Threats of radioactive radiation: features of impaction on the environment and human health

According to the Kirovohrad Oblast Oncology Service, in 2021 the incidence of malignant tumors increased from 468.4 per 100,000 population in 2020 to 478.2 in 2021, i.e. by 2.1%, and significantly exceeded the average Ukrainian figure in 2020 - 348.4 [8].

The increase was in lip cancer (3.8 vs. 2.5 in 2020), colon cancer (27.5 vs. 26.2 in 2020), skin melanoma (9.9 vs. 8.4 in 2020), esophageal cancer (5.4 vs. 4.2 in 2020), gastric cancer (24.4 vs. 23.4 in 2020), lung cancer (48.1 vs. 44.8 in 2020), breast cancer (83.8 vs. in 2020) and ovaries - (23.4 vs. 20.3 in 2020) per 100,000 female population, skin cancer (64.3 vs. 63.7 in 2020), cervical cancer 38.2 vs. 34.7 in 2020 per 100,000 female population), prostate (61.2 vs. per 100,000 male population in 2020), malignant lymphoma (10.4 vs. 9.4 in 2020) [9].

It should be noted that over the last decade the incidence rate in the region increased by 17.7% (478.2 in 2021 against 406.3 in 2020), and in Ukraine - by 5.2% (348.4 in 2021 against 331.1 in 2020).

In the structure of cancer among the entire population of the region are:

First place - skin cancer 64.3 per 100 thousand population, or 13.5%;

P place - cancer of the trachea and lungs 48.1 per 100 thousand population, or 10.6%;

W place - breast cancer 45.7 per 100 thousand population, or 9.5%;

Among the female population:

First place - breast cancer 83.8 per 100 thousand female population, or 17.6%;

P place - skin cancer 72.8 per 100 thousand female population, or 15.3%;

W place - uterine cancer 42.3 per 100 thousand female population, or 8.9%;

Among the male population:

And the place - lung cancer 80.4 per 100 thousand male population, or 16.7%;

Second place - prostate cancer 61.2 per 100 thousand male population, or 12.7%.

Third place - skin cancer 54.4 per 100 thousand male population, or 11.3%.

The incidence of malignant tumors ranges from 590.5 per 100 thousand population in Kropyvnytskyi to 293.9 in Ustyniv district. The highest incidence rates were registered in Kropyvnytskyi - 590.5. Here are the contingents of patients with malignant neoplasms (Table 2) [6].

According to the literature, uranium in microquantities (10-5 - 10-6%) is present in all tissues of plants, animals and humans. U enters the human body with food and water to the gastrointestinal tract (GIT), with air - in the respiratory tract, as well as through the skin and mucous membranes. The medical consequences of uranium exposure are due to its chemical and radiological properties. For uranium and radon decay products, the critical organs are the lungs and upper respiratory tract, as well as red bone marrow. Uranium is often referred to in the literature as «kidney poison». The skeleton contains more than 90% of uranium deposited in the body. Relatively recently, the accumulation of uranium has been experimentally established not only in the kidneys and bones, but also in the testes, lymph nodes and brain.

The effects of radon on the human body are also diverse. Having the ability to dissolve well in blood and lymph, it is concentrated in vital organs. Its content per unit volume of the body is 50% of the content in the ambient air. The severity of pathological changes in the body depends on age and the accumulated dose of radon. Among the radon-dependent pathology are lesions of the lungs, cardiovascular, nervous, musculoskeletal systems, reproductive function, hormonal changes. According to Serdyuk A. M. and co-authors, chronic exposure to radon and other radionuclides on the human body leads to changes in the respiratory system, cardiovascular system, digestive system and genitourinary system. Thus, in the city of Zhovti Vody the incidence of angina exceeds the regional level by 2.15 times; diseases of the endocrine organs - 2.15 times; diseases of the blood and blood-forming organs - 1.55 times.

It is known that the immune system has the highest radiation sensitivity in the body. Therefore, the radiation effect on the human body is primarily the development of acquired immunodeficiency states of various nature and severity, which, in turn, are the basis for the emergence of various human pathologies. It was found that the equivalent equilibrium volume activity of radon in 43% of apartments where the surveyed persons lived exceeded the control value - 200 Bq / m³. The contribution of radon to the total radiation dose in most cases was more than 80% [10]. Immunological examination of the population living in these conditions revealed a significant prevalence of hyposuppressive states, as well as the predominance of immunodeficiency states with lesions of the T-link of the immune system and phagocytic leukocytes of moderate nature. The obtained data indicate the presence of the initial stages of immunocompromising the population and the need for individual treatment and mass preventive immunocorrection to reduce immune-dependent morbidity.

The most important aspect of the problem is the impact on the health of children who are particularly sensitive to the effects of radon and on this basis belong to a critical group. Physical development is characterized by disproportion, from an early age. In school-age children, acceleration processes have changed to deceleration with trophic insufficiency, and in some cases not retardation. The combination of these factors is defined as the syndrome of environmental maladaptation.

