UV exposure. Using the bactericidal properties of ultraviolet radiation. Properties of ultraviolet radiation photo

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 against UV seems to change every year as new research emerges. For example, it was once believed 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 work immune system, reducing the body's ability to fight these and other diseases.

UV radiation and skin cancer

By damaging the cellular DNA of the skin, excessive UV radiation causes genetic mutations which can lead to skin cancer. Therefore, both the US Department of Health and Human Services and World Organization The health authorities have recognized UV as a proven human carcinogen. Ultraviolet radiation is considered a major 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 a large number ultraviolet throughout life. 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 most outer layer skin), where most cases of skin cancer are localized. 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, the first exposure to a solarium in young age increases the risk of melanoma by 75%.

UV B 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 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 on high altitudes and on reflective surfaces such as snow or ice, which reflect 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 reinforcing a tinted UV protective film on the 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 protective clothing with UPF (protection factor) to limit UV exposure. ultraviolet radiation). 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 against sun rays. For example, bright or dark shiny clothes reflect more UV radiation than light and bleached cotton fabrics; True, loose clothing provides 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 and not a measure of protection as such.

These numbers simply indicate how long it takes for UVB rays to redden the skin with 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 daily skin protection in solar time of the year. 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 included. However, such phrases may not be entirely true.

There are currently 17 active ingredients approved by the FDA (Food and Drug Administration). 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.

Sunscreens approvedFDA
Name of active ingredient / UV filter	Coverage range
	UVA1: 340-400nm
	UVA2: 320-340nm
Chemical absorbents:
Aminobenzoic acid (PABA)
Ecamsule (Mexoryl SX)
Ensulizole (Phenylbenzimiazole Sulfonic Acid)
Meradimate (Menthyl Anthranilate)
Octinoxate (Octyl Methoxycinnamate)
Octisalate (Octyl Salicylate)
Trolamine Salicylate
Physical filters:
Titanium Dioxide

• 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 SPF 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 sunscreens Can only be used on infants 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.

Ultraviolet radiation is electromagnetic waves with a length of 180 to 400 nm. This physical factor has many positive effects on the human body and is successfully used to treat a number of diseases. We will talk about what these effects are, about indications and contraindications for the use of ultraviolet radiation, as well as about the devices used and methods of carrying out procedures in this article.

Ultraviolet rays penetrate the skin to a depth of 1 mm and cause many biochemical changes in it. There are long-wave (region A - the wavelength is from 320 to 400 nm), medium-wave (region B - the wavelength is 275-320 nm) and short-wave (region C - the wavelength is in the range from 180 to 275 nm) ultraviolet radiation. It is worth noting that different types radiation (A, B or C) affects the body in different ways, and therefore they should be considered separately.

longwave radiation

One of the main effects of this type of radiation is pigmenting: getting on the skin, the rays stimulate the appearance of certain chemical reactions resulting in the formation of melanin pigment. Granules of this substance are secreted into the skin cells and cause its tan. The maximum amount of melanin in the skin is determined after 48-72 hours from the moment of exposure.

The second important effect this method physiotherapy is immunostimulating: photodegradation products bind to skin proteins and induce a chain of biochemical transformations in cells. The result of this is the formation of an immune response after 1-2 days, that is, local immunity and non-specific resistance of the body to a variety of adverse environmental factors increase.

The third effect of ultraviolet radiation is photosensitizing. A number of substances have the ability to increase the sensitivity of the skin of patients to the effects of this type of radiation and stimulate the formation of melanin. That is, taking such a drug and subsequent ultraviolet irradiation will lead to swelling of the skin and its redness (the appearance of erythema) in people suffering from dermatological diseases. The result of the course of such treatment will be the normalization of pigmentation and skin structure. This method of treatment is called "photochemotherapy".

Of the negative effects of excessive long-wave ultraviolet irradiation, it is important to mention the inhibition of antitumor reactions, that is, an increase in the likelihood of developing a tumor process, in particular, melanoma - skin cancer.

