E., Panev R.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):276-279
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Health assessment of workers of meat processing plants

Pynzaru I.

Аннотация

Health assessment of workers of four meat processing plants in the Republic of Moldova in the 2011-2015 was carried out. The analysis of temporary disability showed the incidence the respiratory diseases (13.9±1.3 cases for 134.0±17.1 days per 100 workers) to prevail in the structure of disability), followed by the diseases of circulatory system (5.90±0.52 cases and 85.0±9.0 days per 100 workers) as well as the diseases of bone and muscular system (3.54±0.67 cases and 55.2±12.9 days per 100 workers), and diseases of digestive system (3.11±0.44 cases and 45.9±6.2 days of 100 workers) and injuries, poisonings and some other consequences of the influence of the external factors (3.02±0.40 cases and 48.8±10.3 days per 100 workers). Indices of the frequency and severity showed a tendency to fall. The index of diseases prevalence showed on average annually decreasing by 6.7 cases per 100 workers (R2 = 0.95), and an index of the duration of diseases for 77.0 days per 100 workers (R2 = 0,95). The meat processing plants suffered from economic losses because of the temporary disability of workers in the amount of 1892434.25 lei/107009.6 dollars. The obtained data indicate the need for the development and implementation of preventive measures.

Hygiene and Sanitation. 2019;98(3):280-287
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HYGIENE OF CHILDREN AND ADOLESCENTS

Hygienic evaluation of innovative educational technologies in primary school

Kuchma V., Tkachuk E., Shisharina N., Podlinyaev O.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):288-293
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Smoking prevalence and awareness of the detriment of tobacco smoking among students in Medical University

Prokhorov N., Shashina E., Semenovykh L., Makarova V., Kozeeva E.

Аннотация

Introduction. A high level of tobacco use among medical workers is registered in Russia. The adherence to this bad habit can undermine the medical professionals’ authority and reduce the effectiveness of the preventive work with the population.

The goal of this research was to determine the smoking prevalence among medical students, their level of awareness of health risks, and attitudes of smokers to this bad habit.

Material and methods. The survey concerning the prevalence and attitudes towards smoking was conducted among the students of the medical faculty of the Sechenov University. Students were asked about biographical data, health status at the time of the survey, attitudes towards healthy lifestyles and smoking, the respondents’ awareness of the detriment of tobacco smoking, attitudes to the anti-smoking campaign. A separate block of questions was addressed to smokers (smoking experience, smoking intensity, reasons for initiation).

Results. Of the 531 respondents, 18.0% were smokers at the time of the survey, 9.4% were former smokers, 72.5% never smoked. 59.6% of smokers had low smoking intensity. 3.2% of smokers had high smoking intensity. Smoking experience in both sex groups averaged 4.56 years. The main reasons for students’ initiation to smoking were curiosity (27.8%), the influence of the closest active smoking environment (21.5%), as well as existing problems in the family and the educational process (16.7%). Most of the students were informed about the negative effects of smoking and 82.7% of current smokers planned to give up smoking. 94% of smokers believed they to need professional help to stop smoking.

Discussion. The prevalence of smoking among students at Sechenov University is comparable to the data of the Global Survey of Medical Students.

Conclusions. Smoking is still common among medical students. The training of future health care workers in knowledge and skills to stop smoking should be carried out within an additional curriculum in a medical university.

Hygiene and Sanitation. 2019;98(3):294-300
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Modern specific features of the physical development of school students of Yekaterinburg

Lipanova L., Babikova A., Nasybullina G., Popova O.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):301-307
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Comparative analysis of the physical development of schoolchildren of 7-10 years in urban and rural areas

Saldan I., Pashkov A., Zhukova O.

Аннотация

The study assessed the physical development of rural and urban children aged of 7-10 years in the Altai Territory for somatometric and physiometric indices (height, body weight, chest circumference, vital capacity of lungs, dynamometry, arterial pressure). Somatometric indices of the physical development in rural children of primary school level have been established to be statistically significantly higher than similar indices of urban children in boys and girls. The evaluation of physiometric indices in groups of rural and urban children revealed another trend. Indices of the right-hand muscle strength, the vital capacity of lungs, arterial pressure (systolic and diastolic) by 10 years in urban children begins to exceed these indices of rural peers. The revealed differences in the physical development of rural and urban children show a different combination and a share of the influence of environmental factors on the schoolchildren’s organism.

Hygiene and Sanitation. 2019;98(3):308-313
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DYNAMICS OF THE REGULATORY ADAPTIVE STATUS OF STUDENTS TRAINING WORKING OCCUPATIONS

Kiyok O., Pokrovskiy V.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):314-318
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FOOD HYGIENE

Features of the chemical composition of the diet and nutritional status of indigenous and newcomers in the Russian Arctic

Baturin A., Pogozheva A., Keshabyants E., Soto S., Kobelkova I., Kambarov A.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):319-323
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PREVENTIVE TOXICOLOGY AND HYGIENIC STANDARTIZATION

The seasonal variations of carbon tetrachloride toxicity

Rakitskii V., Skupnevskii S.

