It is difficult to overestimate the influence of the sun's light on a person - under its action, the most important physiological and biochemical processes are launched in the body. The solar spectrum is divided into infrared and visible parts, as well as the most biologically active ultraviolet part, which has a great impact on all living organisms on our planet. Ultraviolet radiation is a short-wave part of the solar spectrum that is imperceptible to the human eye, which has an electromagnetic character and photochemical activity.

Due to its properties, ultraviolet is successfully used in various areas of human life. UV radiation has received wide use in medicine, since it is able to change the chemical structure of cells and tissues, having a different effect on humans.

UV wavelength range

The main source of UV radiation is the sun. The share of ultraviolet in the total flow of sunlight is not constant. It depends on:

• time of day;
• time of year;
• solar activity;
• geographic latitude;
• the state of the atmosphere.

Despite the fact that the celestial body is far from us and its activity is not always the same, a sufficient amount of ultraviolet reaches the Earth's surface. But this is only its small long-wavelength part. Short waves are absorbed by the atmosphere at a distance of about 50 km from the surface of our planet.

The ultraviolet range of the spectrum, which reaches the earth's surface, is conditionally divided by wavelength into:

• far (400 - 315 nm) - UV - A rays;
• medium (315 - 280 nm) - UV - B rays;
• near (280 - 100 nm) - UV - C rays.

The effect of each UV range on the human body is different: the shorter the wavelength, the deeper it penetrates through the skin. This law determines the positive or negative effect of ultraviolet radiation on the human body.

Near-range UV radiation most adversely affects health and carries the risk of serious illnesses.

UV-C rays should be scattered in the ozone layer, but due to poor ecology, they reach the surface of the earth. Ultraviolet rays of range A and B are less dangerous, with strict dosing, radiation of the far and medium range has a beneficial effect on the human body.

Artificial sources of ultraviolet radiation

The most significant sources of UV waves affecting the human body are:

• bactericidal lamps - sources of UV - C waves, used to disinfect water, air or other environmental objects;
• arc of industrial welding - sources of all waves of the solar spectrum;
• erythemal fluorescent lamps - sources of UV waves of the A and B range, used for therapeutic purposes and in solariums;
• industrial lamps are powerful sources of ultraviolet waves used in manufacturing processes to cure paints, inks or cure polymers.

The characteristics of any UV lamp are the power of its radiation, the range of the wave spectrum, the type of glass, the service life. From these parameters depends on how the lamp will be useful or harmful to humans.

Before irradiation with ultraviolet waves from artificial sources for the treatment or prevention of diseases, one should consult with a specialist to select the necessary and sufficient erythemal dose, which is individual for each person, taking into account his skin type, age, existing diseases.

It should be understood that ultraviolet is electromagnetic radiation, which has not only a positive effect on the human body.

A bactericidal ultraviolet lamp used for tanning will bring significant harm, not benefit to the body. Only a professional who is well versed in all the nuances of such devices should use artificial sources of UV radiation.

The positive effect of UV radiation on the human body

Ultraviolet radiation is widely used in the field of modern medicine. And this is not surprising, because UV rays produce analgesic, soothing, anti-rachitic and anti-spastic effects. Under their influence occurs:

• the formation of vitamin D, necessary for the absorption of calcium, the development and strengthening of bone tissue;
• decreased excitability of nerve endings;
• increased metabolism, because it causes the activation of enzymes;
• vasodilation and improved blood circulation;
• stimulating the production of endorphins - "happiness hormones";
• increase in the speed of regenerative processes.

The beneficial effect of ultraviolet waves on the human body is also expressed in a change in its immunobiological reactivity - the body's ability to show protective functions against pathogens of various diseases. Strictly dosed ultraviolet irradiation stimulates the production of antibodies, thereby increasing the resistance of the human body to infections.

Exposure to UV rays on the skin causes a reaction - erythema (redness). There is an expansion of blood vessels, expressed by hyperemia and swelling. The decay products formed in the skin (histamine and vitamin D) enter the bloodstream, which causes general changes in the body when exposed to UV waves.

The degree of development of erythema depends on:

• UV dose values;
• range of ultraviolet rays;
• individual sensitivity.

With excessive UV radiation, the affected area of ​​the skin is very painful and swollen, a burn occurs with the appearance of a blister and further convergence of the epithelium.

But skin burns are far from the most serious consequences of prolonged exposure to ultraviolet radiation on a person. The unreasonable use of UV rays causes pathological changes in the body.

The negative impact of UV radiation on humans

Despite its important role in medicine, The health risks of UV radiation outweigh the benefits.. Most people are not able to accurately control the therapeutic dose of ultraviolet radiation and resort to protective methods in a timely manner, therefore, its overdose often occurs, which causes the following phenomena:

• headaches appear;
• body temperature rises;
• fatigue, apathy;
• memory impairment;
• heart palpitations;
• loss of appetite and nausea.

Excessive tanning damages the skin, eyes, and immune (defense) system. Perceived and visible effects of excessive UV exposure (burns of the skin and mucous membranes of the eyes, dermatitis and allergic reactions) disappear within a few days. Ultraviolet radiation accumulates over a long period of time and causes very serious diseases.

The effect of ultraviolet radiation on the skin

A beautiful even tan is the dream of every person, especially the fairer sex. But it should be understood that skin cells darken under the influence of the coloring pigment released in them - melanin in order to protect against further exposure to ultraviolet radiation. So tanning is a protective reaction of our skin to damage to its cells by ultraviolet rays. But it does not protect the skin from the more serious effects of UV radiation:

1. Photosensitivity - increased susceptibility to ultraviolet light. Even a small dose of it causes severe burning, itching and sunburn of the skin. Often this is due to the use of medications or the use of cosmetics or certain foods.
2. Photoaging. Spectrum A UV rays penetrate into the deep layers of the skin, damage the structure of the connective tissue, which leads to the destruction of collagen, loss of elasticity, and early wrinkles.
3. Melanoma - skin cancer. The disease develops after frequent and prolonged exposure to the sun. Under the influence of an excessive dose of ultraviolet radiation, malignant formations appear on the skin or old moles degenerate into a cancerous tumor.
4. Basal cell and squamous carcinoma is a non-melanoma skin cancer that is not fatal, but requires surgical removal of affected areas. It has been noticed that the disease occurs much more often in people who work under the open sun for a long time.

