It also has ultraviolet radiation. Effect of ultraviolet radiation on the human body

Happy opening infrared radiation the once famous 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 the other end has considerable chemical activity.

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

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

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

IR radiation has the main property of emitting heat, while ultraviolet radiation has chemical activity, which has a noticeable effect on human body.

How does ultraviolet radiation affect humans?

Due to the fact that UV is divided according to 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 solar ultraviolet stream. Far radiation is retained and absorbed almost completely by oxygen, water vapor, carbon dioxide. Thus, minor radiation reaches the surface in the form of near and mid-range radiation.

The most dangerous is radiation with a short wavelength. If short-wave radiation falls on living tissue, it provokes an immediate destructive effect. But thanks 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 radiation affects human skin as slight redness and tanning, which is a fairly mild reaction. But it's worth considering individual feature skin that can specifically react to UV radiation.

Exposure to UV rays also has adverse effects on the eyes. Many people are aware that ultraviolet radiation somehow affects the human body, 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

Refuse to hit completely sun rays You can’t apply it to the skin; it will lead to extremely unpleasant consequences.

But it is also contraindicated to go to extremes and try to acquire an attractive body shade, exhausting yourself under the merciless rays of the sun. What can happen if you are uncontrollably exposed to the scorching sun?

If redness of the skin is detected, this is not a sign that after some time 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 the adverse effects of UV on our body.

Moreover, redness on the skin does not last long, but it may lose its 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 tissue, ultraviolet radiation can lead to ultraviolet mutagenesis, which is cell damage at the gene level. The most dangerous can be melanoma, which can cause death if it metastasizes.

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 stay under the scorching sun for a short time and at strictly certain hours, when the acquired light tan will act as photoprotection for the skin.
2. Be sure to use sunscreen. Before you buy this type of product, be sure to check whether it can protect you from UVA and UVB.
3. It is worth including in your diet foods containing maximum amount vitamins C and E, as well as rich in antioxidants.

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

Electroophthalmia - the negative effect of UV radiation on the eyes

Electroophthalmia is a phenomenon that occurs due to the negative effects of ultraviolet radiation on the structure of the eye. Mid-range UV waves in this case are very destructive to human vision.

These phenomena most often occur when:

• A person watches the sun and its location without protecting his eyes with special devices;
• Bright sun in an open space (beach);
• A person is in a snowy area, in the mountains;
• In the room where the person is located, there are quartz lamps.

Electroophthalmia can lead to a corneal burn, the main symptoms of which include:

• Watery eyes;
• Significant pain;
• Fear of bright light;
• Redness of the white;
• Swelling 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 completely restored.

How to provide first aid for electroophthalmia?

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

First aid is quite simple:

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

To get rid of the pain in the eyes, just 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 similar situations, just buy 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 fasting,” which can occur in the event of prolonged avoidance of sunlight. In this case, unpleasant pathologies may arise, which can be easily avoided by using artificial ultraviolet sources.

Their small exposure can compensate for the winter vitamin D deficiency.

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

Using UV radiation you can:

• Increase hemoglobin, but reduce sugar levels;
• Normalize the functioning of the thyroid gland;
• Improve and eliminate problems of the respiratory and endocrine systems;
• Using installations with ultraviolet radiation, premises and surgical instruments are disinfected;
• UV rays have bactericidal properties, which is especially useful for patients with purulent wounds.

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

General characteristics of ultraviolet radiation

Note 1

Ultraviolet radiation discovered I.V. Ritter in $1842$. Subsequently, the properties of this radiation and its application were subjected to the most careful analysis and study. Scientists such as A. Becquerel, Warshawer, Danzig, Frank, Parfenov, Galanin and many others made a great contribution to this study.

Currently ultraviolet radiation widely used in different areas activities. Ultraviolet activity reaches its peak in the high temperature range. This type of spectrum appears when the temperature reaches from $1500$ to $20000$ degrees.

Conventionally, the radiation range is divided into 2 areas:

1. Near spectrum, which reaches the Earth from the Sun through the atmosphere and has a wavelength of $380$-$200$ nm;
2. Distant Spectrum absorbed by ozone, air oxygen and other atmospheric components. This spectrum can be studied using special vacuum devices, which is why it is also called vacuum. Its wavelength is $200$-$2$ nm.

