UV radiation is electromagnetic waves, which are invisible to the human eye. It occupies a spectral position between visible and X-ray radiation. Interval ultraviolet radiation It is customary to divide into near, middle and far (vacuum).
Biologists made such a division of UV rays so that they could better see the difference in the effect of rays of different lengths on a person.
- Near ultraviolet is commonly called UV-A.
- medium - UV-B,
- far - UV-C.
Ultraviolet radiation comes from the sun and the atmosphere of our planet Earth protects us from powerful impact ultraviolet rays. The sun is one of the few natural UV emitters. At the same time, far-ultraviolet UV-C is blocked almost completely by the Earth's atmosphere. Those 10% of long-wave ultraviolet rays reach us in the form of the sun. Accordingly, the ultraviolet that reaches the planet is mainly UV-A, and in small quantities UV-B.
One of the main properties of ultraviolet radiation is its chemical activity, due to which UV radiation has great influence on the human body. Short-wave ultraviolet radiation is considered the most dangerous for our body. Despite the fact that our planet protects us as much as possible from exposure to ultraviolet rays, if you do not take certain precautions, you can still suffer from them. Sources of short-wave radiation are welders And ultraviolet lamps.
Positive properties of ultraviolet light
Only in the 20th century did research begin to prove positive influence UV radiation on the human body. The result of these studies was the identification of the following useful properties: strengthening human immunity, activating protective mechanisms, improving blood circulation, dilating blood vessels, increasing vascular permeability, increasing the secretion of a number of hormones.
Another property of ultraviolet light is its ability change carbohydrate and protein metabolism human substances. UV rays can also affect ventilation of the lungs - the frequency and rhythm of breathing, increasing 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.
Application of ultraviolet radiation in medicine
Quite often, ultraviolet light is used in medicine. Although ultraviolet rays can be harmful to the human body in some cases, they can also be beneficial when used correctly.
Medical institutions have long ago invented useful application artificial ultraviolet light. There are various emitters that can help a person using 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. Thus, long-wave radiation is suitable for treating the respiratory tract, for damage to the osteoarticular apparatus, as well as in the case of various skin injuries. We can also see long-wave radiation in solariums.
Treatment performs a slightly different function mid-wave ultraviolet. It is prescribed mainly to people suffering from immunodeficiency and metabolic disorders. It is also used in the treatment of musculoskeletal disorders and has an analgesic effect.
Shortwave radiation It is also used in the treatment of skin diseases, diseases of the ears, nose, damage to the respiratory tract, diabetes, and damage to the heart valves.
In addition to various devices emitting artificial ultraviolet light, which are used in mass medicine, there are also ultraviolet lasers, having a more targeted effect. These lasers are used, for example, in eye microsurgery. Such lasers are also used for scientific research.
Application of ultraviolet radiation in other areas
In addition to medicine, ultraviolet radiation is used in many other areas, significantly improving our lives. So, ultraviolet is excellent disinfectant, and is used, among other things, for treating various objects, water, and indoor air. Ultraviolet light is widely used and in printing: It is with the help of ultraviolet that various seals and stamps are produced, paints and varnishes are dried, and banknotes are protected from counterfeiting. In addition to its beneficial properties, when applied correctly, ultraviolet light can create beauty: it is used for various lighting effects (most often this happens at discos and performances). UV rays also help in finding fires.
One of the negative consequences of ultraviolet exposure on the human body is electroophthalmia. This term refers to damage to the human organ of vision, in which the cornea of the eye burns 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 special protective equipment (sunglasses) or stays in a snowy area in sunny weather with very bright light. Electroophthalmia can also be caused by quartzing premises.
Negative consequences can also be achieved due to long, intense exposure to ultraviolet rays on the body. There can be quite a lot of such consequences, including the development of various pathologies. The main symptoms of overexposure are
The consequences of strong radiation are the following: hypercalcemia, growth retardation, hemolysis, deterioration of immunity, various burns and skin diseases. People who constantly work at work are most susceptible to excessive exposure. outdoors, as well as those people who constantly work with devices that emit artificial ultraviolet light.
Unlike UV emitters used in medicine, tanning salons are more dangerous for a person. Visits to solariums are not controlled by anyone other than the person himself. People who often visit solariums in order to achieve a beautiful tan often neglect the negative effects of UV radiation, despite the fact that frequent visits to solariums can even lead to death.
