Where is the ultraviolet. Properties of ultraviolet radiation and its effect on the human body

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

Exposure to medium-wavelength UV rays causes protein photolysis with the formation of biologically active substances, and exposure to short-wavelength 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 is capable of causing denaturation and photolysis of nucleic acids and proteins due to the 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 the 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 acidic reaction of the water-lipid mantle and 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 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.

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 properties of ultraviolet radiation are determined by many parameters. Ultraviolet radiation is called invisible electromagnetic radiation, which occupies a certain spectral region between X-ray and visible radiation within the respective wavelengths. The wavelength of ultraviolet radiation is 400 - 100 nm and has weak biological effects.

The higher the biological activity of the waves of this radiation, the weaker the effect, respectively, the lower the wavelength, the stronger the biological activity. Waves with a length of 280 - 200 nm have the strongest activity, which have bactericidal effects and actively affect body tissues.

The frequency of ultraviolet radiation is closely related to wavelengths, so the higher the wavelength, the lower the frequency of the radiation. The range of ultraviolet radiation reaching the Earth's surface is 400 - 280 nm, and shorter waves emanating from the Sun are absorbed even in the stratosphere with the help of ozone layer.

The area of ​​UV radiation is conditionally divided into:

• Near - from 400 to 200 nm
• Far - from 380 to 200 nm
• Vacuum - from 200 to 10 nm

The spectrum of ultraviolet radiation depends on the nature of the origin of this radiation and can be:

• Linear (radiation of atoms, light molecules and ions)
• Continuous (deceleration and recombination of electrons)
• Consisting of bands (radiation of heavy molecules)

Properties of UV radiation

The properties of ultraviolet radiation are chemical activity, penetrating power, invisibility, destruction of microorganisms, beneficial effects on the human body (in small doses) and negative effects on humans (in large doses). Properties of ultraviolet radiation in optical area have significant differences from the optical properties of the ultraviolet of the visible region. The most characteristic feature is the increase in the special absorption coefficient, which leads to a decrease in the transparency of many bodies that have transparency in visible area.

The reflection coefficient of various bodies and materials decreases taking into account the decrease in the wavelength of the radiation itself. The physics of ultraviolet radiation corresponds to modern ideas and ceases to be an independent dynamics at high energies, and is also combined into one theory with all gauge fields.

Do you know what is different for different intensities of such radiation? Read detailed information about beneficial and harmful doses of UV radiation in one of our articles.

We also have information about use in the garden. Many summer residents are already using solar panels in their homes. Try it by reading our material.

History of the discovery of ultraviolet radiation

Ultraviolet radiation, whose discovery history dates back to 1801, was announced only in 1842. This phenomenon was discovered by the German physicist Johann Wilhelm Ritter and was called " actinic radiation". This radiation was part of the individual components of light, and played the role of a reducing element.

The very concept of ultraviolet rays was first encountered in history in the 13th century, in the work of the scientist Sri Madhacharaya, who described the atmosphere of the Bhutakashi area containing violet rays invisible to human eyes.

In the course of experiments in 1801, a group of scientists found that light has several separate components: oxidative, thermal (infrared), illuminating (visible light) and reducing (ultraviolet).

UV - radiation is a continuously acting factor of the environment and has a strong impact on various physiological processes that occur in organisms.

According to scientists, it was it that played the main role in the course of evolutionary processes on Earth. Due to this factor, an abiogenic synthesis of organic terrestrial compounds occurred, which influenced the increase in the diversity of life forms.

It turned out that all living beings, in the course of evolution, have adapted to use the energy of all parts of the spectrum of solar energy. The visible part of the solar range is for photosynthesis, the infrared for heat. UV components are used as photochemical synthesis vitamin D, which plays an important role in the exchange of phosphorus and calcium in the body of living beings and humans.

The ultraviolet range is located from visible light from the short-wave side, and the rays of the near region are perceived by a person as the appearance of a tan on the skin. Short waves cause a destructive effect on biological molecules.