In recent years, a considerable amount of work has been published proving the neurotoxicity of uranium, in contrast to the common notion that uranium targets only the kidneys, liver, and bone (depending on the route of entry and form of uranium compounds). These studies indicate that the brain is also a target organ.

Psychopathological factors worsen the course of somatic diseases, complicate their clinical picture, increase the frequency of calls for medical care, reduce the ability of patients to self-care and their commitment to treatment and overall quality of life. Pastel R. reports that the primary long-term effect of the Chernobyl accident was the formation of psychological disorders in the liquidators of the accident, evacuated residents of radioactively contaminated areas, as well as residents of «clean» areas [10]. Psychoneurological syndromes with unexplained physical symptoms, including fatigue, sleep disturbances and mood swings, impaired memory and concentration, and frequent muscle and joint pain have been reported. The author does not associate these syndromes, which resemble chronic fatigue syndrome and fibromyalgia, with the radiation effect, as they were observed in residents of both contaminated and low-radiation areas, but considers it a manifestation of radiophobia inherent in this group of patients.

Thus, given the proven impact of radiation on the environment and somatic morbidity, it is obvious the need to study various aspects of the impact of NFC enterprises on the psycho-emotional status of residents located in regions of production of these enterprises [11, 12].

Conclusions

Thus, conducting research, we can say that the issue of human protection from the negative effects of ionizing radiation arose almost simultaneously with the discovery of X-rays and radioactive decay. This is due to the following factors: first, the extremely rapid development of the use of open radiation in science and practice, and secondly, the detection of the negative effects of radiation on the body. Radiation safety measures are used in enterprises and, as a rule, require a range of various protective measures, depending on the specific conditions of work with sources of ionizing radiation and, above all, the type of radiation source.

Closed are any sources of ionizing radiation, the device of which excludes the penetration of radioactive substances into the environment under the conditions of their operation and wear. These are gamma installations for various purposes; neutrons, beta and gamma emitters; X-ray machines and charged particle accelerators. When working with closed sources of ionizing radiation, personnel may only be exposed to external radiation.

Protective measures to ensure the conditions of radiation safety in the use of sealed sources, based on knowledge of the laws of propagation of ionizing radiation and the nature of their interaction with matter. The main ones are: the dose of external radiation is proportional to the intensity of radiation and exposure time; the intensity of radiation from a point source is proportional to the number of quanta or particles that occur in it per unit time, and inversely proportional to the square of the distance; the intensity of the radiation can be reduced with the help of screens.

From these laws follow the basic principles of radiation safety: reducing the power of sources to a minimum («protection by quantity»); reduction of time of work with a source («protection of time»); increasing the distance from sources to people («protection of distance»); shielding of radiation sources with materials that absorb ionizing radiation («screen protection»).

Lead and uranium are best for protection against X-rays and gamma radiation. However, due to the high cost of lead and uranium, screens made of lighter materials can be used - leaded glass, iron, concrete, reinforced concrete and even water. In this case, naturally, the equivalent screen thickness increases significantly.

To protect against beta streams, it is advisable to use screens that are made of materials with a low atomic number. In this case, the output of bremsstrahlung is small. Organic glass, plastic, and aluminum are usually used as screens to protect against beta radiation. Open sources are those sources of ionizing radiation, the use of which may allow the entry of radioactive substances into the environment.

At the same time there can be not only external, but also additional internal irradiation of the personnel. This can occur when radioactive isotopes enter the working environment in the form of gases, aerosols, and solid and liquid radioactive waste: Sources of aerosols can be not only production operations, but also contaminated work surfaces, clothing and footwear.

Basic principles of protection: use of protection principles used when working with radiation sources in a closed form; sealing of production equipment in order to isolate processes that may become sources of radioactive substances in the environment; planning activities; application of sanitary means and equipment, use of special protective materials; use of personal protective equipment and sanitation of personnel; compliance with the rules of personal hygiene; cleaning of surfaces of building structures, equipment and personal protective equipment from radioactive contamination; use of radioprotectors (biological protection).

Radioactive contamination of overalls, personal protective equipment and skin of personnel should not exceed the permissible levels provided by the Radiation Safety Standards NRBU-97.

In case of contamination with radioactive substances, personal clothing and footwear must be decontaminated under the control of the radiation safety service, and in case of impossibility of decontamination they should be disposed of as radioactive waste. X-ray radiological procedures are among the most effective methods for diagnosing human diseases. This determines the further increase in the use of X-ray and radiological procedures or their use on a larger scale. However, patient safety concerns require that we minimize exposure levels, as exposure to ionizing radiation at any dose is associated with an additional, non-zero risk of remote, stochastic effects.

Currently, in order to reduce individual and collective radiation doses of the population through diagnostics, organizational and technical measures are widely used: as an exception, unfounded (without evidence) research; changing the structure of research in favor of those that give a lower dose of load; introduction of new equipment equipped with modern electronic equipment for enhanced visual imaging; the use of screens to protect areas of the body to be studied, etc.