Any dermatitis or skin sensitization phenomena under the influence of ultraviolet radiation are provoking factors for the development of skin cancer.

The effect of UV waves on the eyes

Ultraviolet rays, depending on the depth of penetration, can also adversely affect the condition of the human eye:

1. Photophthalmia and electrophthalmia. It is expressed in redness and swelling of the mucous membrane of the eyes, lacrimation, photophobia. Occurs when safety rules are not observed when working with welding equipment or in people who are in bright sunlight in a snow-covered space (snow blindness).
2. Growth of the conjunctiva of the eye (pterygium).
3. Cataract (clouding of the lens of the eye) is a disease that occurs to varying degrees in the vast majority of people in old age. Its development is associated with exposure to ultraviolet radiation on the eye, which accumulates over a lifetime.

Excess UV rays can lead to various forms of eye and eyelid cancer.

The effect of ultraviolet radiation on the immune system

If the dosed use of UV radiation helps to increase the body's defenses, then excessive exposure to ultraviolet light depresses the immune system. This has been proven in scientific studies by US scientists on the herpes virus. Ultraviolet radiation changes the activity of cells responsible for immunity in the body, they cannot restrain the reproduction of viruses or bacteria, cancer cells.

Basic precautions for safety and protection against exposure to ultraviolet radiation

To avoid the negative effects of UV rays on the skin, eyes and health, every person needs protection from ultraviolet radiation. When forced to stay in the sun for a long time or at a workplace exposed to high doses of ultraviolet rays, it is imperative to find out if the UV index is normal. In enterprises, a device called a radiometer is used for this.

When calculating the index at meteorological stations, the following is taken into account:

• wavelength of the ultraviolet range;
• concentration of the ozone layer;
• solar activity and other indicators.

The UV index is an indicator of the potential risk to the human body as a result of exposure to a dose of ultraviolet radiation. The index value is evaluated on a scale from 1 to 11+. The norm of the UV index is considered to be no more than 2 units.

High index values ​​(6-11+) increase the risk of adverse effects on human eyes and skin, so protective measures must be taken.

1. Use sunglasses (special masks for welders).
2. In the open sun, you should definitely wear a hat (with a very high index - a wide-brimmed hat).
3. Wear clothes that cover your arms and legs.
4. On uncovered areas of the body wear sunscreen with an SPF of at least 30.
5. Avoid being outdoors, not protected from sunlight, space from noon to 4 pm.

The implementation of simple safety rules will reduce the harmfulness of UV radiation to humans and avoid the occurrence of diseases associated with the adverse effects of ultraviolet radiation on his body.

Who should not be exposed to ultraviolet light?

The following categories of people should be careful with exposure to ultraviolet radiation:

• with very light and sensitive skin and albinos;
• children and adolescents;
• those who have many birthmarks or nevi;
• suffering from systemic or gynecological diseases;
• those who had skin cancer among close relatives;
• taking certain medications for a long time (a doctor's consultation is necessary).

UV radiation is contraindicated for such people even in small doses, the degree of protection from sunlight should be maximum.

The influence of ultraviolet radiation on the human body and its health cannot be unequivocally called positive or negative. Too many factors should be taken into account when it affects a person in different environmental conditions and radiation from various sources. The main thing to remember is the rule: any human exposure to ultraviolet light should be kept to a minimum before consultation with a specialist and strictly dosed according to the doctor's recommendations after examination and examination.

Ultraviolet affects precisely living cells, without affecting the chemical composition of water and air, which exceptionally favorably distinguishes it from all chemical methods of disinfection and disinfection of water.

Recent advances in lighting and electrical engineering make it possible to ensure a high degree of reliability of water disinfection with ultraviolet rays.

What is this radiation

Ultraviolet radiation, ultraviolet rays, UV radiation, electromagnetic radiation not visible to the eye, occupying the spectral region between visible and X-ray radiation within wavelengths of 400-10 nm. The entire region of UV radiation is conditionally divided into near (400-200 nm) and far, or vacuum (200-10 nm); the last name is due to the fact that the UV radiation of this area is strongly absorbed by air and its study is carried out using vacuum spectral instruments.

Natural sources of UV radiation - the Sun, stars, nebulae and other space objects. However, only the long-wave part of UV radiation - 290 nm reaches the earth's surface. Shorter wavelength UV radiation is absorbed by ozone, oxygen, and other components of the atmosphere at a height of 30-200 km from the Earth's surface, which plays an important role in atmospheric processes.

Artificial sources of UV radiation. For various applications of UV radiation, industry produces mercury, hydrogen, xenon, and other gas-discharge lamps, the windows of which (or entire flasks) are made of materials that are transparent to UV radiation (most often, quartz). Any high-temperature plasma (plasma of electric sparks and arcs, plasma formed by focusing high-power laser radiation in gases or on the surface of solids, etc.) is a powerful source of UV radiation.

Despite the fact that ultraviolet is given to us by nature itself, it is not safe.

Ultraviolet is of three types: "A"; "B"; "WITH". The ozone layer prevents ultraviolet "C" from reaching the earth's surface. Light in the ultraviolet "A" spectrum has a wavelength of 320 to 400 nm, light in the ultraviolet "B" spectrum has a wavelength of 290 to 320 nm. UV radiation has enough energy to affect chemical bonds, including those in living cells.

The energy of the ultraviolet component of sunlight causes damage to microorganisms at the cellular and genetic levels, the same damage is done to humans, but it is limited to the skin and eyes. Sunburn is caused by exposure to ultraviolet "B". Ultraviolet "A" penetrates much deeper than ultraviolet "B" and contributes to premature aging of the skin. In addition, exposure to ultraviolet "A" and "B" leads to skin cancer.

