Ultraviolet rays have the highest biological activity. Under natural conditions, the sun is a powerful source of ultraviolet rays. However, only its long-wavelength part reaches the earth's surface. Shorter wavelength radiation is absorbed by the atmosphere already at a height of 30-50 km from the earth's surface.

The highest intensity of the ultraviolet radiation flux is observed shortly before noon with a maximum in the spring months.

As already mentioned, ultraviolet rays have significant photochemical activity, which is widely used in practice. Ultraviolet irradiation is used in the synthesis of a number of substances, the bleaching of fabrics, the manufacture of patent leather, the blueprinting of blueprints, the production of vitamin D, and other production processes.

An important property of ultraviolet rays is their ability to cause luminescence.

In some processes, exposure to working ultraviolet rays takes place, for example, electric welding with a voltaic arc, oxyfuel cutting and welding, the production of radio lamps and mercury rectifiers, casting and smelting of metals and certain minerals, blueprinting, water sterilization, etc. Medical and technical personnel servicing mercury-quartz lamps.

Ultraviolet rays have the ability to change the chemical structure of tissues and cells.

UV wavelength

The biological activity of ultraviolet rays of different wavelengths is not the same. Ultraviolet rays with a wavelength of 400 to 315 mμ. have a relatively weak biological effect. Rays with a shorter wavelength are more biologically active. Ultraviolet rays with a length of 315-280 mμ have a strong skin and anti-rachitic effect. Radiation with a wavelength of 280-200 mμ has a particularly high activity. (bactericidal action, the ability to actively affect tissue proteins and lipoids, as well as cause hemolysis).

Under production conditions, exposure to ultraviolet rays with a wavelength of 36 to 220 mμ ., i.e., with significant biological activity, takes place.

Unlike heat rays, the main property of which is the development of hyperemia in areas exposed to radiation, the effect of ultraviolet rays on the body seems to be much more complex.

Ultraviolet rays penetrate the skin relatively little and their biological effect is associated with the development of many neurohumoral processes that determine the complex nature of their influence on the body.

Ultraviolet erythema

Depending on the intensity of the light source and the content of infrared or ultraviolet rays in its spectrum, changes in the skin will not be the same.

Exposure to ultraviolet rays on the skin causes a characteristic reaction from the skin vessels - ultraviolet erythema. Ultraviolet erythema is significantly different from thermal erythema caused by infrared radiation.

Usually, when using infrared rays, pronounced changes in the skin are not observed, since the resulting burning sensation and pain prevent prolonged exposure to these rays. Erythema, which develops as a result of the action of infrared rays, occurs immediately after irradiation, is unstable, does not last long (30-60 minutes) and is mainly of a nested nature. After prolonged exposure to infrared rays, brown pigmentation of a spotted appearance appears.

Ultraviolet erythema appears after irradiation following a certain latent period. This period varies in different people from 2 to 10 hours. The duration of the latent period of ultraviolet erythema is in a known dependence on the wavelength: erythema from long-wave ultraviolet rays appears later and lasts longer than from short-wave ones.

Erythema caused by ultraviolet rays has a bright red color with sharp borders, exactly corresponding to the site of exposure. The skin becomes somewhat swollen and painful. The greatest development of erythema reaches 6-12 hours after the onset, lasts for 3-5 days and gradually turns pale, acquiring a brown tint, and there is a uniform and intense darkening of the skin due to the formation of pigment in it. In some cases, during the period of disappearance of erythema, slight peeling is observed.

The degree of development of erythema depends on the dose of ultraviolet rays and individual sensitivity. Ceteris paribus, the greater the dose of ultraviolet rays, the more intense the inflammatory reaction of the skin. The most pronounced erythema is caused by rays with wavelengths of about 290 mμ. With an overdose of ultraviolet radiation, erythema becomes bluish, the edges of erythema become blurry, the irradiated area is swollen and painful. Intense irradiation can cause a burn with the development of a bubble.