The ultraviolet radiation of the sun has the biological effectiveness of three spectral regions, which differ significantly from each other and have corresponding ranges that affect living organisms in different ways.

This radiation is taken for therapeutic and prophylactic purposes in certain dosages. For such medical procedures, special artificial radiation sources are used, the radiation spectrum of which consists of shorter rays, which has a more intense effect on biological tissues.

Harm from ultraviolet radiation brings a strong effect of this radiation source on the body and can cause damage mucous membranes and various skin dermatitis. Basically, damage from ultraviolet radiation is observed in workers in various fields of activity who are in contact with artificial sources of these waves.

Measurement of ultraviolet radiation is carried out by multichannel radiometers and continuous wave spectroradiometers, which are based on the use of vacuum photodiodes and photoids with a limited wavelength range.

Properties of ultraviolet radiation photo

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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 “Entertaining 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 improves 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

I remember disinfection with UV lamps from childhood - in the kindergarten, sanatorium and even in the summer camp there were somewhat frightening structures that glowed with a beautiful purple light in the dark and from which the educators drove us away. So what exactly is ultraviolet radiation and why does a person need it?

Perhaps the first question to be answered is what ultraviolet rays are and how they work. This is usually referred to as electromagnetic radiation, which is in the range between visible and X-ray radiation. Ultraviolet is characterized by a wavelength from 10 to 400 nanometers.
It was discovered back in the 19th century, and this happened thanks to the discovery of infrared radiation. Having discovered the IR spectrum, in 1801 I.V. Ritter drew attention to the opposite end of the light spectrum during experiments with silver chloride. And then several scientists at once came to the conclusion about the heterogeneity of the ultraviolet.

Today it is divided into three groups:

• UV-A radiation - near ultraviolet;
• UV-B - medium;
• UV-C - far.

This division is largely due to the impact of rays on a person. The natural and main source of ultraviolet radiation on Earth is the Sun. In fact, it is from this radiation that we are saved by sunscreens. At the same time, far ultraviolet is completely absorbed by the Earth's atmosphere, and UV-A just reaches the surface, causing a pleasant tan. And on average, 10% of UV-B provokes those same sunburns, and can also lead to the formation of mutations and skin diseases.

Artificial sources of ultraviolet are created and used in medicine, agriculture, cosmetology and various sanitary institutions. Generation of ultraviolet radiation is possible in several ways: by temperature (incandescent lamps), by the movement of gases (gas lamps) or metal vapors (mercury lamps). At the same time, the power of such sources varies from a few watts, usually small mobile radiators, to a kilowatt. The latter are mounted in volumetric stationary installations. The areas of application of UV rays are due to their properties: the ability to accelerate chemical and biological processes, the bactericidal effect and the luminescence of certain substances.

Ultraviolet is widely used to solve a variety of problems. In cosmetology, the use of artificial UV radiation is used primarily for tanning. Solariums produce rather mild UV-A according to the introduced standards, and the share of UV-B in tanning lamps is no more than 5%. Modern psychologists recommend solariums for the treatment of "winter depression", which is mainly caused by vitamin D deficiency, as it is formed under the influence of UV rays. Also, UV lamps are used in manicure, since it is in this spectrum that especially resistant gel polishes, shellac and the like dry out.

Ultraviolet lamps are used to create photographs in non-standard situations, for example, to capture space objects that are invisible with a conventional telescope.

Ultraviolet is widely used in expert activities. With its help, the authenticity of the paintings is checked, since fresher paints and varnishes in such rays look darker, which means that the real age of the work can be established. Forensics also use UV rays to detect traces of blood on objects. In addition, ultraviolet light is widely used to develop hidden seals, security features and document authentication threads, as well as in the lighting design of shows, restaurant signs or decorations.

In healthcare facilities, ultraviolet lamps are used to sterilize surgical instruments. In addition, air disinfection using UV rays is still widespread. There are several types of such equipment.