Аннотация

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.

Hygiene and Sanitation. 2019;98(3):324-327
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To the mechanism of seasonal variations in carbon tetrachloride toxicity

Skupnevskii S.

Аннотация

Introduction. Seasonal biorhythms can modify the toxic effect of xenobiotics. Natural fluctuations in hormone levels in the blood which can modify the metabolic processes in the liver can be the base of one of the mechanisms in this phenomenon. The study of the effector role of testosterone in seasonal chrono-reactivity can reveal one new link in the pathogenesis and will improve health risk assessment, especially in patients taking hormone therapy. 

The aim of the study was to reveal the role of testosterone in the mechanisms of chrono-reactivity the toxic effect for carbon tetrachloride in warm-blooded animals. 

Material and Methods. Studies were conducted on adult male Wistar rats, divided into negative control groups, a model with CCl4-induced toxic hepatitis, and experimental in which CCl4 exposure was carried out following a preliminary 7-day course of testosterone administration. Direct and total bilirubin, cholesterol, alkaline phosphatase, AlAT and AsAT, hydroperoxide and malondialdehyde were determined by standard methods. The experiment was repeated twice: both in winter and spring. 

Results. The amplitude of the damage to the structures and functions of hepatocytes from a single injection of the same poison dosage in winter and spring manifested in varying degrees, revealing the modulatory role of biological rhythms. Under premedication with testosterone, a similar tendency was observed in both series of the experiment (winter, spring): the toxic effect of CCl4 increased. This was recorded by the following biochemical changes: bilirubin increased by 55%, cholesterol - 19%, alkaline phosphatase - 12%, AlAT - 17%, AsAT - 35%, hydroperoxide - 29%, and malonic dialdehyde slightly (relative to groups with model toxic hepatitis). 

Conclusion. The male sex hormone regulating the metabolic activation of cytochromes in hepatocytes performing biotransformation is one of the effector links in the seasonal chrono-reactivity phenomena. The discovery of the whole mechanism will allow developing an effective system of chronoprophylaxis and reducing the risks of toxic poisoning in individuals during periods of maximum chrono-reactivity.

Hygiene and Sanitation. 2019;98(3):328-331
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METHODS OF HYGIENIC AND EXPERIMENTAL INVESTIGATIONS

Influence of single-walled carbon nanotubes ingestion by rats on their integral and biochemical indices

Shipelin V., Shumakova A., Soto K., Selifanov A., Sidorova Y., Masyutin A., Chernov A., Gmoshinski I., Khotimchenko S.

Аннотация

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 1st to the 5th 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.

Hygiene and Sanitation. 2019;98(3):332-338
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Clinical assessment of oral debridement and teeth bleaching safety in patients with teeth abfractions and gingival recession

Vlasova N., Prokhorov N., Kuznetsov S., Danilina A., Nikolashvili N., Mnatsakanyan K.

Аннотация

Introduction. The most of dental practitioners have some doubts about teeth bleaching safety in patients with teeth abfractions and gingival recession. 

Aim. Assessment of professional oral debridement and teeth bleaching safety in patients with teeth abfractions and gingival recession. 

Material and methods. Randomized controlled trial was done in two groups of 30 patients with teeth abfractions and gingival recession. In group 1 oral debridement and professional dental bleaching were performed. Abfractions and recessions were isolated with a liquid dam. In group 2 oral debridement was made. The vertical size of recession, Tooth Wear Index and Schiff air sensitivity index were evaluated. 

Results. After 12 months the enlargement of wedge defects was pronounced in 5 teeth in group 1 and in 7 teeth in group 2. The enlargement of the gingival recession was marked in 6 teeth in group 1 and in 8 teeth in group 2. No statistical difference between groups was seen. In group 1 after teeth bleaching the sensitivity was present in 240 teeth (40%), after 14 days amount of teeth with sensitivity reduced to 110 (18.3%). In group 2 after oral debridement, the sensitivity was present in 250 teeth (41.7%), after 14 days amount of teeth with sensitivity reduced to 239 (39.8%). 

Conclusion. The teeth bleaching has no effect on dental abfractions and gingival recession.

Hygiene and Sanitation. 2019;98(3):339-342
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Methodical support for control over the concentration of persistent organic pollutant hexachlorobenzene in blood

Nurislamova T., Ulanova T., Popova N., Maltseva O.

Аннотация

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%.

Hygiene and Sanitation. 2019;98(3):343-348
pages 343-348 views