Introduction: The relevance of the study is determined by the national goals of strategic development providing for sustainable population growth and an increase in active life expectancy, primarily in demographically disadvantaged areas to which most of the regions of the Russian Arctic Zone belong.

Objective: To assess changes in the demographic structure of the Murmansk Region, one of the most industrially developed regions of the Russian Arctic, and the loss of its labor potential in 1989–2019 in order to substantiate the necessity to consider these changes for better planning of health care and adjusting the resource provision of the regional health care system.

Materials and methods: We studied demographic characteristics of the population residing in administrative areas of the Murmansk Region with the main town-forming metals and mining enterprises by comparing data for 1989 with those for the years 1999, 2009, and 2015–2019 to establish trends in medical demography situation. The average age of the population was estimated as the arithmetic mean based on distribution of the population by age groups.

Results: We established a significant decrease in the size of population of the Murmansk Region in 1989–2019 (by 34.8 %) accompanied by changes in the demographic profile. The increase in the average age of the population was attributed to the sharp decline in the child population, a decrease in the number of people of working age (16–59 years), and a significant increase in the population of older age groups. Changes in the age structure of the population had a significant effect on the old age dependency ratio, which demonstrated a 2.7 and 3.2-fold increase over the three 1989-to-2019 decades in the region and its industrial monotowns, respectively.

Conclusion: The negative structural demographic trend resulted in a pronounced regressive regional age and sex pyramid, which by 2019 had a characteristic unstable shape with a relatively narrow base and a slope of its top to the left due to the significant predominance of the female population in the older age group. The observed changes in the demographic profile of the population suggest the need to consider this trend when planning local social policy including the volume and resource provision of health care services.

Background: A man is constantly exposed to numerous environmental factors, including meteorological conditions of the earth and space weather. The study of human health effects of these factors is of increasing interest both for science and practice.

Objective: To compare instrumental and computational methods for assessing the Earth’s magnetic field in selected territories for further identification of priority natural and climatic factors and development of region-specific measures for adaptation of the local population to climate change, which should be taken into account when conducting social and hygienic monitoring.

Methods: Instrumental measurements of the Earth’s magnetic field strength were carried out in the Moscow, Voronezh, Rostov, and Krasnodar regions of the Russian Federation in August 2020. The total number of measurements was at least 15 at each point. The studies were conducted in accordance with the existing approved standard.

Results and discussion: The study areas were selected at different latitudes (from north to south) determining natural and climatic conditions of these regions. Results of instrumental measurements demonstrated the absence of significant differences between values of the Earth’s magnetic field strength at daytime and at night, possibly due to the measurement error of the MTM-01 three-component magnetometer, and ranged from 37.1 to 40.51 A/m. We observed an increasing northward trend in the Earth’s magnetic field strength (from the Krasnodar to Rostov, Voronezh, and Moscow regions). The estimated values of the magnetic field strength varied from 39.9 to 42.19 A/m. Our findings correlate with previously estimated values of the Earth’s magnetic field.

Conclusions: We conducted instrumental studies complying with existing models for estimating the Earth’s magnetic field strength, thus enabling application of our estimates in scientific research

Introduction: Extensive measures are taken in the Russian Federation to reduce cancer incidence and mortality in the population but the proportion of incident cases in advanced stages is still large while correct registration of deaths and diseases remains a challenge.

Our objectives were to study the incidence of malignant neoplasms in the Leningrad Region, to establish territories at risk, and to analyze carcinogenic risk factors associated with environmental conditions in these territories.

Materials and methods: We used data of the Federal Statistical Observation Forms No. 7 “Information on Malignant Neoplasms”, No. 12 “Information on the Number of Diseases Registered in Patients Living in the Service Area of a Medical Organization”, No. 18 “Information on the Sanitary Condition of the Subject of the Russian Federation”, and information on the size of population by sex and age in the Leningrad Region and its districts for 2008–2018. We applied a direct method of standardizing incidence rates by age, analyzed the dynamics of incidence, and estimated statistical significance of differences in the incidence rates between the territories of comparison.