The acquisition of darker skin color occurs due to the fact that our body fights 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 goes away after some time, then freckles and age spots that appear on the body, which occur as a result of the proliferation of epithelial cells - permanent skin damage.
Ultraviolet light penetrating deeply into skin, can change skin cells at the genetic level and lead to ultraviolet mutagenesis. One of the complications of this mutagenesis is melanoma, a skin tumor. It is this that can lead to death.
To avoid the negative effects of exposure to UV rays, you need to provide yourself with some protection. At various enterprises working with devices that emit artificial ultraviolet radiation, it is necessary to use special clothing, helmets, shields, insulating screens, safety glasses, and a portable screen. People who are not involved in the activities of such enterprises need to limit themselves from excessive visits to solariums and prolonged exposure to the open sun, in the summer, use sunscreens, sprays or lotions, and also wear sunglasses and closed clothing made from natural fabrics.
There are also Negative consequences from lack of UV radiation. Long-term absence of UVR can lead to a disease called “light starvation.” Its main symptoms are very similar to those of excessive exposure to ultraviolet radiation. With this disease, a person’s immunity decreases, metabolism is disrupted, fatigue, irritability, etc. appear.
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 what types of damage they can cause to the skin and how best to protect ourselves from UV seems to change every year as new research comes to light. For example, it was once believed that only UVB was harmful to the skin, but we are learning more and more from research about damage caused by UVA. As a result, improved forms of UVA protection are emerging that can correct use prevent damage from sun exposure.
What is UV radiation?
UV radiation is part of the electromagnetic (light) spectrum that reaches the Earth from the Sun. UV radiation has wavelengths shorter than the spectrum of visible light, 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 further divided into two wavebands: UVA I (340-400 nm) and UVA II (320-340 nm). The UVB range is from 290 to 320 nm. Shorter UVC rays are absorbed ozone layer and do not reach the surface of the earth.
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 work 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. Ultraviolet radiation is considered a major cause of nonmelanoma skin cancers (NMSCs), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). These cancers affect more than a million people worldwide each year, of whom more than 250,000 are U.S. 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 each year.
UV A radiation
Most of us are exposed to large amounts of ultraviolet radiation throughout our lives. UVA rays make up 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 prevalent. They are present at relatively equal intensity throughout 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 wrinkles (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 it is localized. most cases of skin cancer. However, research over the past two decades shows that it is UVA that damages skin cells called keratinocytes in the basal layer of the epidermis, where most skin cancers develop. Basal cells and squamous cells are types of keratinocytes.
It's also UVA that causes tanning, and we now know that tanning (whether it's done outdoors or in a tanning bed) causes damage to the skin that gets worse over time as it damages the skin's DNA. It turns out that the skin darkens precisely because the body is trying to prevent further DNA damage. These mutations can lead to skin cancer.
A vertical tanning bed primarily emits UVA. Lamps used in tanning salons emit UVA doses 12 times higher 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 tanning beds at a young age increases the risk of melanoma by 75%.
UVB radiation
UVB, which are main reason skin redness and sunburn, cause mainly damage to the more superficial epidermal layers of the skin. UVB plays a key role in the development of skin cancer, aging and darkening of the skin. The intensity of radiation depends on the season, location and time of day. The most significant amounts of UVB affect the United States between 10:00 a.m. and 4:00 p.m. 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 up to 80% of the rays back so they hit the skin twice. The only good thing 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 tinted UV protective film to upper parts side and rear windows of your car, as well as on the windows of your home and office. 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 (ultraviolet protection factor) to limit your exposure to UV radiation. The higher the UPF values, the better. For example, a shirt with a UPF of 30 means that only 1/30th of the sun's ultraviolet radiation can reach the skin. There are also special additives in laundry detergents that provide more high values UPF. Don’t ignore the opportunity to protect yourself - choose those fabrics that have best protection from the sun's rays. For example, bright or dark shiny clothing reflects 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 sunglasses with UV protection help protect the sensitive skin on the forehead, neck, and around the eyes—these areas tend to experience the most severe damage.
Protective factor (SPF) and UVB radiation
With the advent of modern sunscreens, there has been a tradition of measuring their effectiveness by 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 will take for UVB rays to cause your skin to turn red when using sunscreen, compared to how long your skin will turn red without using the product. For example, using sunscreen with SPF 15, a person will extend the time of safe sun exposure by 15 times compared to staying 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 SPF 15 or even higher is necessary for adequate everyday skin protection in solar time of the year. For longer or more intense sun exposure, such as at the beach, an SPF of 30 or higher is recommended.
