UV is that part of solar radiation that gives the skin a pleasant brown tint and promotes the body's production of vitamin D, which is essential for bones. This vitamin is also involved in the regulation of cell division and even to some extent prevents the development of colon and stomach cancer. Under the influence of sunlight, the so-called “pleasure hormones”, endorphins, are produced.
The human body knows how to protect itself from harmful compounds produced under the influence of sunlight. DNA damage is quickly repaired thanks to a special system that controls its integrity. And if a change does occur in the cell, it is recognized by the immune system as foreign and destroyed. Unfortunately, sometimes the body cannot cope with this damage, especially since UV suppresses the activity of the immune system. That is why, when arriving from warm countries, people often catch a cold.
At the same time, suppression of the immune system is the main mechanism for treating diseases such as atopic dermatitis and some other skin diseases using ultraviolet light.
UV is divided into three spectra depending on wavelength. Each spectrum has its own characteristics of impact on the human body.
- Spectrum C has a wavelength from 100 to 280 nm. This is the most active range; the rays easily penetrate the skin and cause a destructive effect on the cells of the body. Fortunately, such rays practically do not reach the surface of the Earth, but are absorbed by the ozone layer of the atmosphere.
- Spectrum B (UVB) has a wavelength of 280-320 nm and makes up about 20% of all UV radiation hitting the Earth's surface. These rays cause redness on the skin during sun exposure. They quickly cause the formation of active compounds in human skin, affecting DNA and causing disruption of its structure.
- Spectrum A, whose wavelength is 320-400 nm, accounts for almost 80% of the UV radiation that reaches human skin. Due to their longer wavelength, these rays have 1000 times less energy than UVB, so they cause almost no sunburn. They contribute significantly less to the production of biologically active substances that can affect DNA. However, these rays penetrate deeper than UVB, and the harmful substances they produce remain in the skin much longer.
Tanning is primarily damage to the skin.
The damaging effects of the sun gradually accumulate in the body, and can make themselves felt many years later in the form of skin cancer.
Parents, please note: if a child receives a sunburn that causes blisters, especially if this happens more than once, the risk of developing melanoma in the future increases several times!
People have different levels of protection from the harmful rays of the sun. People with dark skin have stronger protection, and people with red hair or blondes with blue eyes are more susceptible to the damaging effects of sunlight than others.
UV can sometimes contribute to the development of itchy rashes. With solar urticaria, itchy rashes resembling a nettle burn develop between 30 minutes and two hours after exposure. Polymorphic light rash - after 1-2 days. This disease also appears as itchy rashes at the site of radiation, but they go away more slowly than solar urticaria and look different. There are other diseases for which UV is a stimulus for development. For example, lupus erythematosus, rosacea, pellagra (vitamin B3 deficiency), and others.
Many medications taken orally can cause skin rashes when exposed to sunlight. There are some herbs that cause severe redness and blistering when exposed to the skin in the sun. First of all, these are plants from the umbrella family, among which the strongest is hogweed. In addition, celery, parsley, lime, parsnip and others can cause such dermatitis.
How to protect yourself from the harmful effects of the sun, and at the same time get the benefits and pleasure from it?
The answer is simple: you need to use sunscreen. It is not at all necessary to take a cream with maximum protection (SPF 50+). A product with SPF 15 already provides 80% protection from sun rays. This means that part of the UVB will reach the skin and have its positive effect. For sun protection creams to be effective, it is recommended to apply them 20 minutes before sunbathing and reapply them as recommended, usually every 2 hours. But be careful, using these drugs does not mean that you can stay under the sun indefinitely. It was this mistake that at one time led to a sharp increase in the incidence of melanoma - due to the absence of obvious sunburn thanks to the protective cream, some tanned for too long.
Scientists have discovered that in order for the body to produce the amount of vitamin D it needs, it is enough to “show the sun” to the face and hands for 10-15 minutes a day.
Specialists at the EMC Dermatovenereology and Allergology-Immunology Clinic will be happy to give detailed recommendations on sun protection for you and your entire family.
Solar hardening is a stronger type of hardening compared to other methods due to the action of sunlight. Hardening should be carried out carefully, because if the baby stays in the sun for too long, the baby may overheat the body and even suffer damage to the central nervous system. nervous system. Invisible ultraviolet rays contain the greatest activity and impact on the body.
There are direct and indirect sunlight. The first ones fall to the ground without obstacles, indirect or scattered ones penetrate through clouds, tree leaves, thin artificial canopies, etc. Scattered rays have a weaker effect on the body. Daylight consists of reflected (these are those that are not concentrated in one place) and diffused solar rays.
Due to its strong impact on the body, sunbathing for children has a number of limitations:
- It is advisable to begin hardening with sunbathing after mastering air baths.