Indications and contraindications

Indications for treatment with ultraviolet long-wave radiation are:

• chronic inflammatory processes in the respiratory system;
• diseases of the osteoarticular apparatus of an inflammatory nature;
• frostbite;
• burns;
• skin diseases - psoriasis, mycosis fungoides, vitiligo, seborrhea and others;
• wounds that are difficult to treat;
• trophic ulcers.

For some diseases, the use of this method of physiotherapy is not recommended. Contraindications are:

• acute inflammatory processes in the body;
• severe chronic renal and hepatic insufficiency;
• individual hypersensitivity to ultraviolet radiation.

Devices

Sources of UV rays are divided into integrated and selective. Integral ones emit UV rays of all three spectra, while selective ones emit only the A region or the B + C regions. As a rule, selective radiation is used in medicine, which is obtained using a LUV-153 lamp in irradiators UUD-1 and 1A, OUG-1 (for the head), OUK-1 (for the limbs), EGD-5, EOD-10, PUVA , Psorymox and others. Also, long-wave UV radiation is used in solariums designed to obtain a uniform tan.

This type of radiation can affect the whole body at once or any part of it.

If the patient is to undergo general exposure, he should undress and sit quietly for 5-10 minutes. Creams or ointments should not be applied to the skin. The whole body is exposed at once or its parts in turn - it depends on the type of installation.

The patient is at a distance of at least 12-15 cm from the apparatus, and his eyes are protected by special glasses. The duration of irradiation directly depends on the type of skin pigmentation - there is a table with irradiation schemes depending on this indicator. The minimum exposure time is 15 minutes, and the maximum is half an hour.

Medium wave ultraviolet radiation

This type of UV radiation has the following effects on the human body:

• immunomodulatory (in suberythemal doses);
• vitamin-forming (promotes the formation of vitamin D 3 in the body, improves the absorption of vitamin C, optimizes the synthesis of vitamin A, stimulates metabolism);
• anesthetic;
• anti-inflammatory;
• desensitizing (the body's sensitivity to protein photodegradation products decreases - in erythemal doses);
• trophostimulating (stimulates a number of biochemical processes in cells, as a result of which the number of functioning capillaries and arterioles increases, blood flow in tissues improves - erythema forms).

Indications and contraindications

Indications for the use of medium-wave ultraviolet radiation are:

• inflammatory diseases of the respiratory system;
• post-traumatic changes in the musculoskeletal system;
• inflammatory diseases of bones and joints (arthritis, arthrosis);
• vertebrogenic radiculopathy, neuralgia, myositis, plexitis;
• solar fasting;
• metabolic diseases;
• erysipelas.

Contraindications are:

• individual hypersensitivity to UV rays;
• hyperfunction of the thyroid gland;
• chronic renal failure;
• systemic connective tissue diseases;
• malaria.

Devices

Radiation sources of this type, like the previous one, are divided into integral and selective.

Integral sources are DRT-type lamps of various power, which are installed in OKN-11M (tabletop quartz), ORK-21M (mercury-quartz), UGN-1 (for group irradiation of the nasopharynx), OUN 250 (tabletop) irradiators. Another type of lamp - DRK-120 is designed for cavity irradiators OUP-1 and OUP-2.

A selective source is a fluorescent lamp LZ 153 for irradiators OUSh-1 (on a tripod), OUN-2 (tabletop). Erythema lamps LE-15 and LE-30, made of glass that transmits UV rays, are also used in wall-mounted, suspended and mobile irradiators.

Ultraviolet irradiation is dosed, as a rule, by a biological method, which is based on the ability of UV rays to cause reddening of the skin after its irradiation - erythema. The unit of measurement is 1 biodose (the minimum time of exposure of the patient's skin to ultraviolet radiation on any part of his body, causing the appearance of the least intense erythema during the day). Gorbachev's biodosimeter has the form of a metal plate, on which there are 6 rectangular holes closed by a damper. The device is fixed on the patient's body, UV radiation is directed at it, and 1 plate window is opened in turn every 10 seconds. It turns out that the skin under the first hole is exposed to radiation for 1 minute, and under the last - only 10 seconds. After 12-24 hours, threshold erythema occurs, which determines the biodose - the time of exposure to UV radiation on the skin under this hole.

