Uva and uvb ultraviolet rays. Uvb and uva beams: how are they different and how do they affect the skin? Such multifaceted ultraviolet

Summer is coming! ☀ The sun is shining with might and main, someone is already planning a vacation, which means it's time to talk about sunscreens.

After a long winter and frost, I especially want to soak up the sun. But the sun also has “ dark side"Which can cause significant harm to our skin and the entire body. To enjoy the sun safely, you need to study it from all sides.

In this post, we will talk in detail about the types of sun exposure, sunscreens, what is SPF, PPD, PA, IPD on sunscreen cans and what SPF products are.

Solar radiation

Sunlight is divided into 3 spectra:

  • ultraviolet;
  • visible light;
  • infrared radiation (heat).

From the point of view of exposure to the skin, we are interested in ultraviolet rays (ultraviolet), which, in turn, are divided into UVC, UVB and UVA.

UVC rays (ultraviolet C rays)

These are the strongest and most dangerous rays. But, luckily for us, they are absorbed by the ozone layer and do not reach the Earth's surface. Therefore, UVC rays do not affect the skin in any way, and we will not talk about them further.

UVB rays (ultraviolet B rays)

They are also partially absorbed by the ozone layer, but the remains reach the surface of the Earth. These rays are most active in the period from spring to autumn, from 10 am to 4 pm.

They act on the surface of the skin, penetrate into its upper layer (epidermis), but do not reach the deep layers (dermis). It is these rays in small doses that cause sunburn, and in large doses - sunburn, are involved in photoaging, can cause skin cancer and eye damage.

UVA rays (ultraviolet A rays)

They are divided into long (UVA1) and short (UVA2).

They are not absorbed by the ozone layer at all and reach the surface of the Earth. Equally active throughout the year, at any time of the day. Can penetrate glass and light clothing. The amount of UVA rays is many times higher than the amount of UVB rays.

These are the most insidious rays. They penetrate the epidermis and deep into the dermis, damaging the DNA of the cells. They change their structure, increase the level of genetic mutations and can cause skin cancer.

UVA rays are responsible for hyperpigmentation, uneven skin tone, dryness and freckles. Much less likely than UVB, but they can also cause sunburn and sunburn. They are actively involved in photoaging. Prolonged exposure to high UVA rays damages collagen and elastin fibers. This leads to wrinkles and premature aging.

UVA are the main rays used in tanning salons.

Important nuances

  • All rays become stronger at altitude (eg in the mountains). Each kilometer upwards increases the radiation intensity by as much as 12%. Therefore, in the mountains, sunscreen (or better even a stick) is an absolute must-have.
  • All rays can be reflected to varying degrees from surfaces - snow, ice, water, and even asphalt, grass and sand. It also increases the intensity of the radiation at times. Therefore, protection is always important - while swimming at the sea, in a ski resort and in the city.
  • Up to 80% of the rays penetrate the clouds. Therefore, protection from the "sun" is important even on cloudy days.

Sun protection

When it comes to the sun, the main thing is to know when to stop. A small amount of UV light is good for the skin and body and is necessary for the production of vitamin D.

Excessive UV radiation damages the skin and its immune system, thickens it, disrupts blood circulation, and causes photoaging. Skin aging is 70% dependent on UV radiation.

Moreover, any dose of UV radiation remains in the body and accumulates throughout life. Severe burns are especially dangerous - up to blisters and peeling skin. The body remembers every time you "fry".

Sunburn continues to develop (get worse) for 12-24 hours after it occurs.

In order to protect our delicate skin from the negative effects of ultraviolet radiation and use sunscreens in cosmetics.

Sun filters

There are various substances that selectively absorb, reflect and neutralize the effects of UV rays. They are called sunscreen or UV (UV) filters.

UV filters are also added to cosmetics to protect them from destruction and decomposition in the light.

Filters are physical, chemical, and natural.

Physical filters

Reflect Sun rays. They are distributed over the surface of the skin, forming a dense, impenetrable film. Acts as a mini-carapace, shield or screen, from which the sun's rays "ricochet" like darts.