Sensitivity of different parts of the skin to ultraviolet light

The skin of the abdomen, lower back, lateral surfaces of the chest are most sensitive to ultraviolet rays. The skin of the hands and face is the least sensitive.

Persons with delicate, slightly pigmented skin, children, as well as those suffering from Graves' disease and vegetative dystonia are more sensitive. Increased sensitivity of the skin to ultraviolet rays is observed in spring.

It has been established that the sensitivity of the skin to ultraviolet rays can vary depending on the physiological state of the body. The development of an erythemal reaction depends primarily on the functional state of the nervous system.

In response to ultraviolet irradiation, a pigment is formed and deposited in the skin, which is a product of skin protein metabolism (organic coloring matter - melanin).

Long-wave UV rays cause a more intense tan than short-wave UV rays. With repeated ultraviolet irradiation, the skin becomes less susceptible to these rays. Skin pigmentation often develops without previously visible erythema. In pigmented skin, ultraviolet rays do not cause photoerythema.

The positive effect of ultraviolet radiation

Ultraviolet rays reduce the excitability of sensory nerves (analgesic effect) and also have an antispastic and antirachitic effect. Under the influence of ultraviolet rays, the formation of vitamin D, which is very important for phosphorus-calcium metabolism, occurs (ergosterol in the skin is converted into vitamin D). Under the influence of ultraviolet rays, oxidative processes in the body increase, oxygen absorption by tissues and carbon dioxide release increase, enzymes are activated, protein and carbohydrate metabolism improves. The content of calcium and phosphates in the blood increases. Blood formation, regenerative processes, blood supply and tissue trophism improve. Skin vessels dilate, blood pressure decreases, and the overall biotonus of the body increases.

The beneficial effect of ultraviolet rays is expressed in a change in the immunobiological reactivity of the body. Irradiation stimulates the production of antibodies, increases phagocytosis, tones the reticuloendothelial system. This increases the body's resistance to infections. The dosage of radiation is important in this respect.

A number of substances of animal and vegetable origin (hematoporphyrin, chlorophyll, etc.), some chemicals (quinine, streptocide, sulfidine, etc.), especially fluorescent paints (eosin, methylene blue, etc.), have the property increase the body's sensitivity to light. In industry, people working with coal tar have skin diseases of exposed parts of the body (itching, burning, redness), and these phenomena disappear at night. This is due to the photosensitizing properties of acridine contained in coal tar. Sensitization occurs predominantly in relation to visible rays and to a lesser extent in relation to ultraviolet rays.

Of great practical importance is the ability of ultraviolet rays to kill various bacteria (the so-called bactericidal effect). This action is especially pronounced in ultraviolet rays with wavelengths less than (265 - 200 mμ). The bactericidal effect of light is associated with the effect on the protoplasm of bacteria. It has been proven that mitogenetic radiation in cells and blood increases after ultraviolet irradiation.

According to modern concepts, the action of light on the body is based mainly on the reflex mechanism, although great importance is also attached to humoral factors. This is especially true for the action of ultraviolet rays. One must also keep in mind the possibility of the action of visible rays through the organs of vision on the cortex and vegetative centers.

In the development of erythema caused by light, significant importance is attached to the influence of rays on the receptor apparatus of the skin. When exposed to ultraviolet rays, as a result of the breakdown of proteins in the skin, histamine and histamine-like products are formed, which dilate the skin vessels and increase their permeability, which leads to hyperemia and swelling. The products formed in the skin under the influence of ultraviolet rays (histamine, vitamin D, etc.) enter the bloodstream and cause those general changes in the body that occur during irradiation.

Thus, the processes developing in the irradiated area lead in a neurohumoral way to the development of a general reaction of the organism. This reaction is determined mainly by the state of the higher regulatory divisions of the central nervous system, which, as you know, can change under the influence of various factors.