From the history of ultraviolet rays

The bactericidal effect of ultraviolet rays was discovered about 100 years ago. The first laboratory tests of UVR in the 1920s were so promising that the complete elimination of airborne infections seemed possible in the very near future. UV radiation has been actively used since the 1930s and in 1936 was first used to sterilize the air in a surgical operating room. In 1937, the first use of UV radiation in the ventilation system of an American school dramatically reduced the incidence of measles and other infections among students. Then it seemed that a wonderful remedy had been found to combat airborne infections. However, further study of UVR and the dangerous side effects has severely limited its use in the presence of humans.

The force of penetration of ultraviolet rays is small and they propagate only in a straight line, i.e. in any working room, a lot of shaded areas are formed that are not subject to bactericidal treatment. As you move away from the source of ultraviolet radiation, the biocidal effect of its action decreases sharply. The action of the rays is limited to the surface of the irradiated object, and its purity is of great importance.

The bactericidal effect of ultraviolet radiation

The disinfecting effect of UV radiation is mainly due to photochemical reactions, which result in irreversible DNA damage. In addition to DNA, ultraviolet also affects other cell structures, in particular, RNA and cell membranes. Ultraviolet, as a high-precision weapon, affects precisely living cells without affecting the chemical composition of the environment, which is the case for chemical disinfectants. The latter property distinguishes it exceptionally favorably from all chemical methods of disinfection.

Application of ultraviolet

Ultraviolet is currently used in various areas: medical institutions (hospitals, clinics, hospitals); food industry (products, drinks); pharmaceutical industry; veterinary medicine; for disinfection of drinking, circulating and waste water.

Modern achievements in lighting and electrical engineering provided the conditions for the creation of large UV disinfection complexes. The widespread introduction of UV technology in municipal and industrial water supply systems makes it possible to ensure effective disinfection (disinfection) of both drinking water before being supplied to the municipal water supply network, and wastewater before being released into water bodies. This makes it possible to exclude the use of toxic chlorine, significantly improve the reliability and safety of water supply and sewerage systems in general.

Disinfection of water with ultraviolet light

One of the urgent tasks in the disinfection of drinking water, as well as industrial and domestic effluents after their clarification (biotreatment) is the use of technology that does not use chemical reagents, i.e. technology that does not lead to the formation of toxic compounds during the disinfection process (as in the case of using compounds of chlorine and ozonation) with simultaneous complete destruction of pathogenic microflora.

There are three sections of the spectrum of ultraviolet radiation, which have different biological effects. Weak biological impact has ultraviolet radiation with a wavelength of 390-315 nm. Antirachitic action is possessed by UV rays in the range of 315-280 nm, and ultraviolet radiation with a wavelength of 280-200 nm has the ability to kill microorganisms.

Ultraviolet rays with a wavelength of 220-280 have a detrimental effect on bacteria, and the maximum bactericidal action corresponds to a wavelength of 264 nm. This circumstance is used in bactericidal installations intended for disinfection mainly of groundwater. The source of ultraviolet rays is a mercury-argon or mercury-quartz lamp installed in a quartz case in the center of a metal case. The cover protects the lamp from contact with water, but freely transmits ultraviolet rays. Disinfection occurs during the flow of water in the space between the body and the case with direct exposure to ultraviolet rays on microbes.

The bactericidal action is evaluated in units called bacts (b). To ensure the bactericidal effect of ultraviolet irradiation, approximately 50 μb min / cm2 is sufficient. UV irradiation is the most promising method of water disinfection with high efficiency in relation to pathogenic microorganisms, which does not lead to the formation of harmful by-products, which ozonation sometimes sins.

UV irradiation is ideal for the disinfection of artesian waters

The point of view that groundwater is considered free from microbial contamination as a result of water filtering through the soil is not entirely correct. Studies have shown that groundwater is free from large microorganisms such as protozoa or helminths, but smaller microorganisms such as viruses can penetrate the soil into underground water sources. Even if bacteria are not found in the water, disinfection equipment should act as a barrier against seasonal or accidental contamination.

UV irradiation should be used to ensure that water is disinfected to microbiological quality standards, with the necessary doses being selected based on the required reduction in the concentration of pathogenic and indicator microorganisms.

UV irradiation does not form by-products of the reaction, its dose can be increased to values ​​that ensure epidemiological safety, both for bacteria and viruses. It is known that UV radiation acts on viruses much more effectively than chlorine, so the use of ultraviolet in the preparation of drinking water makes it possible, in particular, to largely solve the problem of removing hepatitis A viruses, which is not always solved with traditional chlorination technology.

The use of UV irradiation as a disinfectant is recommended for water that has already been treated for color, turbidity and iron content. The effect of water disinfection is controlled by determining the total number of bacteria in 1 cm3 of water and the number of indicator bacteria of the Escherichia coli group in 1 liter of water after its disinfection.

To date, UV lamps of the flow type have become widespread. The main element of this installation is a block of irradiators consisting of UV spectrum lamps in an amount determined by the required capacity for treated water. Inside the lamp has a cavity for the duct. Contact with UV rays occurs through special windows inside the lamp. The body of the unit is made of metal, which protects against the penetration of rays into the environment.

The water supplied to the installation must meet the following requirements:

• total iron content - no more than 0.3 mg / l, manganese - 0.1 mg / l;


• hydrogen sulfide content - no more than 0.05 mg / l;


• turbidity - no more than 2 mg / l for kaolin;


• chromaticity - no more than 35 degrees.