Sun protection component
Since UVA and UVB are harmful to the skin, you need protection from both types of rays. Effective protection starts with an SPF of 15 or higher, and the following ingredients are also important: stabilized avobenzone, ecamsule ( also known as Mexoryl TM), oxybenzone, titanium dioxide, And zinc oxide. On sunscreen labels you may read phrases like “multiple-spectrum protection,” “broad-spectrum protection,” or “UVA/UVB protection,” all of which indicate that UVA protection is provided. However, such phrases may not entirely correspond to reality.
There are currently 17 active ingredients approved by the FDA. medicines) 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.
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Sunscreens approvedFDA |
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Name of active ingredient/UV filter |
Coverage Range |
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UVA1: 340-400 nm |
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UVA2: 320-340 nm |
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Chemical absorbents: |
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Aminobenzoic acid (PABA) |
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Ecamsule (Mexoryl SX) |
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Ensulizole (Phenylbenzimiazole Sulfonic Acid) |
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Meradimate (Menthyl Anthranilate) |
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Octinoxate (Octyl Methoxycinnamate) |
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Octisalate (Octyl Salicylate) |
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Trolamine Salicylate |
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Physical filters: |
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Titanium Dioxide |
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- Look for shade, especially between 10 a.m. and 4 p.m.
- Don't get burned.
- Avoid intense tanning and vertical solariums.
- Wear covered clothing, including a wide-brimmed hat and sunglasses with UV filters.
- Use a broad-spectrum (UVA/UVB) sunscreen with SPF 15 or higher every day. For prolonged outdoor activities, use a water-resistant broad-spectrum (UVA/UVB) sunscreen with SPF 30 or higher.
- Apply an ample amount (2 tablespoons minimum) of sunscreen to your entire body 30 minutes before going outside. Reapply the cream every two hours or immediately after swimming/excessive sweating.
- Protect newborns from the sun, as sunscreens should only be used on infants over six months of age.
- Every month check your skin from head to toe - if you find something suspicious, then run to the doctor.
- Visit your doctor annually for a professional skin examination.
In agricultural production, for the technological impact of optical radiation on living organisms and plants, special sources of ultraviolet (100...380 nm) and infrared (780...106 nm) radiation, as well as sources of photosynthetically active radiation (400...700 nm) are widely used.
According to the distribution of optical radiation flux between different areas ultraviolet spectrum There are sources of general ultraviolet (100...380 nm), vital (280...315 nm) and predominantly bactericidal (100...280 nm) effects.
Sources of general ultraviolet radiation- mercury arc tube lamps high pressure DRT type (mercury-quartz lamps). A DRT lamp is a quartz glass tube with tungsten electrodes soldered into the ends. A dosed amount of mercury and argon is introduced into the lamp. For ease of fastening to the fittings, DRT lamps are equipped with metal holders. DRT lamps are available with a power of 2330, 400, 1000 W.
Vital fluorescent lamps of the LE type are made in the form of cylindrical tubes made of uviol glass, the inner surface of which is covered with a thin layer of phosphor, emitting a light flux in the ultraviolet region of the spectrum with a wavelength of 280...380 nm (maximum radiation in the region of 310...320 nm). Apart from the type of glass, tube diameter and phosphor composition, tubular vital lamps are structurally no different from tubular low-pressure fluorescent lamps and are connected to the network using the same devices (throttle and starter) as fluorescent lamps of the same power. LE lamps are available in 15 and 20 W outputs. In addition, vital lighting fluorescent lamps have been developed.
Germicidal lamps- these are sources of short-wave ultraviolet radiation, most of which (up to 80%) occurs at a wavelength of 254 nm. Design bactericidal lamps is not fundamentally different from tubular low-pressure fluorescent lamps, but the glass with alloying additives used for their manufacture transmits radiation well in the spectral range less than 380 nm. In addition, the bulb of bactericidal lamps is not coated with phosphor and has slightly reduced dimensions (diameter and length) compared to similar general-purpose fluorescent lamps of the same power.
Germicidal lamps are connected to the network using the same devices as fluorescent lamps.
Lamps with increased photosynthetically active radiation. These lamps are used for artificial irradiation of plants. These include low-pressure fluorescent photosynthetic lamps of the LF and LFR types (P means reflector), high-pressure mercury arc fluorescent photosynthetic lamps of the DRLF type, high-pressure metal halide mercury arc lamps of the DRF, DRI, DROT, DMC types, and tungsten arc mercury lamps of the DRV type.