It is impossible to talk about the biological effect of ultraviolet radiation in general, regardless of the wavelength. Short-wave ultraviolet radiation causes denaturation of protein substances, long-wave - photolytic decay. The specific action of different sections of the spectrum of ultraviolet radiation is revealed mainly in the initial stage.

Application of ultraviolet radiation

The wide biological effect of ultraviolet rays makes it possible to use them in certain doses for preventive and therapeutic purposes.

For ultraviolet irradiation, sunlight is used, as well as artificial sources of irradiation: mercury-quartz and argon-mercury-quartz lamps. The emission spectrum of mercury-quartz lamps is characterized by the presence of shorter ultraviolet rays than in the solar spectrum.

Ultraviolet irradiation can be general or local. The dosage of procedures is carried out according to the principle of biodoses.

Currently, ultraviolet irradiation is widely used, primarily for the prevention of various diseases. For this purpose, ultraviolet irradiation is used to improve the human environment and change its reactivity (primarily to increase its immunobiological properties).

With the help of special bactericidal lamps, air can be sterilized in medical institutions and residential premises, sterilization of milk, water, etc. Ultraviolet irradiation is widely used to prevent rickets, influenza, in order to generally strengthen the body in medical and children's institutions, schools, gyms , fotaria at coal mines, during training of athletes, for acclimatization to the conditions of the north, when working in hot shops (ultraviolet irradiation gives a greater effect in combination with infrared radiation).

Ultraviolet rays are especially widely used for irradiating children. First of all, such exposure is shown to weakened, often ill children living in the northern and middle latitudes. At the same time, the general condition of children improves, sleep increases, weight increases, morbidity decreases, the frequency of catarrhal phenomena and the duration of diseases decrease. Improves overall physical development, normalizes blood, vascular permeability.

Ultraviolet irradiation of miners in fotaria, which are organized in large numbers at mining enterprises, has also become widespread. With systematic mass exposure of miners engaged in underground work, there is an improvement in well-being, an increase in working capacity, a decrease in fatigue, a decrease in morbidity with temporary disability. After irradiation of miners, the percentage of hemoglobin increases, monocytosis appears, the number of cases of influenza decreases, the incidence of the musculoskeletal system, the peripheral nervous system decreases, pustular skin diseases, catarrhs ​​of the upper respiratory tract and tonsillitis are less common, and the readings of vital capacity and lungs improve.

The use of ultraviolet radiation in medicine

The use of ultraviolet rays for therapeutic purposes is based mainly on the anti-inflammatory, anti-neuralgic and desensitizing effects of this type of radiant energy.

In combination with other therapeutic measures, ultraviolet irradiation is carried out:

1) in the treatment of rickets;

2) after suffering infectious diseases;

3) in case of tuberculosis diseases of bones, joints, lymph nodes;

4) with fibrous pulmonary tuberculosis without phenomena indicating activation of the process;

5) in diseases of the peripheral nervous system, muscles and joints;

6) with skin diseases;

7) with burns and frostbite;

8) with purulent complications of wounds;

9) with resorption of infiltrates;

10) in order to accelerate regenerative processes in case of injuries of bones and soft tissues.

Contraindications to radiation are:

1) malignant neoplasms (since radiation accelerates their growth);

2) severe exhaustion;

3) increased function of the thyroid gland;

4) severe cardiovascular diseases;

5) active pulmonary tuberculosis;

6) kidney disease;

7) pronounced changes in the central nervous system.

It should be remembered that obtaining pigmentation, especially in the short term, should not be the goal of treatment. In some cases, a good therapeutic effect is observed with weak pigmentation.

The negative effect of ultraviolet radiation

Prolonged and intense ultraviolet irradiation can have an adverse effect on the body and cause pathological changes. With significant exposure, fatigue, headaches, drowsiness, memory impairment, irritability, palpitations, and loss of appetite are noted. Excessive exposure can cause hypercalcemia, hemolysis, growth retardation and decreased resistance to infection. With strong exposure, burns and dermatitis develop (burning and itching of the skin, diffuse erythema, swelling). At the same time, there is an increase in body temperature, headache, weakness. Burns and dermatitis that occur under the influence of solar radiation are associated mainly with the influence of ultraviolet rays. People working outdoors under the influence of solar radiation may develop long-term and severe dermatitis. It is necessary to remember about the possibility of the transition of the described dermatitis into cancer.