So called high and low pressure mercury lamps, as well as xenon flash lamps. The bulb of such a lamp is made of quartz glass. The main advantage of germicidal lamps is their long service life and instantaneous ability to work. Approximately 60% of their rays are in the bactericidal spectrum. Mercury lamps are quite dangerous in operation; in case of accidental damage to the housing, thorough cleaning and demercurization of the room is necessary. Xenon lamps are less dangerous if damaged and have a higher bactericidal activity. Also bactericidal lamps are divided into ozone and ozone-free. The former are characterized by the presence in their spectrum of a wave with a length of 185 nanometers, which interacts with oxygen in the air and turns it into ozone. High concentrations of ozone are dangerous for humans, and the use of such lamps is strictly limited in time and is recommended only in a ventilated area. All this led to the creation of ozone-free lamps, the bulb of which is coated with a special coating that does not transmit a wave of 185 nm to the outside.

Regardless of the type, bactericidal lamps have common drawbacks: they work in complex and expensive equipment, the average life of the emitter is 1.5 years, and the lamps themselves, after burnout, must be stored packed in a separate room and disposed of in a special way in accordance with current regulations.

Consist of a lamp, reflectors and other auxiliary elements. Such devices are of two types - open and closed, depending on whether UV rays pass out or not. Open emit ultraviolet, enhanced by reflectors, into the space around, capturing almost the entire room at once, if installed on the ceiling or wall. It is strictly forbidden to treat the premises with such an irradiator in the presence of people.
Closed irradiators work on the principle of a recirculator, inside which a lamp is installed, and the fan draws air into the device and releases the already irradiated air to the outside. They are placed on the walls at a height of at least 2 m from the floor. They can be used in the presence of people, but long-term exposure is not recommended by the manufacturer, as part of the UV rays can pass out.
Among the shortcomings of such devices, one can note immunity to mold spores, as well as all the difficulties of recycling lamps and strict regulations for use, depending on the type of emitter.

Germicidal installations

A group of irradiators combined into one device used in one room is called a bactericidal installation. Usually they are quite large and are characterized by high power consumption. Air treatment with bactericidal installations is carried out strictly in the absence of people in the room and is monitored according to the Commissioning Certificate and the Registration and Control Log. It is used only in medical and hygienic institutions for disinfection of both air and water.

Disadvantages of ultraviolet air disinfection

In addition to those already listed, the use of UV emitters has other disadvantages. First of all, ultraviolet itself is dangerous for the human body, it can not only cause skin burns, but also affect the functioning of the cardiovascular system, it is dangerous for the retina. In addition, it can cause the appearance of ozone, and with it the unpleasant symptoms inherent in this gas: irritation of the respiratory tract, stimulation of atherosclerosis, exacerbation of allergies.

The effectiveness of UV lamps is quite controversial: the inactivation of pathogens in the air by permitted doses of ultraviolet radiation occurs only when these pests are static. If microorganisms move, interact with dust and air, then the required radiation dose increases by 4 times, which a conventional UV lamp cannot create. Therefore, the efficiency of the irradiator is calculated separately, taking into account all the parameters, and it is extremely difficult to choose the right ones for influencing all types of microorganisms at once.

Penetration of UV rays is relatively shallow, and even if the immobile viruses are under a layer of dust, the upper layers protect the lower ones by reflecting ultraviolet from themselves. So, after cleaning, disinfection must be carried out again.
UV irradiators cannot filter the air, they only fight microorganisms, keeping all mechanical pollutants and allergens in their original form.

Light therapy is actively used in medical practice for the treatment of various diseases. It includes the use of visible light, laser, infrared, and ultraviolet rays (UVR). The most commonly prescribed UFO-physiotherapy.

It is used for the treatment of ENT pathologies, diseases of the musculoskeletal system, immunodeficiencies, bronchial asthma and other diseases. Ultraviolet irradiation is also used for a bacteriostatic effect in infectious diseases, for indoor air treatment.