Low-pressure fluorescent photosynthetic lamps of the LF and LFR types are similar in design to low-pressure fluorescent lamps and differ from them only in the composition of the phosphor, and, consequently, in the emission spectrum. In LF type lamps, the relatively high radiation density lies in the wave ranges of 400...450 and 600...700 nm, which account for the maximum spectral sensitivity of green plants.
DRLF lamps are structurally similar to DRL type lamps, but unlike the latter, they have increased radiation in the red part of the spectrum. Under the phosphor layer, DRLF lamps have a reflective coating that ensures the required distribution of the radiant flux in space.
In the simplest case, the source of infrared radiation can be an ordinary incandescent lighting lamp. In its emission spectrum, the infrared region occupies almost 75%, and the flow of infrared rays can be increased by reducing the voltage supplied to the lamp by 10...15% or by painting the bulb blue or red. However, the main source of infrared radiation is special infrared reflector lamps.
Infrared mirror lamps(thermal emitters) differ from conventional lighting lamps in the paraboloid shape of the bulb and the lower temperature of the filament. Regarding low temperature The incandescent filament of thermal emitter lamps makes it possible to shift the spectrum of their radiation to the infrared region and increase the average burning time to 5000 hours.
The inner part of the bulb of such lamps, adjacent to the base, is covered with a mirror layer, which allows the emitted infrared flux to be redistributed and concentrated in a given direction. To reduce the intensity of visible radiation, the lower part of the bulb of some infrared lamps is coated with red or blue heat-resistant varnish.
Ultraviolet radiation (ultraviolet, UV, UV) - electromagnetic radiation occupying the range between the violet boundary visible radiation and X-ray radiation (380 - 10 nm, 7.9·1014 - 3·1016 Hertz).
The concept of ultraviolet rays was first encountered by an Indian philosopher of the 13th century in his work. The atmosphere of the Bhootakasha area he described contained violet rays that cannot be seen with the naked eye.
Soon after infrared radiation was discovered, the German physicist Johann Wilhelm Ritter began searching 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 faster when exposed to light decomposes when exposed to invisible radiation outside the violet region of the spectrum. Silver chloride white within a few minutes it darkens in the light. Different parts of the spectrum have different effects on the rate of darkening. This happens most quickly in front of the violet region of the spectrum. Many scientists, including Ritter, then agreed that light consists of three distinct components: an oxidative or thermal (infrared) component, an illuminant (visible light) component, and a reducing (ultraviolet) component. At that time, ultraviolet radiation was also called actinic radiation. Ideas about the unity of 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 various ways. The ISO standard for the definition of solar radiation (ISO-DIS-21348) gives the following definitions:
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Name |
Abbreviation |
Wavelength in nanometers |
Amount of energy per photon |
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Near |
400 nm - 300 nm |
3.10 - 4.13 eV |
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Average |
300 nm - 200 nm |
4.13 - 6.20 eV |
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Further |
200 nm - 122 nm |
6.20 - 10.2 eV |
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Extreme |
121 nm - 10 nm |
10.2 - 124 eV |
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Ultraviolet A, long wave range |
400 nm - 315 nm |
3.10 - 3.94 eV |
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Ultraviolet B, midwave |
315 nm - 280 nm |
3.94 - 4.43 eV |
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Ultraviolet C, shortwave |
280 nm - 100 nm |
4.43 - 12.4 eV |
The near ultraviolet range is often called “black light” because it is not recognized by the human eye, but when reflected from some materials, the spectrum moves into the visible region.
For the far and extreme range, the term "vacuum" (VUV) is often used, 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 identify 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, 100-280 nm)
Almost all UVC and approximately 90% of UVB are absorbed by ozone, as well as water vapor, oxygen and carbon dioxide when passing sunlight through the earth's atmosphere. Radiation from the UVA range is rather weakly absorbed by the atmosphere. Therefore, the radiation reaching the Earth's surface largely contains near-ultraviolet UVA and a small proportion - UVB.
Somewhat later, in the works of (O. G. Gazenko, Yu. E. Nefedov, E. A. Shepelev, S. N. Zaloguev, N. E. Panferova, I. V. Anisimova), this specific effect of radiation was confirmed in space medicine . Preventive UV irradiation was introduced into space flight practice along with the 1989 Methodological Instructions (MU) “Preventive ultraviolet irradiation of people (using artificial sources of UV radiation).” Both documents are a reliable basis for further improvement of UV prevention.