Depending on the depth of penetration of the rays of different parts of the solar spectrum, changes in the eyes may develop. Under the influence of infrared and visible rays, acute retinitis occurs. The so-called glassblower's cataract, which develops as a result of prolonged absorption of infrared rays by the lens, is well known. Clouding of the lens occurs slowly, mainly among workers in hot shops with work experience of 20-25 years or more. Currently, professional cataracts in hot shops are rare due to a significant improvement in working conditions. The cornea and conjunctiva react mainly to ultraviolet rays. These rays (especially with a wavelength of less than 320 mμ.) cause in some cases an eye disease known as photophthalmia or electrophthalmia. This disease is most common in electric welders. In such cases, acute keratoconjunctivitis is often observed, which usually occurs 6-8 hours after work, often at night.

With electrophthalmia, hyperemia and swelling of the mucosa, blepharospasm, photophobia, and lacrimation are noted. Corneal lesions are often found. The duration of the acute period of the disease is 1-2 days. Photophthalmia sometimes occurs in people working outdoors in bright sunlight in wide snow-covered spaces in the form of so-called snow blindness. Treatment of photophthalmia is to stay in the dark, the use of novocaine and cold lotions.

UV protection

To protect the eyes from the adverse effects of ultraviolet rays in production, they use shields or helmets with special dark glasses, goggles, and to protect the rest of the body and surrounding people - insulating screens, portable screens, and overalls.

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 an altitude 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"; "FROM". 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 ozonization 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 a microbiological quality standard, 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.

With the discovery of infrared radiation, the well-known German physicist Johann Wilhelm Ritter had a desire to study the opposite side of this phenomenon.

After some time, he managed to find out that at the other end it has considerable chemical activity.

This spectrum became known as ultraviolet rays. What it is and what effect it has on living terrestrial organisms, let's try to figure it out further.

Both radiations are in any case electromagnetic waves. Both infrared and ultraviolet, they limit the spectrum of light perceived by the human eye on both sides.

The main difference between these two phenomena is the wavelength. Ultraviolet has a fairly wide wavelength range - from 10 to 380 microns and is located between visible light and X-rays.

Differences between infrared and ultraviolet

IR radiation has the main property - to radiate heat, while ultraviolet has a chemical activity, which has a tangible effect on the human body.

How does ultraviolet radiation affect humans?

Due to the fact that UV is divided by the difference in wavelength, they biologically affect the human body in different ways, so scientists distinguish three sections of the ultraviolet range: UV-A, UV-B, UV-C: near, middle and far ultraviolet.

The atmosphere that envelops our planet acts as a protective shield that protects it from the Sun's ultraviolet flux. Far radiation is retained and absorbed almost completely by oxygen, water vapor, carbon dioxide. Thus, insignificant radiation enters the surface in the form of near and medium radiation.

The most dangerous is radiation with a short wavelength. If short-wave radiation falls on living tissues, it provokes an instant destructive effect. But due to the fact that our planet has an ozone shield, we are safe from the effects of such rays.

IMPORTANT! Despite natural protection, we use some inventions in everyday life that are sources of this particular range of rays. These are welding machines and ultraviolet lamps, which, unfortunately, cannot be abandoned.

Biologically, ultraviolet affects human skin as a slight redness, sunburn, which is a fairly mild reaction. But it is worth considering the individual feature of the skin, which can specifically respond to UV radiation.

Exposure to UV rays also adversely affects the eyes. Many are aware that ultraviolet affects the human body in one way or another, but not everyone knows the details, so we will try to understand this topic in more detail.