Results: Cancer incidence in the Leningrad Region was lower than that in Russia. In 2008–2018, the highest rates were registered in the Kirishsky and Podporozhsky districts. In the Podporozhsky district, the standardized incidence rate in 2018 was 328.1 cases per 100,000 population or 1.79 times higher than the regional average, while the average rate for 2008–2018 exceeded the regional average by 1.36 times. The Kirishsky district ranked second by the incidence of malignant neoplasms in the Leningrad Region in 2018 (241.4 cases per 100,000 population or 1.32 times higher than the regional average), while the average rate for 2008–2018 exceeded the regional one by 1.47 times.

Conclusions: Additional research is necessary to establish the causes of high cancer incidence rates in the Kirishsky and Podporozhsky districts of the Leningrad Region.

Introduction: Current legislation permits a phased achievement of drinking water quality standards by making decisions on temporary deviations from hygienic standards for the period of design, construction, and/or upgrade of water supply facilities.

Objective: To substantiate the mechanism for coordinating temporary deviations of concentrations of certain chemicals in drinking water from hygienic standards for the period of implementing measures for water quality improvement.

Materials and methods: We applied methods of sanitary and epidemiological expert examination and assessment and the method of system analysis to review and study current regulations, results of laboratory testing of water quality in centralized cold water supply systems for 2011–2019, and action plans of 83 constituent entities of the Russian Federation for improvement of tap water quality.

Results: We established that violation of hygienic standards was most often registered for aluminum, boron, bromine, iron, silicon, lithium, magnesium, manganese, sodium, and chloroform. Hygienic requirements for tap water quality determine necessary technological solutions to be implemented at water treatment facilities; yet, their implementation requires a certain amount of time and might cause temporary tap water quality deterioration making it necessary to agree with the local bodies in charge of federal sanitary and epidemiological surveillance a phased transition to eliminating threat to public health from poor quality drinking water.

Conclusions: The authors propose an algorithm for conducting a risk assessment and a mechanism for decision making on temporary deviations.

Introduction: Polymer products have become inexpensive, convenient and widely used in all spheres of everyday life recently. Microplastics are found in seawater, wastewater, fresh water, foodstuffs, and air. Over the past few years, the presence of microplastics in treated tap and bottled water has been reported, raising questions and concerns about their potential human health effects.

Objective: To summarize and systematize the results of studying health effects of exposure to microplastics in potable water.

Materials and methods: A literature review was done based on ten topical articles and reviews published in 2014–2021 out of 64 sources found in the PubMed and Scopus international databases and the Russian Science Citation Index (RSCI).

Results and conclusions: Generalization and systematization of the published research data demonstrated the lack of strong evidence to draw conclusions about human health effects of microplastics. Information on toxicokinetics and toxicodynamics of ingested microplastic particles is absent just like the studies of the most common shapes and sizes of plastic particles and health risks from exposure to such particles in drinking water.

Introduction: With the spread of laser technologies in various spheres of human activity, the number of exposures to laser radiation of a wide range of users unfamiliar with specifics of its health effects, including those in everyday life, has increased, thus resulting in an increased number of traumas in the general population in recent years.

Objectives: To search for data on the biological mechanisms of action of visible laser radiation in Russian and foreign scientific literature and to analyze adverse health effects of this exposure encountered in domestic and international practice.

Methods: We searched for Russian and foreign full-text open access literary sources in Russian Science Citation Index (RSCI) and PubMed databases of biomedical publications for 1969–2019 and selected the most appropriate ones for review.

Results: Both Russian and foreign researchers note that human exposure to laser radiation induces specific and non-specific responses at all tissue levels of organization. The extent and nature of developing morphological changes depend on the radiation wavelength, exposure time, power, energy and its density per unit of the irradiated surface.

Conclusions: Our findings suggest that portable laser pointers and powerful laser projectors may cause retinal damage, traumatic macular holes and, in some cases, loss of vision. Despite frequently registered good visual recovery, general availability of commercial laser devices poses potential danger, especially for minors, and substantiates the need to raise public awareness of laser safety.

Introduction: Residents of modern cities and settlements are constantly exposed to noise. Excessive noise mainly attributed to road traffic ranks high among the complaints of the general population about living conditions. Careful selection of measuring sites plays an important role in monitoring noise exposure of the population. Current regulations and guidelines set the requirements for measuring and evaluating noise levels in a territory but provide no common approach to determining and selecting priority areas and noise measurement points, to establishing and substantiating appropriate observation periods, and to assessing health risks based on the exposure data.