Ultraviolet radiation can be short-range, long-range, extreme, medium, vacuum, and each type has its own properties and finds its own application. Each type of ultraviolet radiation has its own wavelength, but within the limits indicated above.

Spectrum of ultraviolet sunlight, reaching the Earth's surface, is narrow - $400$...$290$ nm. It turns out that the Sun does not emit light with a wavelength shorter than $290$ nm. Is this true or not? The answer to this question was found by a Frenchman A. Cornu, who established that ultra-violet rays In short, $295$ nm are absorbed by ozone. Based on this, A. Cornu suggested that the Sun emits short-wave ultraviolet radiation. Oxygen molecules under its influence disintegrate into individual atoms and form ozone molecules. Ozone V upper layers atmosphere covers the planet protective screen.

Scientist's guess confirmed when man managed to rise to the upper layers of the atmosphere. The height of the Sun above the horizon and the amount of ultraviolet rays reaching the earth's surface are directly related. When the illumination changes by $20$%, the amount of ultraviolet rays reaching the surface will decrease by $20$ times. Experiments have shown that for every $100$ m of ascent, the intensity of ultraviolet radiation increases by $3$-$4$%. In the equatorial region of the planet, when the Sun is at its zenith, rays with a length of $290$...$289$ nm reach the earth's surface. The earth's surface above the Arctic Circle receives rays with a wavelength of $350$...$380$ nm.

Ultraviolet radiation sources

Ultraviolet radiation has its sources:

1. Natural springs;
2. Man-made sources;
3. Laser sources.

Natural source ultraviolet rays is their only concentrator and emitter - this is our Sun. The star closest to us emits a powerful charge of waves that can pass through ozone layer and achieve earth's surface. Numerous studies have allowed scientists to put forward the theory that only with the advent of the ozone layer on the planet could life arise. It is this layer that protects all living things from harmful excessive penetration of ultraviolet radiation. The ability for the existence of protein molecules, nucleic acids and ATP became possible precisely during this period. Ozone layer performs very important function, interacting with the bulk UV-A, UV-B, UV-C, it neutralizes them and does not allow them to reach the surface of the Earth. Ultraviolet radiation arriving at the earth's surface has a range that ranges from $200$ to $400$ nm.

The concentration of ultraviolet radiation on Earth depends on a number of factors:

1. The presence of ozone holes;
2. Position of the territory (height) above sea level;
3. The height of the Sun itself;
4. The ability of the atmosphere to scatter rays;
5. Reflectivity of the underlying surface;
6. States of cloud vapors.

Artificial sources Ultraviolet radiation is usually created by humans. These can be human-designed instruments, devices, technical means. They are created to obtain the desired spectrum of light with given parameters wavelength. The purpose of their creation is so that the resulting ultraviolet radiation can be usefully used in various fields of activity.

To sources artificial origin relate:

1. Having the ability to activate the synthesis of vitamin D in human skin erythema lamps. They not only protect against rickets, but also treat this disease;
2. Special apparatus for solariums, preventing winter depression and giving a beautiful natural tan;
3. Used indoors to control insects attractant lamps. They pose no danger to humans;
4. Mercury-quartz devices;
5. Excilamps;
6. Luminescent devices;
7. Xenon lamps;
8. Gas discharge devices;
9. High temperature plasma;
10. Synchrotron radiation in accelerators.

TO artificial sources ultraviolet radiation include lasers, whose operation is based on the generation of inert and non-inert gases. This can be nitrogen, argon, neon, xenon, organic scintillators, crystals. Currently exists laser working for free electrons . It produces the length of ultraviolet radiation equal to that, which is observed under vacuum conditions. Laser ultraviolet is used in biotechnological, microbiological research, mass spectrometry, etc.

Application of ultraviolet radiation

Ultraviolet radiation has characteristics that allow it to be used in various fields.

UV characteristics:

1. High level of chemical activity;
2. Bactericidal effect;
3. The ability to cause luminescence, i.e. glow various substances different shades.

Based on this, ultraviolet radiation can be widely used, for example, in spectrometric analyses, astronomy, medicine, and disinfection drinking water, analytical study of minerals, for the destruction of insects, bacteria and viruses. Each area uses a different type of UV with its own spectrum and wavelength.