Funds based on physical filters alone typically provide a baseline and medium protection factor.

Examples of physical filters (what to look for on the label): zinc oxide; titanium dioxide.

  • "Pros +". These are "broad spectrum" filters - they protect against both UVB and UVA rays. They are not absorbed by the skin and do not react with it. They are effective even at low concentrations, are non-toxic, photostable (do not decompose in light) and have a low cost. Begins to act immediately after application to the skin.
  • "Minuses - ". At high concentrations, they create the effect of white on the skin, dense, opaque, can dry, non-waterproof, do not combine well with many components of cosmetic formulas. Can theoretically clog pores (with tendency).

The best choice for sensitive, hypersensitive, reactive skin, for organic lovers and for children. Children's sunscreen cosmetics should only contain physical filters.

Chemical filters

Absorb UV radiation and block its penetration into the skin. Some chemical filters also reflect and scatter rays. Distributed over the surface of the skin and in the upper layer of the epidermis. They practically do not penetrate deeper. They do not enter the body, do not have any harmful effects on cells and the circulatory system, and do not cause hormonal imbalances.

Depending on the specific substance, they protect against either UVA or UVB, or both.

Examples of chemical filters (what to look for on the label): avobenzone; mexoryl (Mexoryl SX and XL); tinosorb (Tinosorb S and M); octocrylene; padimate O; cinnamates (-cinnamate); oxybenzone, benzophenone-3 (oxybenzone, benzophenone-3); sulisobenzone; octyl salicylate.

  • "Pros +". They are very effective. Water resistant. Provides a high protection factor. They do not leave marks on the skin, usually liquid, colorless and odorless.
  • "Minuses - ". How chemical filters work is essentially a chemical reaction on the skin. They come into contact with radiation, absorb it and generate heat. As a result, the temperature of the skin rises. They can cause allergies and provoke the development of rosacea. They can be photostable or not. They begin to act only 20-30 minutes after application to the skin.

The lettering "sunblock" on the bottle usually implies the presence of physical filters, the words "sunscreen" - chemical filters. However, these are very conventional concepts. The Americans, for example, have banned the use of sunblock because no product can completely block the sun's rays.

Natural filters

Many base oils are natural or natural filters. They can both reflect and absorb UV radiation.

Of course, you shouldn't rely entirely on natural filters for sun protection.
They are not enough. First, they create a film that is too thin and insufficiently effective. Secondly, oils attract sun rays and increase tanning. And thirdly, the SPF values ​​are too different. But in combination with physical and chemical natural filters are wonderful.

Filter wear and photostability

Physical and chemical filters tend to "wear out".

The physical ones wear off, for example, on contact with a towel. And each molecule of the chemical filter, when a photon of the sun's ray hits it, dies and is converted into heat. Thus, it is consumed as, for example, gasoline for a car or food for the body.

That is why it is necessary to constantly update the protection. The more sun, the more often the repetition.

Some substances are more resistant to light (photostable), others die less and faster. Some filters can stabilize others (for example, mexoryl stabilizes avobenzene), while others, on the contrary, destroy each other (like octinoxate and avobenzene).

In addition, not all filters independently provide protection against both types of rays. Therefore, a whole cocktail of filters is used in sunscreens (as a rule, there are about 5 of them). The higher the protection, the more filters you can find in one jar.

A competent sunscreen must provide protection from both UVB and UVA rays. The ideal ratio of UVB to UVA filters is 1: 1.

What to look for on the label

SPF (UVB protection)

SPF stands for Sun Protection Factor, i.e. sun protection factor. This an indicator that determines the ability of a cosmetic product to protect the skin from burns... It is calculated by smart uncles in white coats in laboratories.

The SPF calculation measures how much UV radiation it takes for our unprotected skin to start sunburn compared to skin covered with sunscreen. The SPF value indicates what% of UV rays will be blocked. It is defined in numbers from 2 to 100. The higher the SPF, the more rays will be reflected (absorbed), and the higher the level of protection of the product from sunburn.