General concept of ultraviolet irradiation, types of devices, mechanism of action, indications

Ultraviolet irradiation (UVR) is a physiotherapeutic procedure based on the effect of ultraviolet rays on tissues and organs. The effect on the body may differ when using different wavelengths.

UV rays have different wavelengths:

• Long wavelength (DUV) (400–320 nm).
• Medium wave (SUV) (320–280 nm).
• Shortwave (CUV) (280–180 nm).

For physiotherapy, special devices are used. They generate ultraviolet rays of different lengths.

UV-devices for physiotherapy:

• Integral. Generate the entire spectrum of UV radiation.
• Selective. They produce one type of ultraviolet radiation: short-wave, a combination of short-wave and medium-wave spectra.

In physiotherapy, ultraviolet irradiation is prescribed for the prevention and treatment of various diseases. The mechanism of exposure to ultraviolet radiation is as follows: metabolic processes are activated, the transmission of impulses along nerve fibers improves. When UV rays hit the skin, the patient develops erythema. It looks like redness of the skin. The invisible period of erythema formation is 3-12 hours. The resulting erythematous formation remains on the skin for several more days, it has clear boundaries.

The long-wave spectrum does not cause very pronounced erythema. Medium-wave rays are able to reduce the number of free radicals, stimulate the synthesis of ATP molecules. Short UV rays very quickly provoke an erythematous rash.

Small doses of medium and long UV waves are not capable of causing erythema. They are needed for a general effect on the body.

Benefits of small doses of UVR:

• Enhances the formation of red blood cells and other blood cells.
• Increases the function of the adrenal glands, the sympathetic system.
• Reduces the formation of fat cells.
• Improves the performance of the naming system.
• Stimulates immune responses.
• Normalizes blood glucose levels.
• Reduces the amount of blood cholesterol.
• Regulates the excretion and absorption of phosphorus and calcium.
• Improves heart and lung function.

Local radiation helps to stimulate immune responses in the area where the rays hit, increases blood flow and lymph outflow.

Radiation doses that do not cause redness have the following properties: increase regenerative function, enhance tissue nutrition, stimulate the appearance of melanin in the skin, increase immunity, stimulate the formation of vitamin D. Higher doses that cause erythema (often CUF) are able to kill bacterial agents, reduce the intensity of pain, reduce inflammation on the mucous membranes and skin.

Indications for physiotherapy

Contraindications to radiation are:

• tumor process.
• Hyperthermia.
• Infectious diseases.
• Hyperproduction of thyroid hormones.
• Lupus erythematosus.
• Hepatic and renal dysfunction.

The method of conducting ultraviolet irradiation

Before treatment, the physiotherapist must decide on the type of rays. A prerequisite is the calculation of radiation exposure to the patient. The load is measured in biodoses. The calculation of the number of biodoses is carried out according to the Gorbachev-Dalfeld method. It is based on the speed of formation of reddening of the skin. One biodose is capable of causing minimal redness from a distance of 50 cm. This dosage is erythematous.

Erythemal doses are divided into:

• small (one or two biodoses);
• medium (three to four biodoses);
• high (five to eight biodoses).

If the radiation dose is more than eight biodoses, then it is called hypererythemic. Irradiation is divided into general and local. The general may be intended for one person or a group of patients. Such radiation is produced by integral devices or sources of long waves.

Children need to be irradiated with general UV very carefully. For a child and a student, an incomplete biodose is used. Start with the smallest dosage.

With a general exposure to UV rays of newborns and very weak babies, at the initial stage, 1/10–1/8 of the biodose is affected. Schoolchildren and preschoolers use 1/4 of the biodose. Over time, the load is increased to 1 1/2-1 3/4 biodoses. This dosage remains for the entire stage of therapy. Sessions are held every other day. 10 sessions are enough for treatment.

