Ultraviolet radiation in medicine, application. Effects of ultraviolet radiation on the human body

Ultraviolet radiation (ultraviolet, UV, UV) - electromagnetic radiation, occupying the range between the violet border of visible radiation and X-ray radiation (380 - 10 nm, 7.9 1014 - 3 1016 Hertz).

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

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

The electromagnetic spectrum of ultraviolet radiation can be divided into subgroups in different ways. The ISO standard for the definition of solar radiation (ISO-DIS-21348) gives the following definitions:

The near ultraviolet range is often referred to as "black light" because it is not recognizable by the human eye, but when reflected from some materials, the spectrum goes into the visible radiation region.

The term "vacuum" (VUV) is often used for the far and extreme range, due to the fact that waves in this range are strongly absorbed by the Earth's atmosphere.

The biological effects of ultraviolet radiation in the three spectral regions are significantly different, so biologists sometimes distinguish the following ranges as the most important in their work:

Near ultraviolet, UV-A rays (UVA, 315-400 nm)

UV-B rays (UVB, 280-315 nm)

Far ultraviolet, UV-C rays (UVC, 100-280nm)

Almost all UVC and approximately 90% UVB are absorbed by ozone, as well as water vapour, oxygen and carbon dioxide as sunlight passes through the earth's atmosphere. Radiation from the UVA range is rather weakly absorbed by the atmosphere. Therefore, the radiation that reaches the Earth's surface contains a large part of the near ultraviolet UVA and a small proportion of UVB.

Somewhat later, in the works (O. G. Gazenko, Yu. E. Nefedov, E. A. Shepelev, S. N. Zaloguev, N. E. Panferova, I. V. Anisimova), the specified specific effect of radiation was confirmed in space medicine . Prophylactic UV irradiation was introduced into the practice of space flights along with the Guidelines (MU) 1989 "Prophylactic ultraviolet irradiation of people (using artificial sources of UV radiation)". Both documents are a reliable basis for further improvement of UV prevention.

Skin exposure to ultraviolet radiation that exceeds the skin's natural protective ability to tan leads to burns.

Long-term exposure to ultraviolet radiation can contribute to the development of melanoma and premature aging.

Ultraviolet radiation is imperceptible to the human eye, but with intense exposure it causes a typical radiation injury (retinal burn).

natural springs

The main source of ultraviolet radiation on Earth is the Sun. The ratio of UV-A to UV-B radiation intensity, the total amount of ultraviolet rays reaching the Earth's surface, depends on the following factors:

on the concentration of atmospheric ozone above the earth's surface (see ozone holes)

from the height of the sun above the horizon

from height above sea level

from atmospheric dispersion

from cloud cover

on the degree of reflection of UV rays from the surface (water, soil)

Thanks to the creation and improvement of artificial sources of UV radiation, which went in parallel with the development of electric sources of visible light, today specialists working with UV radiation in medicine, preventive, sanitary and hygienic institutions, agriculture, etc., are provided with significantly greater opportunities than with using natural UV radiation.

There are a number of lasers operating in the ultraviolet region. The laser makes it possible to obtain coherent radiation of high intensity. However, the ultraviolet region is difficult for laser generation, so there are no sources as powerful here as in the visible and infrared ranges. Ultraviolet lasers find their application in mass spectrometry, laser microdissection, biotechnology and other scientific research.

Many polymers used in consumer products degrade when exposed to UV light. To prevent degradation, special substances capable of absorbing UV are added to such polymers, which is especially important when the product is exposed to direct sunlight. The problem manifests itself in the disappearance of color, tarnishing of the surface, cracking, and sometimes the complete destruction of the product itself. The rate of destruction increases with increasing exposure time and intensity of sunlight.

The described effect is known as UV aging and is one of the varieties of polymer aging. Sensitive polymers include thermoplastics such as polypropylene, polyethylene, polymethyl methacrylate (organic glass) as well as special fibers such as aramid fiber. UV absorption leads to the destruction of the polymer chain and loss of strength at a number of points in the structure. The action of UV on polymers is used in nanotechnologies, transplantation, X-ray lithography, and other fields to modify the properties (roughness, hydrophobicity) of the surface of polymers. For example, the smoothing effect of vacuum ultraviolet (VUV) on the surface of polymethyl methacrylate is known.

Applications: Ultraviolet (UV) disinfection, Air and hard surface sterilization, Drinking water disinfection, Chemical analysis, UV spectrometry, Mineral analysis, Qualitative chromatographic analysis, Insect trapping, Artificial tanning and "Mountain Sun", restoration.