Probably, many people know the formula: the amount of time you can spend in the sun without sunburn without sunscreen (for example, 30 minutes) x SPF value (for example, 10) = the amount of time you can peacefully fry in the sun, smeared with this SPF (in our case - 30x10 = 300 minutes, that is, a whole 5 hours). It would seem that everything is correct? But no.

Why? Because SPF does not duration sun exposure and number solar irradiation. Duration is just one factor. The intensity of the radiation is equally important. For example, 1 hour in the sun at 9 am in terms of the effect on the skin is equal to 15 minutes at 1 pm. Another important factor is geography. The closer to the equator, the more intense the solar radiation. Do not forget about the weather, you can get a burn under a cloudy sky. Therefore, it is impossible to be guided only by the above formula.

Important! SPF only determines the degree of protection against sunburn (exposure to UVB rays), but it does not in any way determine the degree of protection against the harmful effects of UVA rays.

SPF values

For clarity, SPF can be divided according to protection levels.

  • SPF (2-10) - basic.
  • SPF (15-25) - medium.
  • SPF (30-100) - high.

But no cream, even with SPF 100, provides 100% protection against radiation. For total protection from the sun can only be given by a deaf bunker deep underground. Therefore, one should not think that having smeared with "weaving" it is possible to "fry on the beach" all day without loss of health.

Another misconception is that, for example, SPF 30 provides 2 times more protection than SPF 15, and SPF 60 - 2 times more protection than SPF 30. This is not the case. The difference between SPF 15 and 100 is only 6%.

Let's see what% of the sun's rays a particular SPF reflects.

SPF 2 - 50%; SPF 6 - 83%; SPF 10 - 90%; SPF 15 - 93%; SPF 20 - 95%; SPF 25 - 96%; SPF 30 - 97%; SPF 45 - 97%; SPF 50 - 98%; SPF 60 - 98%; SPF 100 - 99%.

As you can see, it doesn't make much sense to smear too much SPF. SPF 100 is more of a marketing ploy.

Moreover, the higher the SPF, the fatter and denser it feels on the skin. SPF 15 is much nicer to the touch than SPF 30. And SPF 100, mmm ... let's just say it's fucking. ☹

When choosing an SPF, consider the following factors:

  • phototype, skin color- red-haired owners of porcelain skin with freckles need a higher SPF (from 50);
  • season- a higher SPF is needed in summer than in winter;
  • Times of Day- from 10 am to 4 pm UVB rays are most active;
  • cloudy- cloudless skies require a higher SPF;
  • geography, climate and sun intensity- where you are - near the Equator or beyond the Arctic Circle - matters, the hot UAE and the middle zone of Russia require different degrees of protection;
  • location- the sea and mountains require a higher SPF than a dacha in the Moscow region.

PPD, PA and IPD (UVA protection)

A common measure of UVB protection is the SPF index. The PPD, PA and IPD indices are the measure of protection against UVA rays. Generally accepted, accurate and ideal UVA protection measures for this moment do not exist in nature. V different countries different indices are used.

Persistent Pigment Darkening (PPD)

Literally - persistent darkening of the pigment. Originally developed in Japan, adopted in Europe and the USA. Most European and American funds you will find this particular icon.

Shows how the product will reduce the penetration of UVA rays into the skin. The higher the number, the better, the minimum recommended index is 8, the maximum is 42. This means that 42% of the rays will be blocked.

It is the PPD index that is currently considered the most accurate in Europe and America.

Protection Grade of UVA (PA)

Literally - the degree of protection against UVA. It appeared relatively recently and was adopted in Japan and Korea. Same as PPD. It is indicated by + from 1 to 4.

The ratio of PA and PPD indices: PA + = PPD 2-4, PA ++ = PPD 4-8, PA +++ = PPD 8-16, PA ++++ = PPD 16 and higher.

The more + the PA has and the higher the number and PPD - the better the protection.