- The smaller the baby, the greater the sensitivity to sunlight. Because of this, you need to be careful when sunbathing.
- It is recommended to take sunbathing 1.5 hours after a meal, and end half an hour before the next meal. This is necessary because in hot weather conditions for digestion worsen.
An important condition for the procedures is gradualism, which can be achieved in several ways.:
- The best time for procedures in the summer is the morning from 8 to 11 o'clock, or after 16 o'clock, in the fall and spring from 10 to 14
- it’s very good if these are scattered rays due to cloudiness
- during the first procedures, it is advisable to wear clothes that are appropriate for the weather, but cover as much skin as possible; gradually increase the area of sun exposure through clothing
- You can sunbathe in shaded areas
Direct sunlight children under 1 year old are contraindicated, but this does not mean that the baby cannot be taken out into the sun, because this is a very good prevention of rickets. For such children, only reflected and scattered rays are used.
You need to start hardening in sunny, not windy weather. Wear a bodysuit or a T-shirt with panties, and cover your head with a scarf. It is recommended to completely undress children after 30 minutes of being outside at a temperature in the shade of at least 22-23˚. The duration of the procedure for the baby should start from 2-3 minutes. increasing to 5-6 minutes a day, increasing every two days by a couple of minutes more. This is sufficient time for infants.
Children from 1-3 years old Sunbathing should be taken carefully, at a temperature in the shade of 20-22˚. Taking baths in direct sunlight should not exceed 15 minutes. in a day.
When choosing places for walking, keep in mind that an asphalt surface heats the air much more than a grass surface. Do not allow the child to overheat, and at the first signs (sweating, redness of the face), take the baby into the shade, give him something to drink, and wash him. To prevent the baby from overheating, maintain water balance, and be sure to offer your child something to drink when it’s hot in the summer.
Under the influence of sunlight, metabolism accelerates, the release of metabolic products through the skin improves, and the immune system is stimulated. Vitamin D, which is very important, especially for infants, is produced.
Beware of sunburn, heatstroke and solar overheating!
SUN RAYS
Orb of the action of the Sun aspect. Entering the sun's rays, leaving the sun's rays. For the Moon, the orb of convergence and exit is 17o, for the planets - 30o.
Astrological encyclopedia.
Nicholas Devore.
1947. See what “SUN RAYS” is in other dictionaries:
Hummingbird sun rays- ? Hummingbird sun rays ... Wikipedia direct sunlight
- - [A.S. Goldberg. English-Russian energy dictionary. 2006] Energy topics in general EN direct sunlight ... Technical Translator's Guide
Death rays- Death Ray is a hypothetical beam weapon capable of hitting a target at a distance using directed radiation. The first reports of death rays appeared among the ancient Greeks. Plutarch and Titus Livius mention that during the siege of Syracuse (212 ... Wikipedia RAYS OF THE SUN
- Make a discovery that is pleasant and useful in all respects. Imagine that the sun's rays are falling on you and warming your entire being... Big family dream book Sunbathing Physical Culture. Concise encyclopedic dictionary
SUNBATHING- a therapeutic and hygienic procedure in which nudity a person (or individual parts of the body) is exposed to more or less prolonged exposure to direct sunlight. Solar radiation contains visible and invisible (infrared and... Concise Encyclopedia of Housekeeping
SOLAR COSMIC RAYS- streams of accelerated charging. particles... Physical encyclopedia
Rays- They symbolize the Sun, divine brilliance, the favor of the deity, the emanation of nous. Corona racliata (crown of rays) hair of the Sun god, golden rays of Helios. The double halo of rays symbolizes the duality of the depicted deity. Rays emanating... Dictionary of symbols
Crepuscular rays- at sunset Crepuscular rays are the name of the rays of sunlight that pass through gaps in ... Wikipedia
Anti-twilight rays- Anti-twilight rays converging to the anti-solar point. The photo was taken from an airplane over the Pacific Ocean. Anti-twilight rays (English... Wikipedia
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The peculiarities of the impact of direct sunlight on the body today are of interest to many, primarily those who want to spend the summer profitably, stock up on solar energy and acquire a beautiful, healthy tan. What is solar radiation and what effect does it have on us?
Definition
Sun rays(photo below) is a flow of radiation, which is represented by electromagnetic oscillations of waves having different lengths. The spectrum of radiation emitted by the sun is diverse and wide, both in wavelength and frequency, and in its effect on the human body.
Types of sun rays
There are several regions of the spectrum:
- Gamma radiation.
- X-ray radiation (wavelength less than 170 nanometers).
- Ultraviolet radiation (wavelength - 170-350 nm).
- Sunlight (wavelength - 350-750 nm).