The ultraviolet disinfection method has the following advantages in relation to oxidative disinfection methods (chlorination, ozonation):

• UV exposure is lethal to most aquatic bacteria, viruses, spores and protozoa. It destroys the causative agents of such infectious diseases as typhus, cholera, dysentery, viral hepatitis, poliomyelitis, etc. The use of ultraviolet radiation makes it possible to achieve more effective disinfection than chlorination, especially with respect to viruses;


• disinfection with ultraviolet light occurs due to photochemical reactions inside microorganisms, therefore, its effectiveness is much less affected by changes in the characteristics of water than during disinfection with chemical reagents. In particular, the effect of ultraviolet radiation on microorganisms is not affected by the pH and temperature of the water;


• in water treated with ultraviolet radiation, toxic and mutagenic compounds that have a negative impact on the biocenosis of water bodies are not detected;


• unlike oxidative technologies, there are no negative effects in case of overdose. This makes it possible to significantly simplify the control over the disinfection process and not to carry out analyzes to determine the content of the residual concentration of the disinfectant in the water;


• disinfection time under UV irradiation is 1-10 seconds in flow mode, so there is no need to create contact containers;


• Recent advances in lighting and electrical engineering make it possible to ensure a high degree of reliability of UV complexes. Modern UV lamps and ballasts for them are mass-produced and have a high service life;


• disinfection by ultraviolet radiation is characterized by lower operating costs than chlorination and, especially, ozonation. This is due to the relatively low cost of electricity (3-5 times less than with ozonation); no need for expensive reagents: liquid chlorine, sodium or calcium hypochlorite, and no need for dechlorination reagents;


• there is no need to create warehouses for toxic chlorine-containing reagents that require compliance with special technical and environmental safety measures, which increases the reliability of water supply and sewerage systems in general;


• ultraviolet equipment is compact, requires minimal space, its implementation is possible in the existing technological processes of treatment facilities without stopping them, with minimal construction and installation work.

The ultraviolet radiation of the Sun and artificial sources, depending on the wavelength, is divided into three ranges:

• - region A - wavelength 400-320 nm (long-wave ultraviolet radiation UV-A);
• - area B - wavelength 320-275 nm (mid-wave ultraviolet radiation UV-B);
• - region C - wavelength 275-180 nm (short-wave ultraviolet radiation UV-C).

There are significant differences in the action of long, medium and short-wave radiation on cells, tissues and the body.

Area A (UV-A) long-wave radiation has a variety of biological effects, causes skin pigmentation and fluorescence of organic substances. UV-A rays have the highest penetrating power, which allows some atoms and molecules of the body to selectively absorb the energy of UV radiation and go into an unstable excited state. The subsequent transition to the initial state is accompanied by the release of light quanta (photons) capable of initiating various photochemical processes, primarily affecting DNA, RNA, and protein molecules.

Phototechnical processes cause reactions and changes on the part of various organs and systems, which form the basis of the physiological and therapeutic effect of UV rays. The shifts and effects occurring in an organism irradiated with UV rays (photoerythema, pigmentation, desensitization, bactericidal effect, etc.) have a clear spectral dependence (Fig. 1), which serves as the basis for the differentiated use of various sections of the UV spectrum.

Figure 1 - Spectral dependence of the most important biological effects of ultraviolet radiation

Irradiation with medium-wave UV rays causes photolysis of the protein with the formation of biologically active substances, and exposure to short-wave rays often leads to coagulation and denaturation of protein molecules. Under the influence of UV rays of the B and C ranges, especially in high doses, changes occur in nucleic acids, resulting in cell mutations.

At the same time, long-wavelength rays lead to the formation of a specific photoreactivation enzyme that promotes the recovery of nucleic acids.

1. The most widely used UV radiation is for therapeutic purposes.
2. UV rays are also used to sterilize and disinfect water, air, rooms, objects, etc.
3. Their use for preventive and cosmetic purposes is very common.
4. UV radiation is also used for diagnostic purposes, to determine the reactivity of the organism, in luminescent methods.

UV radiation is a vital factor, and its prolonged lack leads to the development of a kind of symptom complex, which has "light starvation" or "UV deficiency". Most often, it is manifested by the development of avitaminosis D, weakening of the protective immunobiological reactions of the body, exacerbation of chronic diseases, functional disorders of the nervous system, etc. workshops, engine rooms and in the Far North.

ultraviolet irradiation

Ultraviolet irradiation is produced by various artificial products with different wavelengths λ. The absorption of UV rays is accompanied by a number of primary photochemical and photophysical processes, which depend on their spectral composition and determine the physiological and therapeutic effect of the factor on the body.

Longwave ultraviolet(DUV) rays stimulate the proliferation of cells of the malpighian layer of the epidermis and the decarboxylation of tyrosine, followed by the formation of a spiny layer in the cells. Next comes the stimulation of the synthesis of ACTH and other hormones, etc. Various immunological changes are obtained.

DUV rays have a weaker biological effect than other UV rays, including the erythema-forming effect. To enhance the sensitivity of the skin to them, photosensitizers are used, most often compounds of the furocoumarin series (puvalen, beroxan, psoralen, amminofurin, etc.)

This property of long-wave radiation allows it to be used in the treatment of skin diseases. PUVA therapy method (salicylic alcohol is also used).

Thus, it is possible to highlight the main characteristics healing effects UV rays:

1. Therapeutic effects are

• - photosensitizing,
• - pigment-forming,
• - immunostimulating.

1. UV rays, like other areas of UV radiation, cause a change in the functional state of the central nervous system and its higher part of the cerebral cortex. Due to the reflex reaction, blood circulation improves, the sectoral activity of the digestive organs and the functional state of the kidneys increase.
2. UV rays affect metabolism, primarily mineral and nitrogen.
3. Local applications of photosensitizers are widely used for limited forms of psoriasis. Recently, UV-B has been successfully used as a sensitizer as it has a greater biological activity. The combined exposure of UV-A and UV-B is called selective exposure.
4. UV rays are used for both local and general exposures. The main indications for their use are:

• - skin diseases (psoriasis, eczema, vitiligo, seborrhea, etc.)
• - chronic inflammatory diseases of internal organs (especially respiratory organs)
• - diseases of the organs of support and movement of various ethnologies
• - burns, frostbite
• - sluggish wounds and ulcers, cosmetic purposes.

Contraindications

• - acute anti-inflammatory processes,
• - diseases of the liver and kidneys with a pronounced violation of their functions,
• - hyperthyroidism,
• - increased sensitivity to UV radiation.

medium wave ultraviolet(SUV) radiation has a pronounced and versatile biological effect.

When UV radiation quanta are absorbed in the skin, low-molecular products of protein photolysis and products of lipid peroxidation are formed. They cause changes in the ultrastructural organization of biological membranes, protein-lipid complexes, membrane enzymes and their most important physicochemical and functional properties.