Exposure of the skin to ultraviolet radiation in excess of the skin's natural protective ability to tan results in 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 irradiation it causes typical radiation damage (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 altitude above sea level
from atmospheric dispersion
on the state of the 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 electrical sources of visible light, today specialists working with UV radiation in medicine, preventive, sanitary and hygienic institutions, agriculture, etc., are provided with significantly great opportunities than when using natural UV radiation.
There are a number of lasers operating in the ultraviolet region. The laser produces high-intensity coherent radiation. However, the ultraviolet region is difficult for laser generation, so there are no sources as powerful as in the visible and infrared ranges. Ultraviolet lasers are used 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 that can absorb UV are added to such polymers, which is especially important in cases where the product is directly exposed to sunlight. The problem manifests itself in color fading, surface tarnishing, cracking, and sometimes complete destruction of the product itself. The rate of destruction increases with increasing exposure time and sunlight intensity.
The described effect is known as UV aging and is one of the types of aging of polymers. Sensitive polymers include thermoplastics such as polypropylene, polyethylene, polymethyl methacrylate (plexiglass), as well as special fibers such as aramid fiber. UV absorption leads to destruction of the polymer chain and loss of strength at a number of points in the structure. The effect of UV on polymers is used in nanotechnology, transplantology, X-ray lithography and other fields to modify the properties (roughness, hydrophobicity) of the polymer surface. For example, the smoothing effect of vacuum ultraviolet (VUV) on the surface of polymethyl methacrylate is known.
Application: Ultraviolet (UV) radiation disinfection, Sterilization of air and hard surfaces, Disinfection of drinking water, Chemical analysis, UV spectrometry, Mineral analysis, Qualitative chromatographic analysis, Insect fishing, Artificial tanning and “Mountain sun”, restoration.
Ultraviolet radiation is a form of optical radiation not visible to the human eye, characterized by shorter length and higher energy photons compared to light. Ultraviolet rays span the spectrum between visible and x-ray radiation, in the wavelength range 400-10 nm. In this case, the radiation region in the range of 200-10 nm is called far or vacuum, and the region in the range of 400-200 nm is called near.
UV sources
1 Natural sources(stars, sun, etc.)
Only the long-wave part of ultraviolet radiation from space objects (290-400 nm) is capable of reaching the Earth's surface. At the same time, short-wave radiation is completely absorbed by oxygen and other substances in the atmosphere at an altitude of 30-200 km from the earth's surface. UV radiation from stars in the wavelength range 90-20 nm is almost completely absorbed.
2. Artificial sources
Radiation solids, heated to a temperature of 3 thousand kelvins includes a certain proportion of UV radiation, the intensity of which increases noticeably with increasing temperature.
A powerful source of UV radiation is gas-discharge plasma.
IN various industries production (food, chemical and other industries) and medicine use gas-discharge, xenon, mercury-quartz and other lamps, the cylinders of which are made of transparent materials - usually quartz. Significant UV radiation is emitted by electrons in the accelerator and special lasers in the nickel-like ion.
Basic properties of ultraviolet radiation
The practical use of ultraviolet is due to its basic properties:
— significant chemical activity (helps accelerate the flow of chemical and biological processes);
- bactericidal effect;
- the ability to cause luminescence of substances - glow with different colors of emitted light.
Studying emission/absorption/reflection spectra in the UV range using modern equipment makes it possible to establish the electronic structure of atoms, molecules, and ions.
UV spectra of the Sun, stars and various nebulae make it possible to obtain reliable information about the processes occurring in these objects.
Also, ultraviolet radiation can disrupt and change chemical bonds in molecules, as a result, can occur various reactions(reduction, oxidation, polymerization, etc.), which serves as the basis for such a science as photochemistry.
UV radiation can destroy bacteria and microorganisms. Thus, ultraviolet lamps are widely used for disinfection in public places (medical institutions, kindergartens, subways, train stations, etc.).
Certain doses of UV radiation contribute to the formation of vitamin D, serotonin and other substances on the surface of human skin that affect the tone and activity of the body. Excessive exposure to ultraviolet radiation leads to burns and accelerates the aging process of the skin.
Ultraviolet radiation is also actively used in the cultural and entertainment sphere - to create a series of unique lighting effects in discos, stages of bars, theaters, etc.