Immediate Pigment Darkening (IPD)

Literally - instant darkening of the pigment.

The maximum index is 90. It means that the skin is 90% protected from UVA rays.

If neither PPD, PA, nor IPD is on the jar, look for UVA in a circle without numbers. It means UVA protection, but not specifically. Also circled UVA means that the ratio of UVA to UVB filters is 1: 3.

What else is added to sunscreen

Excessive sun exposure can lead to the formation of free radicals in the body - unstable and highly reactive oxygen molecules that damage tissues at the molecular level, destroying and altering DNA.

Forms of sunscreens

  • Emulsions (creams and gels)- the most convenient, pleasant to use and effective.
  • Oils- less convenient and effective due to a thin layer, attract the sun's rays.
  • Sticks- wax-based, as a rule, the most water-resistant and contain physical filters, ideal for local application, for example, on the nose, on the whole body, uncomfortable.
  • Powders- make-up with SPF, additional protection option.
  • Sprays, aerosols- for the body: a thin layer, they do not guarantee evenness, usually you cannot just pollinate and go - you still need to rub, aerosols are dangerous if inhaled; for hair and head - sprays are ideal.

2 life hacks to note

  • If you forgot to spread the SPF cream before sticking your nose in the sun, use an oil-based product. They create a protective film faster.
  • If you need "instant protection" before bathing, use a stick. They are the most water resistant and contain physical filters that take effect immediately.

Daily and active remedies

According to the American Skin Cancer Foundation, all cosmetic products can be divided into "daily" and "active".

  • Daily.

Provides protection against occasional short-term UV radiation.

They must: contain an SPF of 15 or higher, provide full protection against the full spectrum of UVA rays, and not cause contact irritation and phototoxic reactions.

These are day creams, eye creams, lip balms, foundations and other decorative cosmetics.

  • Active.

Provides protection against prolonged UV radiation.

They must: contain an SPF of 30 or higher, provide full protection against the full spectrum of UVA rays, be water resistant (retain protection for 40 or 80 minutes of bathing), and not cause contact irritation and phototoxic reactions.

These are beach sunscreens, sports sunscreens, protective sticks with zinc and titanium, and children's cosmetics.

Morality. The optimal SPF value for the city for every day is 15. If you are going to the sea, to the mountains or plan to be on outdoors, choose SPF 30 (or higher). But then again - if your city is in the Emirates or Africa - start at 30.

Summarize

The sun's radiation directly affecting the skin is divided into 2 types: UVA and UVB. UVB rays cause sunburn and burns, UVA rays - pigmentation, photoaging, increase the risk of skin neoplasms. A moderate amount of sun is good, an excess is bad.

To keep the skin out of trouble, cosmetics manufacturers use sunscreens. They are divided into physical and chemical. An optimal cream contains both and provides protection from UVA and UVB rays at the same time.

SPF stands for UVB Protection Index. PPD, PA, IPD - indexes of protection against UVA rays. The higher their values, the stronger the protection.

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Stay tuned, upgrade your cosmetic literacy and be beautiful.

Until next time on air LaraBarBlog. ♫

Main part solar energy reaches the earth in the form of three components: visible light (40%) and infrared radiation (50%), ultraviolet radiation (10%). The most significant and well-studied part of solar radiation is ultraviolet rays. They are represented by three types of different wavelengths and are designated by letters of the Latin alphabet: UVC rays - the shortest (190-280 nm). UVB rays - medium wave (280-320 nm) and UVA rays - long wave (320-400 nm). Speaking about the effects of ultraviolet radiation on humans, they mean exposure to UVB and UVA rays. Short UVC rays are almost completely absorbed by the ozone layer of the atmosphere, as are short and very active cosmic gamma rays. These rays are detrimental to all life on the earth's surface, so the problem of the integrity of the ozone layer is of concern to scientists around the world. Artificial UVC rays are used to decontaminate premises.