Photodegradation products activate the system of mononuclear phagocytes and cause degranulation of mastocytes and basophils. As a result, biologically active substances (kinin, prostaglandin, heparin, leukotrienes, thromboxanes, etc.) and vasoactive mediators (acetylcholine, histamine) are released in the irradiated area and adjacent tissues, which significantly increase vascular permeability and tone, and also help to relax smooth muscles. . Due to humoral mechanisms, the number of functioning capillaries of the skin increases, the rate of local blood flow increases, which leads to the formation erythoma.

Repeated UV exposure can lead to the appearance of rapidly disappearing pigmentation, which enhances the barrier function of the skin, increases its cold sensitivity and resistance to the action of toxic substances and adverse factors.

Both the erythema response and other shifts induced by UV rays depend not only on the wavelength, but also on the dosage. In phototherapy, it is used in erythemal and suberythemal doses.

Exposure to suberythemal doses of UV rays promotes the formation of vitamin D in the skin, which, after its biotransformation in the liver and kidneys, is involved in the regulation of phosphorus-calcium metabolism in the body. UV irradiation contributes to the formation of not only vitamin D1, but also its isomer, ergocalcifemin (vitamin D2). The latter has an antirachitic effect, stimulates the aerobic and anaerobic pathways of cellular respiration. SUV rays in small doses also modulate the metabolism of other vitamins (A and C) and cause activation of metabolic processes in irradiated tissues. Under their influence, the adaptive-trophic function of the sympathetic nervous system is activated, the disturbed processes of various types of metabolism and cardiovascular activity are normalized.

Thus, UV radiation has a pronounced biological effect. Depending on the phase of irradiation, erythema on the skin and mucous membranes can be obtained or treated at a dose that does not cause it. The mechanism of the therapeutic action of erythemal and non-erythemal doses of SUF is different, therefore, the indications for the use of ultraviolet radiation will also be different.

Ultraviolet erythema appears at the site of UV-B irradiation after 2-8 hours and is associated with the death of epidermal cells. The products of protein photolysis enter the blood stream and cause vasodilation, skin edema, migration of leukocytes, irritation of numerous receptors, leading to a number of reflex reactions of the body.

In addition, the products of photolysis entering the blood stream have a humoral effect on individual organs, the nervous and endocrine systems of the body. The phenomena of aseptic inflammation gradually subside by the seventh day, leaving behind skin pigmentation at the site of irradiation.

The main therapeutic effects of UV radiation:

1. SUV-radiations are vitamin-forming, trophostimulating, immunomodulatory - these are suberythemal doses.
2. Anti-inflammatory, analgesic, desensitizing - this is an erythemal dose.
3. Bronchial diseases, asthma, hardening - this is an erythema-free dose.

Indications for topical use of UV-B (suberythemal and erythemal doses):

• - acute neuritis
• - acute meositis
• - pustular skin diseases (furucle, carbuncle, sycosis, etc.)
• - erysipelas
• - trophic ulcers
• - sluggish wounds
• - bedsores
• - inflammatory and post-traumatic diseases of the joints
• - rheumatoid arthritis
• - bronchial asthma
• - acute and chronic bronchitis
• - acute respiratory diseases
• - inflammation of the uterine appendages
• - chronic tonsillitis.

Erythema-free zones of ultraviolet radiation of spectrum B during general irradiation of the body eliminate the effects of D-hypovitaminosis associated with a lack of sunlight. It normalizes phosphorus-calcium metabolism, stimulates the function of the sympathetic-adrenal and pituitary-adrenal systems, increases the mechanical strength of bone tissue and stimulates the formation of callus, increases the resistance of the skin of the body and the body as a whole to harmful environmental factors. Allergic and exudative reactions decrease, mental and physical performance increases. Other disorders in the body caused by solar starvation are weakened.

Indications for general use of UV-B (erythema-free doses):

• - D-hypovitaminosis
• - metabolic disease
• - predisposition to pustular diseases
• - neurodermatitis
• - psoriasis
• - bone fractures and violation of the formation of callus
• - bronchial asthma
• - chronic diseases of the bronchial apparatus
• - hardening of the body.

Contraindications:

• - malignant neoplasms
• - tendency to bleed
• - systemic blood diseases
• - thyrotoxicosis
• - active tuberculosis
• - peptic ulcer of the stomach and duodenum in the acute stage
• - hypertension stage II and III
• - advanced atherosclerosis of the arteries of the brain and coronary arteries.

Shortwave ultraviolet radiation spectrum(UV) radiation.

UV radiation of the short-wave range is an active physical factor, since its quanta have the largest energy reserve. It can cause denaturation and photolysis of nucleic acids and proteins due to excessive absorption of the energy of its quanta by various molecules, primarily DNA and RNA.

When acting on microorganisms, on cells, this leads to inactivation of their genome and protein denaturation, which leads to their death.

When emitting KuV rays, a bactericidal effect occurs, since their direct hit on the protein is fatal for the cells of viruses, microorganisms and fungi.

After a short spasm, the UV rays cause dilation of the blood vessels, especially the subcapillary veins.

Indications for the use of UV radiation:

• - irradiation of wound surfaces
• - bedsores and almond-shaped niches after tonsillectomy with a bactericidal chain
• - sanitation of the nasopharynx in acute respiratory diseases
• - treatment of otitis externa
• - air disinfection in operating rooms, procedural rooms, inhalation rooms, intensive care units, patient wards, children's institutions and schools.

Skin and its function

Human skin makes up 18% of the human body weight and has a total area of ​​2m2. The skin consists of three anatomically and physiologically closely interconnected layers:

• - epidermis or cuticle
• - dermis (skin itself)
• - hypodermis (subcutaneous fat lining).

The epidermis is built from different in shape and structure, layered epithelial cells (epithermocytes). Moreover, each overlying cell comes from the underlying one, reflecting a certain phase of its life.

The layers of the epidermis are located in the following sequence (from bottom to top):

• - basal (D) or germinal;
• - a layer of spiny cells;
• - a layer of keratohyalin or granular cells;
• - epeidinovy ​​or brilliant;
• - horny.

In addition to epidermocytes, in the epidermis (in the basal layer) there are cells capable of producing melanin (melanocytes), Lagerhans, Greenstein cells, etc.