Spectrometry specializes in identifying compounds and their composition by their ability to absorb UV light of a specific wavelength. Based on the results of spectrometry, the spectra for each substance can be classified, because they are unique. The destruction of insects is based on the fact that their eyes detect short-wave spectra that are invisible to humans. Insects fly to this source and are destroyed. Special installations in solariums expose the human body to UV-A. As a result, melanin production is activated in the skin, which gives it a darker and more even color. Here, of course, it is important to protect sensitive areas and eyes.

Medicine. The use of ultraviolet radiation in this area is also associated with the destruction of living organisms - bacteria and viruses.

Medical indications for ultraviolet treatment:

1. Trauma to tissues, bones;
2. Inflammatory processes;
3. Burns, frostbite, skin diseases;
4. Acute respiratory diseases, tuberculosis, asthma;
5. Infectious diseases, neuralgia;
6. Diseases of the ear, nose and throat;
7. Rickets and trophic gastric ulcers;
8. Atherosclerosis, renal failure, etc.

This is not the entire list of diseases for which ultraviolet radiation is used.

Note 2

Thus, ultraviolet helps doctors save millions human lives and restore their health. Ultraviolet light is also used to disinfect premises and sterilize medical instruments and work surfaces.

Analytical work with minerals. Ultraviolet causes luminescence in substances and this makes it possible to use it to analyze the qualitative composition of minerals and valuable rocks. Very interesting results produce precious, semi-precious and ornamental stones. When irradiated with cathode waves, they give amazing and unique shades. The blue color of topaz, for example, when irradiated turns out to be bright green, emerald - red, pearls shimmer with multicolors. The spectacle is amazing, fantastic.

We most often see the use of ultraviolet radiation for cosmetic and medical purposes. Ultraviolet radiation is also used in printing, in the disinfection and disinfection of water and air, and when it is necessary to polymerize and change the physical state of materials.

Ultraviolet healing is a type of radiation that has a specific wavelength and occupies intermediate position between X-ray and violet zone visible radiation. Such 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 vital processes, including metabolic, regulatory, and trophic ones. It is known that ultraviolet radiation has a beneficial effect on the body in some diseases and disorders, promoting treatment. That is why it has become widely used in the medical field.

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

UV protection is necessary in cases where the skin is exposed to prolonged sunlight.

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 their exposure produces a lot of free radicals , adversely affecting all processes in the body.
In addition, when using ultraviolet radiation, there is a very high risk of damage to DNA chains, and this can lead to very tragic consequences and the emergence of such terrible diseases as cancer and others.

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

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

Main natural source this type of radiation is the Sun. And among artificial ones there are several types:

• Erythema lamps (invented back in the 60s, used mainly to compensate for the insufficiency of natural ultraviolet radiation. For example, to prevent rickets in children, for irradiation younger generation farm animals, in photos)
• 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 different ways converted to visible light.

Methods for generating ultraviolet radiation:

• Temperature radiation (used in incandescent lamps)
• Radiation created by 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 ways Applications of ultraviolet radiation:

• Mercury
• Hydrogen
• Xenon

The main properties of UV radiation that determine its use:

• High chemical activity (helps accelerate many chemical reactions, as well as acceleration biological processes in organism):
  Under the influence of ultraviolet radiation, vitamin D and serotonin are formed in the skin, and the tone and vital functions of the body improve.
• Ability to kill various microorganisms (bactericidal property):
  The use of ultraviolet bactericidal radiation helps disinfect the air, especially in places where many people gather (hospitals, schools, higher education institutions) educational establishments, train stations, metro, large stores).
  Water disinfection with ultraviolet radiation is also in great demand as it gives good results. With this method of purification, the water does not acquire an unpleasant odor or taste. This is great for water purification in fish farms and swimming pools.
  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 special paint It is possible to detect tagged bills that are used in anti-corruption operations.

Application of ultraviolet radiation photo

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Solar energy consists of electromagnetic waves, which are divided into several parts of the spectrum:

• X-rays - with the shortest wavelength (below 2 nm);
• The wavelength of ultraviolet radiation is from 2 to 400 nm;
• the visible part of the light, which is captured by the eye of humans and animals (400-750 nm);
• warm oxidative (over 750 nm).

Each part has its own application and has great importance in the life of the planet and all its biomass. We will look at what rays in the range from 2 to 400 nm are, where they are used and what role they play in people’s lives.