Materials and methods: In situ measurements were taken in residential areas of the historical center (four observation groups with 12 addresses) and new districts of the city (two observation groups with six addresses). Noise levels were measured at three points per address with three 5-minute measurements at a height of 1.5 ± 0.1 m above the ground taken per point. Points with the highest noise exposure levels were selected for organization of acoustic monitoring.

Results and discussion: Six major observation groups were formed at 18 urban addresses. The results of measurement showed that statistically significant comparable levels of equivalent and maximum sound were registered in each group based on the same criteria and standard indicators. Grouping of addresses with similar or identical characteristics of observation zones will enable establishing noise exposures without conducting full-scale measurements. Additional observation groups can be formed in the presence of other indicators. Grouping of priority zones by location in observation groups will help register noise levels with minimal effort.

Conclusions: Priority zones, points, periods of monitoring and surveillance in observation groups were established and justified. The findings served as the basis for elaboration of method approaches to monitoring and surveillance of road traffic noise exposure. Application of these approaches will contribute to increasing the efficiency of monitoring noise exposures of the population.

Introduction: All components of the power supply system are sources of electric and magnetic fields of industrial frequency of 50 Hz, both posing risks to human health. Estimation of predicted magnetic field levels from switchboards and transformers inside buildings is challenging and implies the importance of full-scale measurements of electromagnetic fields from built-in electrical equipment.

Objectives: To establish the levels of 50 Hz electromagnetic fields during operation of built-in electrical installations in industrial, public, and residential premises.

Materials and methods: We studied 50 Hz electromagnetic fields generated by electrical installations located in buildings. EMF levels were measured near transformers, switchboards, and switchgear. The electromagnetic situation in the rooms above the electrical equipment was investigated. The assessment of EMF levels was carried out in accordance with the current hygienic standards.

Results: The intensity of electric fields near the equipment and in the surveyed premises was significantly lower than that of magnetic fields. The excess of maximum permissible levels at workplaces of operators servicing EMF sources in residential buildings was not detected. In the rooms of public buildings located above electrical installations, measured values of magnetic field induction ranged from 0.18 to 31 µT. The intensity of magnetic fields depended on the current load and the distance from EMF sources.

Discussion: Electromagnetic field intensity depends on specifications of equipment, current loads, and distances from the sources of electromagnetic fields. Induction of 50 Hz magnetic fields in adjacent rooms may exceed hygienic standards set for residential and public buildings. Additional adverse factors include instability of magnetic fields caused by current load changes and significant magnetic field gradients in premises.

Introduction: Owing to the rapid development of digital technologies, most people nowadays are working indoors while using no machinery or equipment and being unexposed to volatile industrial chemicals. Yet, people staying inside for too long often complain of poor indoor air quality and microclimate.

Our objective was to study air pollutants in a simulation experiment with continuous human occupancy inside unventilated confined spaces.

Materials and methods: Up-to-date sensitive analytical techniques, such as photoionization, laser nephelometry, gas-phase chemiluminescence, spectrophotometry, high-performance liquid chromatography with diode array detection (HPLCDAD) and gas chromatography–mass spectrometry (GC-MS), were used to determine indoor air pollutants.

Results: We compared changes in airborne concentrations of nitrogen oxides, prop-2-enenitrile, acetaldehyde, benzene, but- 2-enal, airborne particulate matter (PM2,5 and PM10), methylbenzene, 2-methylbuta-1,3-diene, formaldehyde, prop-2-en- 1-al, carbon oxide and dioxide following 1.5, 3.0, and 4.5 hours of stay of volunteers in a 15.9 m2 room ((4.0 m2 per person; a 2.55 m ceiling height) against background levels. The established human occupancy-related priority pollutants included acetaldehyde, formaldehyde, prop-2-en-1-al, and carbon dioxide. Laboratory testing showed the presence of 83 volatile and semivolatile organic chemicals in the unventilated room, among which aromatic hydrocarbons, esters and aldehydes prevailed.

Conclusion: Our findings could be useful for designing ventilation systems in confined spaces and optimizing the workbreak schedule during the working hours.

Introduction: Intensification of economic activities in the northern regions of Russia requires a better understanding of the combined health effect of cold environment and occupational risk factors.

Objective: To assess the risk of developing health disorders in gas and electric welders exposed to low and normal workplace temperatures.