The dermis is located directly below the epidermis and is separated from it by the main membrane. The dermis is divided into papillary and reticular layers. It consists of collagen, elastic and reticulin (argyrophilic) fibers, between which the main substance is located.

In the dermis, in fact, in the skin is the papillary layer, richly supplied with blood and lymphatic vessels. There are also plexuses of nerve fibers, giving rise to numerous nerve endings in the epidermis and dermis. In the dermis, sweat and sebaceous glands, hair follicles are laid at various levels.

Subcutaneous fat is the deepest layer of the skin.

The functions of the skin are complex and varied. The skin performs barrier-protective, thermoregulatory, excretory, metabolic, receptor, etc.

The barrier-protective function, which is considered the most important function of the skin of humans and animals, is carried out through various mechanisms. Thus, the strong and elastic horny layer of the skin resists mechanical influences and reduces the harmful effects of chemicals. The stratum corneum, being a poor conductor, protects the deeper layers from drying out, cooling and the action of electric current.

Figure 2 - The structure of the skin

Sebum, a product of the secretion of sweat glands and flakes of exfoliating epithelium, form an emulsion film (protective mantle) on the surface of the skin, which plays an important role in protecting the skin from exposure to chemical, biological and physical agents.

The acid reaction of the water-lipid mantle and the surface layers of the skin, as well as the bactericidal properties of the skin secretion, are an important barrier mechanism for microorganisms.

The pigment melanin plays a role in protecting against light rays.

The electrophysiological barrier is the main obstacle to the penetration of substances into the depths of the skin, including during electrophoresis. It is located at the level of the basal layer of the epidermis and is an electrical layer with heterogeneous layers. The outer layer, due to the acid reaction, has a “+” charge, and the one facing inwards has a “-”. It should be borne in mind that, on the one hand, the barrier-protective function of the skin weakens the effect of physical factors on the body, and on the other hand, physical factors can stimulate the protective properties of the skin and thereby realize a therapeutic effect.

Physical thermoregulation body is also one of the most important physiological functions of the skin and is directly related to the mechanism of action of hydrotherapy factors. It is carried out by the skin by heat radiation in the form of infrared rays (44%), heat conduction (31%) and water evaporation from the skin surface (21%). It is important to note that the skin with its thermoregulatory mechanisms plays an important role in the acclimatization of the body.

Secret-excretory function skin is associated with the activity of sweat and sebaceous glands. It plays an important role in maintaining the homeostasis of the body, in the performance of skin barrier properties.

Respiratory and resorption function are closely interconnected. The respiratory function of the skin, consisting in the absorption of oxygen and the release of carbon dioxide, is of little importance in the overall balance of respiration for the body. However, respiration through the skin can increase significantly in conditions of high air temperature.

The resorption function of the skin, its permeability are of great importance not only in dermatology and toxicology. Its significance for physiotherapy is determined by the fact that the chemical component of the action of many therapeutic factors (medicinal, gas and mineral baths, mud therapy, etc.) depends on the penetration of their constituent ingredients through the skin.

exchange function skin has specific features. On the one hand, only its inherent metabolic processes occur in the skin (the formation of keratin, melanin, vitamin D, etc.), on the other hand, it takes an active part in the general metabolism in the body. Its role in fat, mineral, carbohydrate and vitamin metabolism is especially great.

The skin is also a site for the synthesis of biologically active substances (heparin, histamine, serotonin, etc.).

Receptor function skin provides its connection with the external environment. The skin performs this function in the form of numerous conditioned and unconditioned reflexes due to the presence in it of the various receptors mentioned above.

It is believed that there are 100-200 pain points per 1 cm2 of skin, 12-15 cold, 1-2 heat, 25 pressure points.

Relationship with internal organs closely related - skin changes affect the activity of internal organs, and violations of the internal organs are accompanied by shifts in the skin. This relationship is especially clearly manifested in internal diseases in the form of the so-called reflexogenic, or painful, Zakharin-Ged zones.

Zakharyin-Geda zone certain areas of the skin, in which, in diseases of the internal organs, reflected pain often appears, as well as pain and temperature hyperesthesia.

Figure 3 - Location of the Zakharyin-Ged zone

Such zones in diseases of the internal organs were also found in the head area. For example, pain in frontonasal region corresponds to the defeat of the tops of the lungs, stomach, liver, aortic mouth.

pain in the mid-eye region damage to the lungs, heart, ascending aorta.

pain in the frontotemporal region damage to the lungs and heart.

pain in the parietal region damage to the pylorus and upper intestine, etc.

Comfort zone the area of ​​temperature conditions of the external environment, causing a subjectively good heat sensation in a person without signs of cooling or overheating.

For a naked person 17.3 0С - 21.7 0С

For a dressed person 16.7 0С - 20.6 0С

Pulsed Ultraviolet Therapy

Research Institute of Energy Engineering, Moscow State Technical University. N. E. Bauman (Shashkovsky S. G. 2000) developed a portable device "Melitta 01" for local irradiation of the affected surfaces of skin coatings, mucous membranes with highly efficient pulsed continuous spectrum ultraviolet radiation in the range of 230-380 nm.

The operating mode of this device is pulse-periodic with a frequency of 1 Hz. The device provides automatic generation of 1, 4, 8, 16, 32 pulses. Output pulsed power density at a distance of 5 cm from the burner 25 W/cm2

Indications:

• - purulent-inflammatory diseases of the skin and subcutaneous tissue (furuncle, carbuncle, hydradenitis) in the initial period of hydration and after surgical opening of the purulent cavity;
• - extensive purulent wounds, wounds after necrectomy, wounds before and after autodermoplasty;
• - granulating wounds after thermal, chemical, radiation burns;
• - trophic ulcers and sluggish wounds;
• - erysipelas;
• - herpetic inflammation of the skin and mucous membranes;
• - irradiation of wounds before and after primary surgical treatment in order to prevent the development of purulent complications;
• - disinfection of indoor air, car interior, bus and ambulance.

Pulse magnetic therapy with a rotating field and changing the frequency of repetition of impulses automatically.