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

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

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

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

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

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

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

Properties of UV radiation

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

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

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

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

History of the discovery of ultraviolet radiation

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

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

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

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

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

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

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

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

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

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

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

Properties of ultraviolet radiation photo

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Everyone knows that the Sun - the center of our planetary system and an aging star - emits rays. Solar radiation consists of ultraviolet rays (UV / UV) type A, or UVA - long wavelength, type B, or UVB - short wavelength. Our understanding of the types of damage they can cause to the skin and how best to protect against UV seems to change every year as new research emerges. For example, it was once thought that only UVBs were harmful to the skin, but we are learning more and more from research about the damage caused by UVA. As a result, improved forms of UVA protection are emerging that can, when applied correctly, prevent sun damage.

What is UV radiation?

UV radiation is part of the electromagnetic (light) spectrum that reaches the Earth from the Sun. The wavelength of UV radiation is shorter than the visible light spectrum, making it invisible to the naked eye. Radiation by wavelength is divided into UVA, UVB and UVC, with UVA being the longest wavelength (320-400 nm, where nm is a billionth of a meter). UVA is subdivided into two more wavelength ranges: UVA I (340-400 nm) and UVA II (320-340 nm). The UVB range is from 290 to 320 nm. The shorter UVC rays are absorbed by the ozone layer and do not reach the earth's surface.

However, two types of rays - UVA and UVB - penetrate the atmosphere and are the cause of many diseases - premature skin aging, eye damage (including cataracts) and skin cancer. They also suppress the immune system, reducing the body's ability to fight these and other diseases.

UV radiation and skin cancer

By damaging the skin's cellular DNA, excessive UV radiation causes genetic mutations that can lead to skin cancer. Therefore, both the US Department of Health and Human Services and the World Health Organization have recognized UV as a proven human carcinogen. UV radiation is considered the main cause of non-melanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). These cancers affect more than a million people worldwide each year, of which more than 250,000 are US citizens. Many experts believe that, especially for people with pale skin, UV radiation often plays a key role in the development of melanoma, the deadliest form of skin cancer that kills more than 8,000 Americans every year.

UV A radiation

Most of us are exposed to a lot of UV light throughout our lives. UVA rays account for up to 95% of the UV radiation that reaches the Earth's surface. Although they are less intense than UVB, UVA rays are 30 to 50 times more common. They are present with relatively equal intensity throughout the daylight hours throughout the year and can penetrate clouds and glass.

It is UVA, which penetrates the skin more deeply than UVB, that is to blame for skin aging and wrinkling (so-called solar geroderma), but until recently, scientists believed that UVA did not cause significant damage to the epidermis (the outermost layer of the skin), where most cases of skin cancer. However, studies over the past two decades show that it is UVA that damages skin cells called keratinocytes in the basal layer of the epidermis, where most skin cancers develop. Basal and squamous cells are types of keratinocytes.

UVA is also the main cause of tanning, and we now know that tanning (whether outdoors or in a tanning bed) causes damage to the skin that gets worse over time as the skin's DNA gets damaged. It turns out that the skin darkens precisely because in this way the body tries to prevent further DNA damage. These mutations can lead to skin cancer.

An upright tanning bed mainly emits UVA. The lamps used in tanning salons emit 12 times more UVA than the sun. Not surprisingly, people who use a tanning salon are 2.5 times more likely to develop squamous cell carcinoma and 1.5 times more likely to develop basal cell carcinoma. According to recent studies, first exposure to a tanning bed at a young age increases the risk of melanoma by 75%.

UV B radiation

UVB, which are the main cause of skin redness and sunburn, mainly damages the more superficial epidermal layers of the skin. UVB plays a key role in the development of skin cancer, aging and skin darkening. The intensity of radiation depends on the season, location and time of day. The most significant amount of UVB hits the US between 10:00 am and 4:00 pm from April to October. However, UVB rays can damage the skin all year round, especially at high altitudes and on reflective surfaces such as snow or ice, which bounce back up to 80% of the rays so that they hit the skin twice. The only good news is that UVB practically does not penetrate glass.

Protective measures

Remember to protect yourself from UV radiation both indoors and outdoors. Always look for shade outside, especially between 10:00 and 16:00. And since UVA penetrates glass, consider adding a tinted UV protection film to the top of your car's side and rear windows, as well as your home and office windows. This film blocks up to 99.9% of UV radiation and transmits up to 80% of visible light.