There are the following types of doses:

• suberythemal (0.5 biodose);
• small erythema (1-2 biodoses);
• medium (3-4 biodoses);
• high (5-8 biodoses);
• hypererythemic (more than 8 biodoses).

Procedure procedure

There are 2 methods - local and general.

Local exposure is carried out on a skin area, the area of ​​which does not exceed 600 cm 2 . Apply, as a rule, erythemal doses of radiation.

The procedure is carried out 1 time in 2-3 days, each time increasing the dose by 1/4-1/2 from the previous one. One site can be exposed to no more than 3-4 times. A second course of treatment is recommended to the patient after 1 month.

With a general exposure, the patient is in the supine position; surfaces of his body are irradiated alternately. There are 3 treatment regimens - basic, accelerated and delayed, according to which, depending on the procedure number, the biodose is determined. The course of treatment is up to 25 exposures and can be repeated after 2-3 months.

Electrophthalmia

This term refers to the negative impact of medium-wavelength radiation on the organ of vision, which consists in damage to its structures. Such an effect can occur while observing the sun without the use of protective devices, while staying in a snowy area or in very bright, sunny weather at sea, as well as during quartzization of premises.

The essence of electrophthalmia is a burn of the cornea, which is manifested by severe lacrimation, redness and cutting pains in the eyes, photophobia and swelling of the cornea.

Fortunately, in the vast majority of cases, this condition is short-lived - as soon as the epithelium of the eye heals, its functions will be restored.

To alleviate your condition or the condition of those around you with electrophthalmia, you should:

• rinse eyes with clean, preferably running water;
• drip moisturizing drops into them (preparations such as artificial tears);
• put on protective goggles;
• if the patient complains of pain in the eyes, you can alleviate his suffering with compresses of grated raw potatoes or black tea bags;
• If the above measures do not give the desired effect, you should seek the help of a specialist.

shortwave radiation

It has the following effects on the human body:

• bactericidal and fungicidal (stimulates a number of reactions, as a result of which the structure of bacteria and fungi is destroyed);
• detoxification (under the influence of UV radiation, substances appear in the blood that neutralize toxins);
• metabolic (during the procedure, microcirculation improves, as a result of which organs and tissues receive more oxygen);
• correcting blood coagulation (with UV irradiation of blood, the ability of erythrocytes and platelets to form blood clots changes, coagulation processes normalize).

Indications and contraindications

The use of short-wave ultraviolet radiation is effective in the following diseases:

• skin diseases (psoriasis, neurodermatitis);
• erysipelas;
• rhinitis, tonsillitis;
• otitis;
• wounds;
• lupus;
• abscesses, boils, carbuncles;
• osteomyelitis;
• rheumatic heart valve disease;
• essential hypertension I-II;
• acute and chronic respiratory diseases;
• diseases of the digestive system ( peptic ulcer stomach and duodenum, gastritis with high acidity);
• diabetes;
• long-term non-healing ulcers;
• chronic pyelonephritis;
• acute adnexitis.

A contraindication to this type of treatment is individual hypersensitivity to UV rays. Blood irradiation is contraindicated in the following diseases:

• diseases of the mental sphere;
• chronic renal and hepatic insufficiency;
• porphyria;
• thrombocytopenia;
• callous ulcer of the stomach and duodenum;
• decreased blood clotting ability;
• strokes;
• myocardial infarction.

Devices

Integral radiation sources - DRK-120 lamp for OUP-1 and OUP-2 cavity irradiators, DRT-4 lamp for nasopharyngeal irradiator.

Selective sources are bactericidal lamps DB of various power - from 15 to 60 W. They are installed in irradiators of types OBN, OBSH, OBP.

In order to carry out autotransfusions with ultraviolet irradiated blood, the MD-73M Izolda apparatus is used. The source of radiation in it is the LB-8 lamp. It is possible to regulate the dose and the area of ​​irradiation.