The therapeutic effect is based on well-known physical laws. An electric charge moving through a blood vessel in a magnetic field is affected by the Lorentz force perpendicular to the charge velocity vector, constant in a constant and alternating sign in an alternating, rotating magnetic field. This phenomenon is realized at all levels of the organism (atomic, molecular, subcellular, cellular, tissue).

The action of low-intensity pulsed magnetic therapy has an active effect on deeply located muscle, nervous, bone tissue, internal organs, improving microcirculation, stimulating metabolic processes and regeneration. Electric currents of high density, induced by a pulsed magnetic field, activate myelinated thick nerve fibers, as a result of which afferent impulses from the pain focus are blocked by the spinal mechanism of the "gate block". The pain syndrome is weakened or eliminated completely already during the procedure or after the first procedures. In terms of the severity of the analgesic effect, pulsed magnetic therapy is much superior to other types of magnetic therapy.

Thanks to pulsed rotating magnetic fields, it becomes possible to indicate in the depths of tissues without damage to electric fields and currents of significant intensity. This allows you to get a pronounced therapeutic decongestant, analgesic, anti-inflammatory, stimulating regeneration processes, biostimulating effects of action, which are several times more pronounced than the therapeutic effects obtained from all known low-frequency magnetic therapy devices.

Pulsed magnetic therapy devices are a modern and effective means of treating traumatic injuries, inflammatory, degenerative-dystrophic diseases of the nervous and musculoskeletal systems.

Therapeutic effects of pulsed magnetic therapy: analgesic, decongestant, anti-inflammatory, vasoactive, stimulating regeneration processes in damaged tissues, neurostimulating, myostimulating.

Indications:

• - diseases and traumatic injuries of the central nervous system (ischemic stroke of the brain, transient cerebrovascular accident, consequences of a craniocerebral injury with movement disorders, closed spinal cord injuries with movement disorders, cerebral palsy, functional hysterical paralysis),
• - traumatic injuries of the musculoskeletal system (bruises of soft tissues, joints, bones, sprains, closed fractures of bones and joints during immobilization, in the stage of reparative regeneration, open fractures of bones, joints, soft tissue injuries during immobilization, in the stage of reparative regeneration, malnutrition , muscle atrophy as a result of hypodynamia caused by traumatic injuries of the musculoskeletal system),
• - inflammatory degenerative-dystrophic injuries of the musculoskeletal system (deforming osteoarthritis of the joints with synovitis and without synovitis, widespread osteochondrosis, deforming spondylosis of the spine with symptoms of secondary radicular syndrome, cervical sciatica with symptoms of humeroscapular periatritis, thoracic sciatica, sciatica, ankylosing spondyloatritis, scoliosis in children),
• - surgical inflammatory diseases (postoperative period after surgical interventions on the musculoskeletal system, skin and subcutaneous tissue, sluggish wounds, trophic ulcers, boils, carbuncles, phlegmon after surgery, mastitis),
• - diseases of the bronchopulmonary system (bronchial asthma of mild and moderate severity, chronic bronchitis),
• - diseases of the digestive system (hypomotor-evacuation disorders of the stomach after the stomach and vagotomy, hypomotor dysfunction of the colon, stomach and gallbladder, chronic hepatitis with moderate liver dysfunction, chronic pancreatitis with secretory insufficiency),
• - diseases of the cardiovascular system (occlusive lesions of peripheral arteries of atherosclerotic origin),
• - urological diseases (stone in the ureter, condition after lithotripsy, atony of the bladder, weakness of the sphinker and detrusor, prostatitis),
• - gynecological diseases (inflammatory diseases of the uterus and appendages, diseases caused by ovarian hypofunction),
• - chronic prostatitis and sexual disorders in men,
• - dental diseases (periodontal disease, filling pain).

Contraindications:

• - marked hypotension
• - systemic blood diseases,
• - tendency to bleed
• - thrombophlebitis,
• - thromboembolic disease, bone fractures before immobilization,
• - pregnancy,
• - thyrotoxicosis and nodular goiter,
• - abscess, phlegmon (before opening and draining the cavities),
• - malignant neoplasms,
• - feverish state
• - cholelithiasis,
• - epilepsy.

A warning:

Pulsed magnetic therapy cannot be used in the presence of an implanted pacemaker, since induced electrical potentials can disrupt its operation; with various metal objects freely lying in the tissues of the body (for example, fragments in case of injuries), if they are at a distance of less than 5 cm from the inductors, since when passing magnetic field pulses, objects made of electrically conductive materials (steel, copper, etc.) can move and cause damage to surrounding tissues. It is not allowed to influence the area of ​​the brain, heart and eyes.

Of great interest is the creation of low-intensity pulsed magnetic devices (20-150 mT) with a pulse repetition rate approximately coinciding with the frequency of the organs' own biopotentials (2-4-6-8-10-12 Hz). This would make it possible to exert a bioresonance effect on the internal organs (liver, pancreas, stomach, lungs) with a pulsed magnetic field and positively influence their function. It is already known that UTI has a positive effect at a frequency of 8-10 Hz on liver function in patients with toxic (alcoholic) hepatitis.

The concept of ultraviolet rays is first encountered by a 13th century Indian philosopher in his work. The atmosphere of the area he described Bhootakasha contained violet rays that cannot be seen with the naked eye.

Shortly after infrared radiation was discovered, the German physicist Johann Wilhelm Ritter began looking for radiation at the opposite end of the spectrum, with a wavelength shorter than that of violet. In 1801, he discovered that silver chloride, which decomposes under the influence of light, is faster decomposes under the action of invisible radiation outside the violet region of the spectrum. White silver chloride darkens in the light for several minutes. Different parts of the spectrum have different effects on the darkening rate. This happens most quickly before the violet region of the spectrum. It was then agreed by many scientists, including Ritter, that light consisted of three separate components: an oxidizing or thermal (infrared) component, an illuminating component (visible light), and a reducing (ultraviolet) component. At that time, ultraviolet radiation was also called actinic radiation. The ideas about the unity of the three different parts of the spectrum were first voiced only in 1842 in the works of Alexander Becquerel, Macedonio Melloni and others.