History of the discovery of UV radiation

The first mentions date back to XIII century in the descriptions of a philosopher from India. He wrote about a violet light invisible to the eye that he discovered. However, the technical capabilities of that time were clearly insufficient to confirm this experimentally and study it in detail.

This was achieved five centuries later by a physicist from Germany, Ritter. It was he who conducted experiments on silver chloride on its decomposition under the influence electromagnetic radiation. The scientist saw that it was faster this process does not go in that region of light, which had already been discovered by that time and was called infrared, but in the opposite one. It turned out that this new area, has not yet been explored.

Thus, ultraviolet radiation was discovered in 1842, the properties and applications of which were subsequently subjected to careful analysis and study by various scientists. People such as Alexander Becquerel, Warshawer, Danzig, Macedonio Melloni, Frank, Parfenov, Galanin and others made a great contribution to this.

general characteristics

What is the application of which today is so widespread in various industries human activity? Firstly, it should be noted that this light appears only when very high temperatures from 1500 to 2000 0 C. It is in this range that UV reaches its peak activity in terms of exposure.

By physical nature This electromagnetic wave, the length of which varies quite widely - from 10 (sometimes from 2) to 400 nm. The entire range of this radiation is conventionally divided into two areas:

1. Near spectrum. Reaches the Earth through the atmosphere and ozone layer from the Sun. Wavelength - 380-200 nm.
2. Distant (vacuum). Actively absorbed by ozone, air oxygen, and atmospheric components. It can only be explored with special vacuum devices, which is why it got its name. Wavelength - 200-2 nm.

There is a classification of types that have ultraviolet radiation. Each of them finds properties and applications.

1. Near.
2. Further.
3. Extreme.
4. Average.
5. Vacuum.
6. Long-wave black light (UV-A).
7. Shortwave germicidal (UV-C).
8. Mid-wave UV-B.

The wavelength of ultraviolet radiation is different for each type, but they are all within the general limits already outlined earlier.

The interesting one is UV-A, or so-called black light. The fact is that this spectrum has a wavelength from 400-315 nm. This is on the borderline with visible light, which the human eye is capable of detecting. Therefore, such radiation passing through certain items or tissue, is capable of transitioning into the region of visible violet light, and people distinguish it as a black, dark blue or dark purple hue.

The spectra produced by ultraviolet radiation sources can be of three types:

• ruled;
• continuous;
• molecular (band).

The first are characteristic of atoms, ions, and gases. The second group is for recombination, bremsstrahlung. Sources of the third type are most often encountered in the study of rarefied molecular gases.

Ultraviolet radiation sources

The main sources of UV rays fall into three broad categories:

• natural or natural;
• artificial, man-made;
• laser

The first group includes a single type of concentrator and emitter - the Sun. Exactly celestial body gives a powerful charge of this type of waves that are able to pass through and reach the surface of the Earth. However, not with its entire mass. Scientists put forward the theory that life on Earth arose only when the ozone screen began to protect it from excessive penetration of harmful UV radiation in high concentrations.

It was during this period that they became able to exist protein molecules, nucleic acids and ATP. Before today The ozone layer comes into close interaction with the bulk of UVA, UVB and UV-C, neutralizing them and not allowing them to pass through. Therefore, protection of the entire planet from ultraviolet radiation is solely his merit.

What determines the concentration of ultraviolet radiation penetrating the Earth? There are several main factors:

• ozone holes;
• height above sea level;
• solstice altitude;
• atmospheric dispersion;
• the degree of reflection of rays from the earth's natural surfaces;
• state of cloud vapors.

The range of ultraviolet radiation penetrating the Earth from the Sun ranges from 200 to 400 nm.

The following sources are artificial. These include all those instruments, devices, technical means that were designed by man to obtain the desired spectrum of light with given wavelength parameters. This was done in order to obtain ultraviolet radiation, the use of which can be extremely useful in various fields of activity. Artificial sources include:

1. Erythemal lamps that have the ability to activate the synthesis of vitamin D in the skin. This protects against rickets and treats it.
2. Devices for solariums, in which people not only get a beautiful natural tan, but are also treated for diseases that arise from a lack of open sunlight (the so-called winter depression).
3. Attractant lamps that allow you to fight insects indoors safely for humans.
4. Mercury-quartz devices.
5. Excilamp.
6. Luminescent devices.
7. Xenon lamps.
8. Gas discharge devices.
9. High temperature plasma.
10. Synchrotron radiation in accelerators.