UVB rays are scattered more when passing through the atmospheric layers than UVA, with increasing latitude the level of UVB radiation decreases. In addition, its intensity depends on the season and varies significantly during the day.

Most of the UVB is absorbed by the ozone layer, unlike UVA, and its share of the total UV energy in the summer afternoon is about 3%.

The penetrating ability through the skin barrier is also different. So, UVB-rays are reflected by 70% by the stratum corneum, weakened by 20% when passing through the epidermis, the dermis reaches only 10%. Due to absorption, reflection and scattering, UVA rays penetrate into the dermis with less losses - 20-30% and about 1% of the total energy reaches the subcutaneous tissue.

For a long time, it was believed that the share of UVB rays in the damaging effect of ultraviolet radiation is 80%, since it is this spectrum that is responsible for the occurrence of sunburn erythema. To date, a number of biological effects of solar radiation are known with the predominant value of different ranges of ultraviolet radiation. Darkening of melanin (light and quickly passing sunburn) occurs under the influence of UVA within a few hours and is associated with the photooxidation of already existing melanin and its rapid redistribution along the processes of melanocytes into epidermal cells. A delayed tan develops after 3 days and is caused by UVB rays. It is due to the active synthesis of melanin in melanosomes, an increase in the number of melanocytes and the activation of synthetic processes in previously inactive melanocytes. Slow tanning is more stable.

Vitamin D 3 is synthesized under the influence of UVB rays. A daily exposure of the face and hands for about 15 minutes is considered sufficient, according to the WHO. It is also necessary to take into account the geographical factor, since at some latitudes there is a high level of UVA radiation and low UVB rays, which may be insufficient for the synthesis of vitamin D 3.

Strong exposure to ultraviolet radiation is manifested in the form of solar erythema and / or burns. UVB rays are erythematogenous. The term "minimum erythemal dose" (MED) is often used to assess the effect of UV radiation - the energy exposure to UV radiation, which causes barely noticeable erythema of previously unirradiated skin. For fair skin 1 DER is equal to 200-300 J / m 2. However, the amount of radiation required for the development of erythema is purely individual and depends on the type of skin, its physiological sensitivity to sunlight.

The effect of UVB on normal skin, not used to the sun, causes a photoprotective reaction - the synthesis of melanin by melanocytes, an increase in the number of melanosomes. This limits the supply of ultraviolet radiation to the basal layer and to melanocytes. Along with this, hyperplasia of the epidermis is observed due to the proliferation of keratinocytes, which also leads to scattering and weakening of UV radiation. These changes are adaptive in nature and allow the skin to withstand subsequent irradiation.

UVA radiation does not cause sunburn. However, with prolonged exposure (months, years), it is these rays that cause the appearance of signs of photoaging, as well as UV-induced carcinogenesis. UVA is the main factor in the cytotoxic effects of sunlight in the basal layer of the epidermis, due to the formation of free radicals and damage to DNA strands. Since UVA radiation does not contribute to the thickening of the epidermis, the tanning it produces is ineffective as a protection against subsequent radiation.

The effect of ultraviolet radiation on immunity is known. A number of researchers suggest that UV radiation suppresses the responses of the human immune system. UVA and UVB radiation can activate the herpes virus. Experimental data on the possible activation of HIV, according to the WHO, have not been confirmed. However, with a lack of ultraviolet radiation, a decrease in immunity is also noted (the titer of complement decreases, the activity of lysozyme, etc.). The use of prophylactic courses of UV radiation in conditions of its deficiency (in northern latitudes) has a pronounced adaptive effect.

Langerhans cells (migrating dendritic cells) play a role in immunological recognition and are extremely sensitive to ultraviolet light. Their function is impaired when suberythemal doses of irradiation (1/2 DER) are reached. Noteworthy is the longer period of recovery of the population of these cells after UVA irradiation (2-3 weeks) than after UVB (48 hours).