UV mutagenesis or how UV affects human skin

It is impossible to completely refuse the sun's rays on the skin, this leads to extremely unpleasant consequences.

But it is also contraindicated to go to extremes and try to acquire an attractive shade of the body, exhausting yourself under the merciless rays of the sun. What can happen in case of uncontrolled stay under the scorching sun?

If redness of the skin is found, this is not a sign that after a while, it will pass and a nice, chocolate tan will remain. The skin is darker due to the fact that the body produces a coloring pigment, melanin, which fights against the adverse effects of UV on our body.

Moreover, redness on the skin does not remain long, but it can lose elasticity forever. Epithelial cells may also begin to grow, visually reflected in the form of freckles and age spots, which will also remain for a long time, or even forever.

Penetrating deep into tissues, ultraviolet light can lead to ultraviolet mutagenesis, which is damage to cells at the gene level. The most dangerous can be melanoma, in case of metastasis of which death can occur.

How to protect yourself from ultraviolet radiation?

Is it possible to protect the skin from the negative effects of ultraviolet radiation? Yes, if, while on the beach, you follow just a few rules:

1. It is necessary to be under the scorching sun for a short time and at strictly defined hours, when the acquired light tan acts as photoprotection of the skin.
2. Be sure to use sunscreen. Before you buy this kind of product, be sure to check if it can protect you from UV-A and UV-B.
3. It is worth including in the diet foods that contain the maximum amount of vitamins C and E, as well as rich in antioxidants.

If you are not on the beach, but are forced to be in the open air, you should choose special clothes that can protect your skin from UV.

Electrophthalmia - the negative effect of UV radiation on the eyes

Electrophthalmia is a phenomenon that occurs as a result of the negative effects of ultraviolet radiation on the structure of the eye. UV waves from the middle ranges in this case are very damaging to human vision.

Electrophthalmia

These events most often occur when:

• A person observes the sun, its location, without protecting the eyes with special devices;
• Bright sun in open space (beach);
• The person is in a snowy area, in the mountains;
• Quartz lamps are placed in the room where the person is located.

Electrophthalmia can lead to corneal burns, the main symptoms of which are:

• Tearing of the eyes;
• Significant pain;
• Fear of bright light;
• Redness of the protein;
• Edema of the epithelium of the cornea and eyelids.

About statistics, the deep layers of the cornea do not have time to be damaged, therefore, when the epithelium heals, vision is fully restored.

How to provide first aid for electrophthalmia?

If a person is faced with the above symptoms, it is not only aesthetically unpleasant, but can also cause unimaginable suffering.

First aid is pretty simple:

• First rinse eyes with clean water;
• Then apply moisturizing drops;
• Put on glasses;

To get rid of pain in the eyes, it is enough to make a compress from wet black tea bags, or grate raw potatoes. If these methods do not help, you should immediately seek help from a specialist.

To avoid such situations, it is enough to purchase social sunglasses. The UV-400 marking indicates that this accessory is able to protect the eyes from all UV radiation.

How is UV radiation used in medical practice?

In medicine, there is the concept of "ultraviolet starvation", which can occur in case of prolonged avoidance of sunlight. In this case, unpleasant pathologies may arise, which can be easily avoided using artificial sources of ultraviolet radiation.

Their small impact is able to compensate for the lack of winter vitamin D deficiency.

In addition, such therapy is applicable in case of joint problems, skin diseases and allergic reactions.

With UV radiation, you can:

• Increase hemoglobin, but lower sugar levels;
• Normalize the work of the thyroid gland;
• Improve and eliminate problems of the respiratory and endocrine system;
• With the help of installations with ultraviolet radiation, rooms and surgical instruments are disinfected;
• UV rays have bactericidal properties, which is especially useful for patients with purulent wounds.

IMPORTANT! Always, using such radiation in practice, it is worth familiarizing yourself not only with the positive, but also with the negative aspects of their impact. It is strictly forbidden to use artificial, as well as natural UV radiation as a treatment for oncology, bleeding, stage 1 and 2 hypertension, and active tuberculosis.