Another type of source is lasers. Their work is based on the generation of various gases - both inert and not. Sources may be:

• nitrogen;
• argon;
• neon;
• xenon;
• organic scintillators;
• crystals.

More recently, about 4 years ago, a laser operating on free electrons was invented. The length of ultraviolet radiation in it is equal to that observed under vacuum conditions. UV laser suppliers are used in biotechnology, microbiology research, mass spectrometry and so on.

Biological effects on organisms

The effect of ultraviolet radiation on living beings is twofold. On the one hand, with its deficiency, diseases can occur. This became clear only at the beginning of the last century. Artificial irradiation with special UV-A at the required standards is capable of:

• activate the immune system;
• cause the formation of important vasodilatory compounds (histamine, for example);
• strengthen the skin-muscular system;
• improve lung function, increase the intensity of gas exchange;
• influence the speed and quality of metabolism;
• increase the tone of the body by activating the production of hormones;
• increase the permeability of the walls of blood vessels on the skin.

If UV-A is in sufficient quantity enters the human body, then he does not develop diseases such as winter depression or light starvation, and the risk of developing rickets is also significantly reduced.

The effects of ultraviolet radiation on the body are of the following types:

• bactericidal;
• anti-inflammatory;
• regenerating;
• painkiller.

These properties largely explain the widespread use of UV in medical institutions any type.

However, in addition to the above advantages, there are also negative sides. There are a number of diseases and ailments that can be acquired if you do not receive additional amounts or, on the contrary, take in excess quantities of the waves in question.

1. Skin cancer. This is the most dangerous exposure to ultraviolet radiation. Melanoma can form due to excessive exposure to waves from any source - both natural and man-made. This is especially true for those who tan in solariums. In everything, moderation and caution are necessary.
2. Destructive effect on the retina of the eyeballs. In other words, cataracts, pterygium, or membrane burns may develop. The harmful excess effects of UV on the eyes have been proven by scientists for a long time and confirmed by experimental data. Therefore, when working with such sources, you should be careful. You can protect yourself on the street with the help of dark glasses. However, in this case, you should be wary of fakes, because if the glass is not equipped with UV-repellent filters, then the destructive effect will be even stronger.
3. Burns on the skin. IN summer time you can earn them if for a long time uncontrolled exposure to UV. In winter, you can get them due to the peculiarity of snow to reflect almost completely these waves. Therefore, irradiation occurs both from the Sun and from the snow.
4. Aging. If people are exposed to UV for a long time, then they begin to show signs of skin aging very early: dullness, wrinkles, sagging. This occurs because the protective barrier functions of the integument are weakened and disrupted.
5. Exposure with consequences over time. Lies in manifestations negative impacts not at a young age, but closer to old age.

All these results are the consequences of violation of UV dosages, i.e. they arise when the use of ultraviolet radiation is carried out irrationally, incorrectly, and without observing safety measures.

Ultraviolet radiation: application

The main areas of use are based on the properties of the substance. This is also true for spectral wave radiation. Thus, the main characteristics of UV on which its use is based are:

• high level chemical activity;
• bactericidal effect on organisms;
• the ability to cause various substances to glow in different shades, visible to the eye human (luminescence).

This allows for widespread use of ultraviolet radiation. Application possible in:

• spectrometric analyses;
• astronomical research;
• medicine;
• sterilization;
• disinfection of drinking water;
• photolithography;
• analytical study of minerals;
• UV filters;
• for catching insects;
• to get rid of bacteria and viruses.

Each of these areas uses a specific type of UV with its own spectrum and wavelength. IN Lately this type radiation is actively used in physical and chemical research(establishment electronic configuration atoms, crystal structure molecules and various compounds, work with ions, analysis of physical transformations on various space objects).

There is another feature of the effect of UV on substances. Some polymer materials capable of decomposing under the influence of an intense constant source of these waves. For example, such as:

• polyethylene of any pressure;
• polypropylene;
• polymethyl methacrylate or organic glass.

What is the impact? Products made from the listed materials lose color, crack, fade and, ultimately, collapse. Therefore, they are usually called sensitive polymers. This feature of carbon chain degradation under solar illumination conditions is actively used in nanotechnology, X-ray lithography, transplantology and other fields. This is done mainly to smooth out surface roughness of products.