- Infrared spectrum, which has a thermal effect (wavelengths greater than 750 nm).
In terms of biological influence on a living organism, the most active are ultraviolet rays from the sun. They promote tanning, have a hormonal protective effect, stimulate the production of serotonin and other important components that increase vitality and vitality.
Ultraviolet radiation
There are 3 classes of rays in the ultraviolet spectrum that affect the body differently:
- A-rays (wavelength - 400-320 nanometers). They have the lowest level of radiation and remain constant in the solar spectrum throughout the day and year. There are almost no barriers for them. The harmful effects of sun rays of this class on the body are the lowest, however, their constant presence accelerates the process of natural aging of the skin, because, penetrating to the germ layer, they damage the structure and base of the epidermis, destroying elastin and collagen fibers.
- B-rays (wavelength - 320-280 nm). Only at certain times of the year and hours of the day do they reach the Earth. Depending on the geographic latitude and air temperature, they usually enter the atmosphere from 10 a.m. to 4 p.m. These sun rays take part in activating the synthesis of vitamin D3 in the body, which is their main positive property. However, with prolonged exposure to the skin, they can change the genome of cells in such a way that they begin to multiply uncontrollably and form cancer.
- C-rays (wavelength - 280-170 nm). This is the most dangerous part of the UV radiation spectrum, which unconditionally provokes the development of cancer. But in nature, everything is very wisely arranged, and the sun’s harmful C rays, like most (90 percent) of B rays, are absorbed by the ozone layer without reaching the Earth’s surface. This is how nature protects all living things from extinction.
Positive and negative influence
Depending on the duration, intensity, frequency of exposure to UV radiation in human body positive and negative effects develop. The first include the formation of vitamin D, the production of melanin and the formation of a beautiful, even tan, the synthesis of mediators that regulate biorhythms, and the production of an important regulator of the endocrine system - serotonin. That’s why after summer we feel a surge of strength, an increase in vitality, and a good mood.
The negative effects of ultraviolet exposure include skin burns, damage to collagen fibers, the appearance of cosmetic defects in the form of hyperpigmentation, and the provocation of cancer.
Vitamin D synthesis
When exposed to the epidermis, the energy of solar radiation is converted into heat or spent on photochemical reactions, as a result of which various biochemical processes are carried out in the body.
Vitamin D is supplied in two ways:
- endogenous - due to formation in the skin under the influence of UV rays B;
- exogenous - due to intake from food.
The endogenous route is quite difficult process reactions that occur without the participation of enzymes, but with the obligatory participation of UV irradiation with B-rays. With sufficient and regular insolation, the amount of vitamin D3 synthesized in the skin during photochemical reactions fully meets all the body's needs.
Tanning and vitamin D
The activity of photochemical processes in the skin directly depends on the spectrum and intensity of exposure to ultraviolet radiation and is inversely related to tanning (degree of pigmentation). It has been proven that the more pronounced the tan, the longer it takes for provitamin D3 to accumulate in the skin (instead of fifteen minutes to three hours).
From a physiological point of view, this is understandable, since tanning is a protective mechanism of our skin, and the layer of melanin formed in it acts as a certain barrier to both UV B rays, which serve as a mediator of photochemical processes, and class A rays, which provide the thermal stage of transformation in the skin provitamin D3 into vitamin D3.
But vitamin D supplied with food only compensates for the deficiency in case of insufficient production during the process of photochemical synthesis.
Vitamin D formation during sun exposure
Today it has already been established by science that to ensure daily requirement In endogenous vitamin D3, it is enough to stay in open sunlight class UV rays for ten to twenty minutes. Another thing is that such rays are not always present in the solar spectrum. Their presence depends both on the season of the year and on geographic latitude, since the Earth, when rotating, changes the thickness and angle of the atmospheric layer through which the sun's rays pass.
Therefore, solar radiation is not always able to form vitamin D3 in the skin, but only when UV B rays are present in the spectrum.
Solar radiation in Russia
In our country, taking into account the geographical location, class B rich UV rays are distributed unevenly during periods of solar radiation. For example, in Sochi, Makhachkala, Vladikavkaz they last about seven months (from March to October), and in Arkhangelsk, St. Petersburg, Syktyvkar they last about three (from May to July) or even less. Add to this the number of cloudy days a year and the smoky atmosphere in large cities, and it becomes clear that the majority of Russian residents lack hormonotropic solar exposure.
This is probably why intuitively we strive for the sun and rush to the southern beaches, while forgetting that the sun’s rays in the south are completely different, unusual for our body, and, in addition to burns, can provoke strong hormonal and immune surges that can increase the risk of cancer and other ailments .
At the same time, the southern sun can heal, you just have to follow a reasonable approach in everything.