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 the 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 exposure, 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;
• cardiopalmus;
• 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. That's why 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 regulations are not observed when working with welding equipment or in people who are in bright sunlight in a snow-covered area (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 the 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 impact of ultraviolet radiation on the human body and its health cannot be unambiguously 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.

We most often observe the use of ultraviolet radiation for cosmetic and medical purposes. Also, ultraviolet radiation is used in printing, in the disinfection and disinfection of water and air, if necessary, polymerization and changes in the physical state of materials.

Ultraviolet radiation is a type of radiation that has a certain wavelength and occupies an intermediate position between the X-ray and the violet zone of visible radiation. This radiation is invisible to the human eye. However, due to its properties, such radiation has become very widespread and is used in many areas.

Currently, many scientists are purposefully studying the effect of ultraviolet radiation on many life processes, including metabolic, regulatory, and trophic ones. It is known that ultraviolet radiation has a beneficial effect on the body in certain diseases and disorders, contributing to the treatment. That is why it has been widely used in the field of medicine.

Thanks to the work of many scientists, the effect of ultraviolet radiation on biological processes in the human body has been studied so that these processes can be controlled.

UV protection is essential when the skin is exposed to the sun for a long time.

It is believed that it is ultraviolet rays that are responsible for photoaging of the skin, as well as for the development of carcinogenesis, since when exposed to them, a lot of free radicals that adversely affect all processes in the body.
In addition, when using ultraviolet radiation, the risk of damaging DNA chains is very high, and this can already lead to very tragic consequences and the emergence of such terrible diseases as cancer and others.

Do you know what can be useful for a person? About such properties, as well as about the properties of ultraviolet radiation, which allow it to be used in various production processes, you can learn everything from our article.

We also have an overview available. Read our material and you will understand all the main differences between natural and artificial light sources.

The main natural source of this type of radiation is the sun. And among the artificial ones, there are several types:

• Erythema lamps (invented in the 60s, used mainly to compensate for the lack of natural ultraviolet radiation. For example, to prevent rickets in children, to irradiate the young generation of farm animals, in fotaria)
• Mercury-quartz lamps
• Excilamps
• germicidal lamps
• Fluorescent lamps
• LEDs

Many lamps emitting in the ultraviolet range are designed to illuminate rooms and other objects, and the principle of their operation is associated with ultraviolet radiation, which is converted in various ways into visible light.

Ways to generate ultraviolet radiation:

• Temperature radiation (used in incandescent lamps)
• Radiation created due to gases and metal vapors moving in an electric field (used in mercury and gas discharge lamps)
• Luminescence (used in erythema, bactericidal lamps)

The use of ultraviolet radiation due to its properties

The industry produces many types of lamps for various applications of ultraviolet radiation:

• Mercury
• Hydrogen
• Xenon

The main properties of UV - radiation, which determine its use:

• High chemical activity (contributes to the acceleration of many chemical reactions, as well as the acceleration of biological processes in the body):
  Under the influence of ultraviolet radiation, vitamin D and serotonin are formed in the skin, the tone and vital activity of the body improves.
• Ability to kill various microorganisms (bactericidal property):
  The use of ultraviolet germicidal radiation contributes to air disinfection, especially in places where many people gather (hospitals, schools, universities, railway stations, subways, large stores).
  Disinfection of water with ultraviolet radiation is also in great demand, as it gives good results. With this method of purification, water does not acquire an unpleasant odor and taste. It is great for water purification in fish farms, swimming pools.
  The ultraviolet disinfection method is often used during processing surgical instruments.
• The ability to cause luminescence of certain substances:
  Thanks to this property, forensic experts detect traces of blood on various objects. And also thanks to special paint you can detect marked banknotes that are used in anti-corruption operations.

Application of ultraviolet radiation photo

Below are photos on the topic of the article "The use of ultraviolet radiation." To open the photo gallery, just click on the image thumbnail.