When outdoors, wear sun protection clothing with UPF (Ultra Violet Protection Factor) to limit UV exposure. The higher the UPF values, the better. For example, a shirt with UPF 30 means that only 1/30th of the sun's ultraviolet radiation can reach the skin. There are special additives in laundry detergents that provide higher UPF values ​​in ordinary fabrics. Do not ignore the opportunity to protect yourself - choose those fabrics that have the best protection from the sun's rays. For example, bright or dark shiny clothes reflect more UV radiation than light and bleached cotton fabrics; however, loose clothing provides a greater barrier between your skin and the sun's rays. Finally, wide-brimmed hats and UV-protective sunglasses help protect the sensitive skin on the forehead, neck, and around the eyes—these areas typically suffer the most damage.

Protective Factor (SPF) and UV B radiation

With the advent of modern sunscreens, it has become a tradition to measure their effectiveness with the sun protection factor, or SPF. Oddly enough, SPF is not a factor or a measure of protection as such.

These numbers simply indicate how long it takes for UVB rays to redden the skin when using sunscreen compared to how long the skin would redden without the product. For example, using sunscreen with SPF 15, a person will prolong the time of safe exposure to the sun by 15 times compared to exposure in similar conditions without sunscreen. Sunscreen SPF 15 blocks 93% of the sun's UVB rays; SPF 30 - 97%; and SPF 50 - up to 98%. A cream with an SPF of 15 or even higher is essential for adequate day-to-day skin protection during the sunny season. For longer or more intense sun exposure, such as being at the beach, SPF 30 or higher is recommended.

sunscreen component

Since UVA and UVB are harmful to the skin, protection from both types of rays is essential. Effective protection starts with an SPF of 15 or higher, and the following ingredients are also important: stabilized avobenzone, ecamsule ( also known as MexorylTM), oxybenzone, titanium dioxide, And zinc oxide. On sunscreen labels, phrases like “multiple spectrum protection”, “broad spectrum protection”, or “UVA/UVB protection” all indicate that UVA protection is provided. However, such phrases may not be entirely true.

There are currently 17 active ingredients approved by the FDA (Food and Drug Administration) for use in sunscreens. These filters fall into two broad categories: chemical and physical. Most UV filters are chemical, meaning they form a thin protective film on the surface of the skin and absorb UV radiation before the rays penetrate the skin. Physical sunscreens most often consist of insoluble particles that reflect UV rays away from the skin. Most sunscreens contain a mixture of chemical and physical filters.

• Look for shade, especially between 10:00 and 16:00.
• Don't get burned.
• Avoid intense tanning and vertical tanning beds.
• Wear covered clothing, including a wide-brimmed hat and UV-blocking sunglasses.
• Use a broad spectrum (UVA/UVB) sunscreen with an SPF of 15 or higher every day. For prolonged outdoor activity, use a waterproof, broad-spectrum (UVA/UVB) sunscreen with an SPF of 30 or higher.
• Apply a generous amount (2 tablespoons minimum) of sunscreen all over your body 30 minutes before going outside. Reapply the cream every two hours or immediately after swimming/excessive sweating.
• Keep newborns out of the sun, as sunscreen can only be used on babies over six months old.
• Every month, check your skin from head to toe - if you find something suspicious, then run to the doctor.
• See your doctor for a professional skin exam annually.

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

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

Today it is divided into three groups:

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

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

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

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

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

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

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

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

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

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

Germicidal installations

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

Disadvantages of ultraviolet air disinfection

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

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

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

UV radiation is electromagnetic waves that are invisible to the human eye. It occupies a spectral position between visible and X-ray radiation. The interval of ultraviolet radiation is usually divided into near, medium and far (vacuum).

Biologists have made such a division of UFL in order to better see the difference in the effect of rays of different lengths on a person.

• Near ultraviolet is commonly referred to as UV-A.
• medium - UV-B,
• far - UV-C.

Ultraviolet radiation comes from the sun and The atmosphere of our planet Earth protects us from the powerful effects of ultraviolet rays.. The sun is one of the few natural UV emitters. At the same time, far ultraviolet UV-C is almost completely blocked by the Earth's atmosphere. Those 10% of long-wave ultraviolet rays reach us in the form of the sun. Accordingly, the ultraviolet that hits the planet is mainly UV-A, and in small amounts UV-B.

One of the main properties of ultraviolet is its chemical activity, due to which UV radiation has great impact on the human body. The most dangerous for our body is short-wave ultraviolet. Despite the fact that our planet protects us as much as possible from exposure to ultraviolet rays, if you do not follow some precautions, you can still suffer from them. Sources of the short-wave type of radiation are welding machines and ultraviolet lamps.