During the procedure, the patient must be undressed, put on the couch. The device is placed at a distance of 50 cm from the surface of the patient's body. The lamp should be covered with a cloth or blanket along with the patient. This ensures that the maximum dose of radiation is obtained. If you do not cover with a blanket, then part of the rays emanating from the source is scattered. The effectiveness of therapy in this case will be low.

Local exposure to UV radiation is carried out by devices of a mixed type, as well as emitting short waves of the UV spectrum. During local physiotherapy, it is possible to influence reflexogenic zones, irradiate with fractions, fields, near the injury site.

Local irradiation often causes reddening of the skin, which has a healing effect. In order to properly stimulate the formation of erythema, after its appearance, the following sessions begin after its blanching. The intervals between physiotherapy are 1-3 days. The dosage in subsequent sessions is increased by a third or more.

For intact skin, 5-6 physiotherapy procedures are enough. If there are purulent lesions, bedsores on the skin, then it is necessary to irradiate up to 12 sessions. For mucous membranes, course therapy is 10-12 sessions.

For children, local use of UVR is permitted from birth. It is limited in area. In a newborn child, the impact area is 50 cm2 or more, for schoolchildren it is not more than 300 cm2. The dosage for erythemotherapy is 0.5-1 biodose.

In acute respiratory diseases, the nasopharyngeal mucosa is treated with UV. For this, special tubes are used. The session lasts 1 minute (adults), half a minute (children). Course therapy is 7 days.

The chest is irradiated in the fields. The duration of the procedure is 3-5 minutes. The fields are processed separately on different days. Sessions take place every day. The multiplicity of field irradiation per course is 2-3 times, oilcloth or perforated fabric is used to isolate it.

With a runny nose in the acute period, ultraviolet exposure is carried out on the legs from the side of the sole. The source is installed at a distance of 10 cm. The course of treatment is up to 4 days. Irradiation is also done with a tube in the nose and throat. The first session lasts 30 seconds. In the future, therapy is extended to 3 minutes. Course therapy is 6 sessions.

With otitis media, ultraviolet exposure is carried out on the site of the ear canal. The session lasts 3 minutes. The therapy includes 6 physiotherapy procedures. In patients with pharyngitis, laryngitis, tracheitis, irradiation is performed along the anterior upper part of the chest. The number of procedures per course is up to 6.

With tracheitis, pharyngitis, tonsillitis, irradiation of the back wall of the pharynx (throat) can be done using tubes. During the session, the patient should say the sound "a". The duration of the physiotherapy is 1-5 minutes. Treatment is carried out every 2 days. Course therapy is 6 sessions.

Pustular skin lesions are treated by UVI after treatment of the wound surface. The source of ultraviolet light is set at a distance of 10 cm. The duration of the session is 2-3 minutes. Treatment continues for 3 days.

Furuncles and abscesses are irradiated after opening the formation. The treatment is carried out at a distance of 10 cm to the surface of the body. The duration of one physiotherapy is 3 minutes. Course therapy 10 sessions.

UV treatment at home

Ultraviolet irradiation is permissible to carry out at home. To do this, you can purchase a UFO device at any medical equipment store. For the implementation of UV-physiotherapy at home, the apparatus "Sun" (OUFb-04) was developed. It is intended for local action on mucous membranes and skin.

For general irradiation, you can purchase a mercury-quartz lamp "Sun". It will replace part of the missing ultraviolet light in winter, disinfect the air. There are also home irradiators for shoes, water.

The device "Sun" for local use is equipped with a tube for the nose, throat, treatment of other parts of the body. The device is small. Before purchasing, you should make sure that the device is in good condition, that there are certificates and quality assurance. To clarify the rules for using the device, you must read the instructions, or contact your doctor.

Conclusion

Ultraviolet radiation is often used in medicine for the treatment of various diseases. In addition to treatment, UV devices can be used for disinfection of premises. They are used in hospitals and at home. With the correct use of lamps, irradiation does not cause harm, and the effectiveness of treatment is quite high.