Materials and methods: We conducted a comparative analysis of working conditions and health status of welders at two enterprises. The main cohort included 310 workers exposed to welding fumes and cold microclimate in an underground mine. The control cohort included 282 employees of a railcar manufacturing facility performing their functional duties in workshops with acceptable microclimate parameters.

Results: According to the results of periodic medical examinations, 499 chronic diseases were diagnosed in welders of the main cohort against 230 among the controls. Compared to the reference cohort, underground welders were at higher risk of developing diseases of the digestive system (RR = 2.63; CI: 1.47–4.70; p = 0.0006), genitourinary (RR = 6.55; CI: 1.51–28.4; p = 0.004), musculoskeletal (RR = 1.50; CI: 1.14–1.97; p = 0.003), and nervous systems (RR = 5.29; CI 1.19–23.4; p = 0.014), skin (RR = 3.85; CI: 1.61–9.18; p = 0.001), respiratory organs (RR = 3.23; CI: 1.84–5.69; p < 0.001), as well as infectious and parasitic diseases (RR = 8.61; CI: 2.03–36.5; p = 0.0004). Thus, the number of healthy workers was smaller while the number of workers suffering from two or more chronic diseases was bigger in this cohort (p < 0.001).

Conclusions: The welders working in cold environment were significantly less healthy than those working in normal workplace temperatures. The results necessitate the development of additional measures of disease prevention for this category of employees.

Background: The problem of protecting and maintaining health of workers in the microelectronics industry exposed to adverse occupational factors including tension and overstrain of the muscles of the upper extremities and visual strain, gains special relevance.

Objective: Introduction of the developed and patented low-level laser therapy techniques to recover functions of vision and the musculoskeletal system impaired in the course of work.

Materials and methods: The study involved 65 chip assemblers aged 26–41 years. Their eyes, the back of the hands, and the collar area were exposed to low-level laser radiation from the red region of the spectrum. All employees were examined by a neurologist and a surgeon and their working conditions were evaluated. The accommodation apparatus was tested using an AKA-01 type accommodation meter.

Results: After five 10-minute sessions, we registered an increase in the volume of absolute accommodation during the observation period before and after the work shift by 28 % and 19 %, respectively. On subsequent days of observation, we noted an increase in the accommodation during 10 days, followed by a decrease by the 30th day of observation. Application of preventive techniques helped eliminate spinal cord disorders in all workers. Blood circulation in fingers increased by 66 % compared to the initial condition.

Discussion: Low-level laser therapy improves blood supply, intensifies redox processes in the retina of the eye, skin cells, and blood vessels.

Conclusions: Low-level laser radiation of the red region of the spectrum relieves the spasm of accommodation and normalizes the efficiency of the accommodation apparatus. Such laser therapy helps eliminate spinal cord disorders and improve blood circulation. Introduction of the developed techniques can prevent occupational diseases and reduce disability in patients.

Introduction: Occupational polyneuropathy of upper extremities induced by physical overload is often registered among workers of various occupations. Yet, modern science lacks up-to-date results of a comprehensive assessment of the condition of such patients in terms of occupational disease severity and the presence of concomitant non-occupational diseases.

Objective: To establish severity of the occupational disease and comorbidity status in workers of various occupations, to assess their significance for planning measures aimed at professional rehabilitation of patients.

Materials and methods: Severity of occupational polyneuropathy and comorbidity status were established in agricultural, construction, industrial, and mining workers.

Results: In all cohorts of workers, occupational polyneuropathy is generally registered in middle-aged and elderly people usually experiencing moderate symptoms; in most cases, it is combined with other occupational diseases of the musculoskeletal system and the peripheral nervous system. Miners suffering from this type of polyneuropathy are often diagnosed with chronic industrial bronchitis. Of non-occupational disorders, ischemic heart disease, hypertension, dorsopathies, and osteoarthritis of various sites prevail in all occupational cohorts and limit the ability of patients to work.

Discussion: The severity of polyneuropathy and comorbidity status of patients from different occupational cohorts vary and this fact shall be taken into account when planning medical and professional rehabilitation of workers, which is usually hampered due to imperfection of the current regulations on examining professional suitability, according to which occupational peripheral neuropathy cases shall not stop working in conditions of physical overload.

Conclusions: It is critical to attend to the flaws of current regulations, which impede effective rehabilitation of patients with occupational polyneuropathy and other associated diseases.