Spectrometry - core area analytical chemistry, which specializes in identifying compounds and their composition based on their ability to absorb specific wavelengths of UV light. It turns out that the spectra are unique for each substance, so they can be classified according to the results of spectrometry.

Ultraviolet bactericidal radiation is also used to attract and destroy insects. The action is based on the ability of the insect's eye to detect short-wave spectra invisible to humans. Therefore, animals fly to the source, where they are destroyed.

Use in solariums - special vertical and horizontal installations in which human body exposed to UVA. This is done to activate the production of melanin in the skin, giving it more dark color, smoothness. In addition, this dries out inflammation and destroys harmful bacteria on the surface of the integument. Special attention should be given to protecting eyes and sensitive areas.

Medical field

The use of ultraviolet radiation in medicine is also based on its ability to destroy living organisms invisible to the eye - bacteria and viruses, and on the features that occur in the body during proper illumination with artificial or natural irradiation.

The main indications for UV treatment can be outlined in several points:

1. All types of inflammatory processes, wounds open type, suppuration and open sutures.
2. For tissue and bone injuries.
3. For burns, frostbite and skin diseases.
4. For respiratory ailments, tuberculosis, bronchial asthma.
5. Upon emergence and development various types infectious diseases.
6. For illnesses accompanied by severe painful sensations, neuralgia.
7. Diseases of the throat and nasal cavity.
8. Rickets and trophic
9. Dental diseases.
10. Regulation of blood pressure, normalization of heart function.
11. Development of cancerous tumors.
12. Atherosclerosis, renal failure and some other conditions.

All of these diseases can have very serious consequences for the body. Therefore, treatment and prevention using UV is a real medical discovery that saves thousands and millions of human lives, preserving and restoring their health.

Another option for using UV with medical and biological point vision - this is the disinfection of premises, sterilization of work surfaces and tools. The action is based on the ability of UV to inhibit the development and replication of DNA molecules, which leads to their extinction. Bacteria, fungi, protozoa and viruses die.

The main problem when using such radiation for sterilization and disinfection of a room is the area of ​​illumination. After all, organisms are destroyed only by direct exposure to direct waves. Everything that remains outside continues to exist.

Analytical work with minerals

The ability to cause luminescence in substances allows the use of UV to analyze the qualitative composition of minerals and valuable rocks. In this regard, precious, semi-precious and ornamental stones are very interesting. What shades do they produce when irradiated with cathode waves! Malakhov, the famous geologist, wrote about this very interestingly. His work talks about observations of the glow of the color palette that minerals can produce in different sources irradiation.

For example, topaz, which has a beautiful rich blue color in the visible spectrum, turns out bright green when irradiated, and emerald turns red. Pearls generally cannot give any specific color and shimmer in many colors. The resulting spectacle is simply fantastic.

If the composition of the rock under study includes uranium impurities, then the highlighting will show green color. Impurities of melite give a blue, and morganite - a lilac or pale purple hue.

Use in filters

Ultraviolet germicidal radiation is also used for use in filters. The types of such structures can be different:

• hard;
• gaseous;
• liquid.

Such devices are mainly used in the chemical industry, in particular in chromatography. With their help you can carry out qualitative analysis the composition of a substance and identify it by belonging to a particular class of organic compounds.

Drinking water treatment

Disinfection of drinking water with ultraviolet radiation is one of the most modern and qualitative methods its purification from biological impurities. The advantages of this method are as follows:

• reliability;
• efficiency;
• absence of foreign products in water;
• safety;
• efficiency;
• preservation of the organoleptic properties of water.

That is why today this disinfection technique keeps pace with traditional chlorination. The action is based on the same features - the destruction of the DNA of harmful living organisms in the water. UV with a wavelength of about 260 nm is used.

In addition to the direct effect on pests, ultraviolet light is also used to destroy residues chemical compounds, which are used to soften and purify water: such as, for example, chlorine or chloramine.

Black light lamp

Such devices are equipped with special emitters capable of producing long wavelengths, close to visible. However, they still remain indistinguishable to the human eye. Such lamps are used as reading devices secret signs from UV: for example, in passports, documents, banknotes and so on. That is, such marks can only be distinguished under the influence of a certain spectrum. This is how the operating principle of currency detectors and devices for checking the naturalness of banknotes is constructed.