Positive properties of ultraviolet

It was only in the 20th century that studies began to be carried out that proved positive effect of UV radiation on the human body. The result of these studies was the identification of the following beneficial properties: strengthening human immunity, activating protective mechanisms, improving blood circulation, dilating blood vessels, increasing vascular permeability, and increasing the secretion of a number of hormones.

Another property of ultraviolet light is its ability to change carbohydrate and protein metabolism human substances. UV rays can also affect the ventilation of the lungs - the frequency and rhythm of breathing, increased gas exchange, and the level of oxygen consumption. The functioning of the endocrine system also improves, vitamin D is formed in the body, which strengthens the human musculoskeletal system.

The use of ultraviolet in medicine

Ultraviolet light is often used in medicine. While ultraviolet rays can be harmful to the human body in some cases, they can be beneficial if used properly.

In medical institutions, a useful application of artificial ultraviolet has long been invented. There are various emitters that can help a person with the help of ultraviolet rays. cope with various diseases. They are also divided into those that emit long, medium and short waves. Each of them is used in a specific case. So, long-wave radiation is suitable for the treatment of the respiratory tract, for damage to the bone and joint apparatus, as well as in case of various skin injuries. We can also see long-wave radiation in solariums.

Treatment performs a slightly different function medium wave ultraviolet. It is prescribed mainly to people suffering from immunodeficiency, metabolic disorders. It is also used in the treatment of disorders of the musculoskeletal system, has an analgesic effect.

shortwave radiation it is also used in the treatment of skin diseases, diseases of the ears, nose, respiratory tract injuries, diabetes mellitus, and damage to the heart valves.

In addition to various devices that emit artificial ultraviolet radiation, which are used in mass medicine, there are also ultraviolet lasers, which have a more precise action. These lasers are used, for example, in eye microsurgery. Such lasers are also used for scientific research.

The use of ultraviolet in other areas

In addition to medicine, ultraviolet radiation is used in many other areas, significantly improving our lives. So, ultraviolet is great disinfectant, and is used, among other things, for the treatment of various objects, water, indoor air. Widely used ultraviolet and in printing: it is with the help of ultraviolet that various seals and stamps are produced, paints and varnishes are dried, banknotes are protected from counterfeiting. In addition to its useful properties, when properly applied, ultraviolet can create beauty: it is used for various lighting effects (most often this happens in discos and performances). UV rays also help in finding fires.

One of the negative consequences of ultraviolet exposure to the human body is electrophthalmia. This term is called a lesion of the human organ of vision, in which the cornea of ​​​​the eye is burned and swells, and a cutting pain appears in the eyes. This disease can occur if a person looks at the rays of the sun without a special protective device (sunglasses) or stays in a snowy area in sunny weather, with very bright light. Also, electrophthalmia can be earned by quartzing the premises.

Negative effects can also be achieved due to the long, intense exposure to ultraviolet rays on the body. There can be quite a lot of such consequences, up to the development of various pathologies. The main symptoms of overexposure are

The consequences of strong exposure are as follows: hypercalcemia, growth retardation, hemolysis, impaired immunity, various burns and skin diseases. The most susceptible to excessive exposure are people who constantly work outdoors, as well as those people who constantly work with devices that emit artificial ultraviolet radiation.

Unlike UV emitters used in medicine, tanning beds are more dangerous for a person. Visiting solariums is not controlled by anyone, except for the person himself. People who frequent tanning salons in order to achieve a beautiful tan often neglect the negative effects of UV radiation, despite the fact that frequent visits to tanning beds can even be fatal.

The acquisition of a darker skin color occurs due to the fact that our body fights against the traumatic effects of UV radiation on it, and produces a coloring pigment called melanin. And if redness of the skin is a temporary defect that passes after some time, then freckles appearing on the body, age spots that occur as a result of the growth of epithelial cells - permanent skin damage.

Ultraviolet, penetrating deeply into the skin, can change skin cells at the gene level and lead to ultraviolet mutagenesis. One of the complications of this mutagenesis is melanoma, a skin tumor. It is she who can lead a person to death.

To avoid the negative effects of UV exposure, need some protection. At various enterprises working with devices emitting artificial ultraviolet, it is necessary to use overalls, helmets, shields, insulating screens, goggles, and a portable screen. People who are not involved in the activities of such enterprises should limit themselves to excessive visits to solariums and prolonged exposure to the open sun, use sunscreens, sprays or lotions in the summer, and wear sunglasses and closed clothing made from natural fabrics.

There are also negative effects from lack of UV radiation. Prolonged absence of UV radiation can lead to a disease called "light starvation". Its main symptoms are very similar to those of excessive UV exposure. With this disease, a person's immunity decreases, metabolism is disturbed, fatigue, irritability, etc. appear.