Subtypes

Degradation of polymers and dyes

Scope of application

Black light

Chemical analysis

UV spectrometry

UV spectrophotometry is based on irradiating a substance with monochromatic UV radiation, the wavelength of which changes with time. The substance absorbs UV radiation with different wavelengths to varying degrees. The graph, on the y-axis of which the amount of transmitted or reflected radiation is plotted, and on the abscissa - the wavelength, forms a spectrum. The spectra are unique for each substance; this is the basis for the identification of individual substances in a mixture, as well as their quantitative measurement.

Mineral analysis

Many minerals contain substances that, when illuminated with ultraviolet radiation, begin to emit visible light. Each impurity glows in its own way, which makes it possible to determine the composition of a given mineral by the nature of the glow. A. A. Malakhov in his book “Interesting about Geology” (M., “Molodaya Gvardiya”, 1969. 240 s) talks about this as follows: “The unusual glow of minerals is caused by cathode, ultraviolet, and x-rays. In the world of dead stone, those minerals light up and shine most brightly, which, having fallen into the zone of ultraviolet light, tell about the smallest impurities of uranium or manganese included in the composition of the rock. Many other minerals that do not contain any impurities also flash with a strange "unearthly" color. I spent the whole day in the laboratory, where I observed the luminescent glow of minerals. Ordinary colorless calcite colored miraculously under the influence of various light sources. Cathode rays made the crystal ruby ​​red, in ultraviolet it lit up crimson red tones. Two minerals - fluorite and zircon - did not differ in x-rays. Both were green. But as soon as the cathode light was turned on, the fluorite turned purple, and the zircon turned lemon yellow.” (p. 11).

Qualitative chromatographic analysis

Chromatograms obtained by TLC are often viewed in ultraviolet light, which makes it possible to identify a number of organic substances by the color of the glow and the retention index.

Catching insects

Ultraviolet radiation is often used when catching insects in the light (often in combination with lamps emitting in the visible part of the spectrum). This is due to the fact that in most insects the visible range is shifted, compared to human vision, to the short-wavelength part of the spectrum: insects do not see what a person perceives as red, but they see soft ultraviolet light.

Faux tan and "Mountain sun"

At certain dosages, artificial tanning can improve the condition and appearance of human skin, promotes the formation of vitamin D. At present, photariums are popular, which in everyday life are often called solariums.

Ultraviolet in restoration

One of the main tools of experts is ultraviolet, x-ray and infrared radiation. Ultraviolet rays allow you to determine the aging of the varnish film - a fresher varnish in the ultraviolet looks darker. In the light of a large laboratory ultraviolet lamp, restored areas and handicraft signatures appear as darker spots. X-rays are delayed by the heaviest elements. In the human body, this is bone tissue, and in the picture it is white. The basis of whitewash in most cases is lead, in the 19th century zinc began to be used, and in the 20th century titanium. These are all heavy metals. Ultimately, on the film we get the image of the bleach underpainting. Underpainting is an artist's individual "handwriting", an element of his own unique technique. For the analysis of underpainting, bases of radiographs of paintings by great masters are used. Also, these pictures are used to recognize the authenticity of the picture.

Notes

1. ISO 21348 Process for Determining Solar Irradiances. Archived from the original on June 23, 2012.
2. Bobukh, Evgeny On the vision of animals. Archived from the original on November 7, 2012. Retrieved November 6, 2012.
3. Soviet Encyclopedia
4. V. K. Popov // UFN. - 1985. - T. 147. - S. 587-604.
5. A. K. Shuaibov, V. S. Shevera Ultraviolet nitrogen laser at 337.1 nm in the mode of frequent repetitions // Ukrainian Physics Journal. - 1977. - T. 22. - No. 1. - S. 157-158.
6. A. G. Molchanov

Ultraviolet radiation is a form of optical radiation invisible to the human eye, characterized by a shorter length and higher energy of photons compared to light. Ultraviolet rays cover the spectrum interval between visible and X-ray radiation, in the wavelength range of 400-10 nm. In this case, the radiation region in the range of 200-10 nm is called far or vacuum, and the region in the range of 400-200 nm is called near.

Sources of UV radiation

1 Natural sources (stars, sun, etc.)

Only the long-wavelength part of the ultraviolet radiation of space objects (290-400nm) is able to reach the Earth's surface. At the same time, short-wave radiation is completely absorbed by oxygen and other substances in the atmosphere at a height of 30-200 km from the earth's surface. UV radiation from stars in the wavelength range of 90-20 nm is almost completely absorbed.

2. Artificial sources

The radiation of solids heated to a temperature of 3 thousand kelvins includes a certain amount of UV radiation, the intensity of which increases markedly with increasing temperature.

A powerful source of UV radiation is gas-discharge plasma.

In various industries (food, chemical, and other industries) and medicine, gas-discharge, xenon, mercury-quartz, and other lamps are used, the bulbs of which are made of transparent materials—usually quartz. Significant UV radiation is emitted by electrons in the accelerator and special lasers in the nickel-like ion.

Basic properties of ultraviolet radiation

The practical use of ultraviolet is due to its main properties:

- significant chemical activity (contributes to the acceleration of chemical, biological processes);

- bactericidal effect;

- the ability to cause the luminescence of substances - a glow with different colors of the emitted light.

The study of emission / absorption / reflection spectra in the UV range using modern equipment makes it possible to establish the electronic structure of atoms, molecules, ions.

The UV spectra of the Sun, stars, and various nebulae make it possible to obtain reliable information about the processes occurring in these objects.

Also, ultraviolet is able to break and change chemical bonds in molecules, as a result, various reactions can occur (reduction, oxidation, polymerization, etc.), which serves as the basis for such a science as photochemistry.

UV radiation is capable of destroying bacteria and microorganisms. Thus, ultraviolet lamps are widely used for disinfection in crowded places (medical institutions, kindergartens, subways, railway stations, etc.).

Certain doses of UV radiation contribute to the formation of vitamin D, serotonin and other substances on the surface of human skin that affect the tone and activity of the body. Excessive exposure to ultraviolet radiation leads to burns, accelerates the aging process of the skin.

Ultraviolet radiation is also actively used in the cultural and entertainment field - to create a series of unique lighting effects at discos, stages of bars, theaters, etc.