Procedure procedure

The affected areas of the skin and mucous membranes are affected according to the schemes of general UV irradiation.

In diseases of the nasal mucosa, the patient is in a sitting position on a chair, slightly throwing his head back. The emitter is inserted into shallow depth alternately in both nostrils.

Irradiating the tonsils, use a special mirror. Reflected from it, the rays are directed to the left and right tonsils. The patient's tongue is protruded, he holds it with a gauze napkin.

The effects are dosed by determining the biodose. In acute conditions, they start with 1 biodose, gradually increasing it to 3. You can repeat the course of treatment after 1 month.

The blood is irradiated for 10-15 minutes during 7-9 procedures with a possible repetition of the course in 3-6 months.

ultraviolet radiation

The discovery of infrared radiation prompted the German physicist Johann Wilhelm Ritter to begin studying the opposite end of the spectrum, adjacent to its violet region. Very soon it was discovered that there is radiation with a very strong chemical activity. The new radiation is called ultraviolet rays.

What is ultraviolet radiation? And what is its influence on earthly processes and action on living organisms?

The difference between ultraviolet radiation and infrared

Ultraviolet radiation, like infrared, is an electromagnetic wave. It is these radiations that limit the spectrum of visible light from two sides. Both types of rays are not perceived by the organs of vision. The differences in their properties are due to the difference in wavelength.

The range of ultraviolet radiation, located between visible and X-ray radiation, is quite wide: from 10 to 380 micrometers (µm).

The main property of infrared radiation is its thermal effect, while the most important feature ultraviolet is its chemical activity. It is thanks to this feature that ultraviolet radiation has a huge impact on the human body.

The effect of ultraviolet radiation on humans

The biological effect exerted by different wavelengths of ultraviolet waves has significant differences. Therefore, biologists have divided the entire UV range into 3 areas:

• UV-A rays, this is near ultraviolet;
• UV-B - medium;
• UV-C - far.

The atmosphere enveloping our planet is a kind of shield that protects the Earth from powerful flow ultraviolet radiation coming from the sun.

Moreover, UV-C rays are absorbed by ozone, oxygen, water vapor and carbon dioxide by almost 90%. Therefore, the Earth's surface is mainly reached by radiation containing UV-A and a small fraction of UV-B.

The most aggressive is short-wave radiation. The biological effect of short-wave UV radiation upon contact with living tissues could have a rather destructive effect. But fortunately, the planet's ozone shield protects us from its effects. However, we should not forget that the sources of rays of this particular range are ultraviolet lamps and welders.

The biological effect of long-wave UV radiation is mainly erythemal (causing reddening of the skin) and tanning action. These rays are quite gentle on the skin and tissues. Although there is an individual dependence of the skin on exposure to UV.

Also, when exposed to intense ultraviolet radiation, the eyes can suffer.

Everyone knows about the effect of ultraviolet radiation on humans. But for the most part, it's superficial. Let's try to cover this topic in more detail.

How does ultraviolet light affect the skin (ultraviolet mutagenesis)

Chronic solar starvation leads to many negative consequences. Just like the other extreme - the desire to acquire "beautiful, chocolate color body" due to prolonged exposure to the scorching sun. How and why does ultraviolet radiation affect the skin? What threatens uncontrolled exposure to the sun?

Naturally, reddening of the skin does not always lead to a chocolate tan. Darkening of the skin occurs as a result of the body's production of a coloring pigment - melanin, as evidence of our body's struggle with the traumatic effect of the UV part. solar radiation. At the same time, if redness is a temporary condition of the skin, then the loss of its elasticity, the growth of epithelial cells in the form of freckles and age spots is a persistent cosmetic defect. Ultraviolet, penetrating deeply into skin, can cause ultraviolet mutagenesis, that is, damage to skin cells at the gene level. Its most formidable complication is melanoma - a tumor of the skin. Metastasis of melanoma can be fatal.

Skin protection from UV radiation

Is there UV protection for the skin? To protect your skin from the sun, especially on the beach, it is enough to follow a few rules.

To protect the skin from ultraviolet radiation, it is necessary to use specially selected clothing.