Restoration and determination of the authenticity of the painting

And UV is used in this area. Each artist used white, containing different heavy metals. Thanks to irradiation, it is possible to obtain so-called underpaintings, which provide information about the authenticity of the painting, as well as about the specific technique and style of painting of each artist.

In addition, the varnish film on the surface of products is a sensitive polymer. Therefore, she is able to age when exposed to light. This allows us to determine the age of compositions and masterpieces of the artistic world.

The ultraviolet range of electromagnetic radiation lies beyond the violet (short wavelength) end of the visible spectrum.

Near ultraviolet light from the Sun passes through the atmosphere. It causes tanning on the skin and is necessary for the production of vitamin D. But excessive exposure can lead to the development of skin cancer. UV radiation is harmful to the eyes. Therefore, it is imperative to wear safety glasses on water and especially on snow in the mountains.

Harsher UV radiation is absorbed in the atmosphere by molecules of ozone and other gases. It can only be observed from space, and therefore it is called vacuum ultraviolet.

The energy of ultraviolet quanta is sufficient to destroy biological molecules, in particular DNA and proteins. One of the methods for destroying microbes is based on this. It is believed that as long as there was no ozone in the Earth's atmosphere, which absorbs a significant part of ultraviolet radiation, life could not leave the water on land.

Ultraviolet is emitted by objects with temperatures ranging from thousands to hundreds of thousands of degrees, for example, young hot massive stars. However, UV radiation is absorbed by interstellar gas and dust, so we often see not the sources themselves, but the cosmic clouds illuminated by them.

Mirror telescopes are used to collect UV radiation, and photomultiplier tubes are used for registration, and in the near UV, as in visible light- CCD matrices.

Sources

Glow occurs when charged particles solar wind collide with molecules of Jupiter's atmosphere. Most particles, under the influence of the planet's magnetic field, enter the atmosphere near it. magnetic poles. Therefore, the glow occurs in a relatively small area. Similar processes occur on Earth and on other planets that have an atmosphere and a magnetic field. The image was taken by the Hubble Space Telescope.

Receivers

Hubble Space Telescope

Sky Reviews

The survey was built by the orbiting ultraviolet observatory Extreme Ultraviolet Explorer (EUVE, 1992–2001). The line structure of the image corresponds to orbital motion satellite, and the inhomogeneity of the brightness of individual bands is associated with changes in the calibration of the equipment. Black stripes are areas of the sky that could not be observed. The small number of details in this review is due to the fact that there are relatively few sources of hard ultraviolet radiation and, in addition, ultraviolet radiation is scattered by cosmic dust.

Terrestrial Application

Installation for dosed irradiation of the body with near ultraviolet light for tanning. Ultraviolet radiation leads to the release of melanin pigment in cells, which changes skin color.

Doctors divide near ultraviolet light into three sections: UV-A (400–315 nm), UV-B (315–280 nm) and UV-C (280–200 nm). The mildest ultraviolet UV-A stimulates the release of melanin stored in melanocytes - the cellular organelles where it is produced. The harsher UV-B rays trigger the production of new melanin and also stimulate the production of vitamin D in the skin. Models of tanning beds differ in the power of radiation in these two areas of the UV range.

In sunlight at the Earth's surface, up to 99% of ultraviolet radiation is in the UV-A region, and the rest is in UV-B. Radiation in the UV-C range has a bactericidal effect; in the solar spectrum it is much less than UV-A and UV-B, in addition, most of it is absorbed in the atmosphere. Ultraviolet radiation causes drying and aging of the skin and contributes to the development cancer diseases. Moreover, radiation in the UV-A range increases the likelihood of dangerous looking skin cancer - melanoma.

UV-B radiation is almost completely blocked by protective creams, in contrast to UV-A, which penetrates through such protection and even partially through clothing. In general it is considered that very small doses UV-B is good for health, but the rest of the ultraviolet is harmful.

Ultraviolet radiation is used to determine the authenticity of banknotes. Polymer fibers with a special dye are pressed into banknotes, which absorbs ultraviolet quanta and then emits less energetic radiation in the visible range. Under the influence of ultraviolet light, the fibers begin to glow, which serves as one of the signs of authenticity.

The ultraviolet radiation of the detector is invisible to the eye; the blue glow, noticeable when most detectors operate, is due to the fact that the ultraviolet sources used also emit in the visible range.