How ultraviolet radiation affects the eyes (electrophthalmia)

Another manifestation negative impact Ultraviolet radiation on the human body is electrophthalmia, that is, damage to the structures of the eye under the influence of intense ultraviolet radiation.

The striking factor in this process is the mid-wave range of ultraviolet waves.

This often happens under the following conditions:

• during the observation of solar processes without special devices;
• in bright, sunny weather at sea;
• while staying in a mountainous, snowy area;
• when quartzing rooms.

With electrophthalmia, there is a burn of the cornea. Symptoms of such a lesion are:

• increased lacrimation;
• cut;
• photophobia;
• redness;
• edema of the epithelium of the cornea and eyelids.

Fortunately, usually the deep layers of the cornea are not affected, and after the healing of the epithelium, vision is restored.

First aid for electrophthalmia

The symptoms described above can cause a person not only discomfort, but also real suffering. How to provide first aid for electrophthalmia?

The following steps will help:

• washing eyes with clean water;
• instillation of moisturizing drops;
• Sunglasses.

Compresses of wet black tea bags and raw, grated potatoes are excellent for relieving pain in the eyes.

If help does not work, see a doctor. He will prescribe therapy aimed at restoring the cornea.

All these troubles could be avoided by using sunglasses with a special marking - UV 400, which will completely protect the eyes from all types of ultraviolet waves.

The use of ultraviolet radiation in medicine

In medicine, there is a term "ultraviolet starvation". This state of the body occurs when there is no or insufficient exposure to sunlight on the human body.

To avoid the resulting pathologies, artificial sources of UV radiation are used. Their dosed use helps to cope with the winter deficiency of vitamin D in the body and increase immunity.

Along with this, ultraviolet therapy is widely used for the treatment of joints, dermatological and allergic diseases.

Ultraviolet radiation also helps:

• raise hemoglobin and lower sugar levels;
• improve the functioning of the thyroid gland;
• restore the functioning of the respiratory and endocrine systems;
• the disinfecting effect of UV rays is widely used for disinfection of rooms and surgical instruments;
• its bactericidal properties are very useful for the treatment of patients with severe, purulent wounds.

As with any major impact on human body must take into account not only the benefits, but also possible harm from ultraviolet radiation.

Contraindications for ultraviolet therapy are acute inflammatory and oncological diseases, bleeding, stages II and III of hypertension, active form of tuberculosis.

Each scientific discovery carries for humanity both potential dangers and huge prospects for its use. Knowledge of the consequences of exposure to ultraviolet radiation on the human body, allowed not only to minimize it Negative influence, but also to fully apply ultraviolet radiation in medicine and other areas of life.

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

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

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

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

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

Differences between infrared and ultraviolet

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

How does ultraviolet radiation affect humans?

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

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

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

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

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

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

UV mutagenesis or how UV affects human skin

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

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

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

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

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

How to protect yourself from ultraviolet radiation?

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

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

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

Electrophthalmia - the negative effect of UV radiation on the eyes

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

Electrophthalmia

These events most often occur when:

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

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

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

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

How to provide first aid for electrophthalmia?

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

First aid is pretty simple:

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

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

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

How is UV radiation used in medical practice?

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

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

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

With UV radiation, you can:

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

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

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 powerful impact 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 big influence 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 influence UV radiation on the human body. The result of these studies was the identification of the following useful properties: strengthening of human immunity, activation of protective mechanisms, improvement of blood circulation, vasodilation, increased vascular permeability, increased 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.

AT medical institutions have long been thought useful application artificial ultraviolet. 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. Thus, long-wave radiation is suitable for treatment respiratory tract, for damage to the osteoarticular apparatus, as well as in case of various damage skin. 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, in diseases of the ears, nose, with damage to the respiratory tract, with diabetes with 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 effect. 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 protected from forgery. 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 need to limit themselves in excessive visits to solariums and in a long stay in the open sun, in summer time use sunscreen, sprays or lotions, and wear sunglasses and close-fitting clothing made from natural fabrics.

There are also Negative consequences 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.