It is believed that the influence of UV radiation on the incidence of skin cancer has been reliably established. Experts differ on the influence of UV on the occurrence of melanoma. Often there is a predominant development of melanomas in open areas of the body that have been exposed to excessive exposure to sunlight. The incidence of melanoma continues to rise, with fewer blacks in the same geographical areas. In Europe, morbidity and mortality are much higher than in the Nordic countries.

Paradoxically, melanoma mortality decreases with increasing UVB dose. Such a positive effect can be associated with both the stimulation of the photoprotective effect and the synthesis of vitamin D. Oncologists consider the hormonal form vit D 3 -calcitriol, synthesized in the kidneys, as a factor regulating the differentiation and proliferation of tumor cells. The required dose for the synthesis of vitD3 is small and amounts to about 55 MED per year.

Among the factors of natural human photoprotection, a special place belongs to melanin. The quantity and quality of melanin determines resistance to ultraviolet exposure and is associated with the color of the skin, hair, eyes. The activity of melanogenesis and the ability of the skin to sunburn formed the basis for dividing people into phototypes.

Type 1 - always burn, never sunbathe (redheads, albinos);

Type 2 - sometimes they get burned, they hardly get a tan (blondes);

Type 3 - sometimes burn, may sunburn (Caucasians);

Type 4 - only small areas are burned, they always sunbathe (Asians, Indians);

Type 5 - rarely burn, acquire an intense tan (Dravidians, Australian aborigines);

Type 6 - they never get burned, they sunbathe strongly (negroids).

There are significant differences in the number and distribution of melanosomes in white and black people: the latter have a greater number of melanosomes, and with a more even distribution in the skin. As a result, even a tanned white-skinned person is less protected from the effects of ultraviolet radiation.

Among the factors of natural photoprotection, the DNA repair system is especially important. Cells have a number of defense mechanisms through which they can repair damage to DNA strands. In particular, the mechanism of repair by cleavage is used, during which a small section of the damaged DNA strand is removed and replaced by a newly synthesized intact section. Many cells turn on a photoreactivation mechanism for DNA repair, with the help of which damage can be repaired without splitting the DNA molecule. In this case, an enzyme binds to a DNA molecule containing a pyrimidine dimer. As a result of absorption of light (300-500 nm) by the "DNA enzyme" complex, the enzyme is activated and restores the damaged part of the molecule, cleaving the dimers to form normal pyrimidine bases.

As you know, there are two main types of ultraviolet radiation - UVA and UVB. Tanning salons, regardless of type, use a combination of these rays to help you tan more efficiently.

It is worth noting that tanning penetrates the epidermis - the top layer of the skin. Under the influence of UVB rays, melanin, which makes the skin turn red, is formed by melanocytes within the epidermis.

Under the influence of UVA rays, melanin begins to oxidize, which contributes to the darkening of the shell to a beautiful golden color.

Low pressure tanning salons are equipped with special fluorescent tubes capable of emitting high amounts of UVB rays. As for the high pressure lamps, they are much smaller and can be used for tanning the face as well as for giving a beautiful bronze tint to the skin of the whole body.

Some tanning salons allow you to use just as much UVB rays as needed to stimulate melanin, and simply filter out the rest. Thus, only the UVA rays needed to darken the skin are passed through.

It should be noted that tanning is the body's natural defense mechanism against the sun's rays. The outer layer of the skin is renewed every 28 days under optimal conditions. If it is exposed to a lot of UVB rays, the skin will need to peel off and cleanse every 5-10 days in order to protect the body. That is why tanning salons, which operate at low pressure, have to be visited more often in order for the skin color to remain beautiful.

At low pressure, due to the filtering of excess UVB rays, the exfoliation of the skin remains normal and natural, which means that the tan is fixed for a longer period.

Let's move on to the answers to the most common questions about high pressure light.

- What is light and what is meant by ultraviolet radiation?

Even from school wisdom, many remember that the visible part of the spectrum is called light. But in our context, it is important to note that visible light is only a small part of the energy range required for tanning.

Light is measured, as you know, by its wavelength, and this is a very small interval, the unit of which is nanometers (nm).
There are different types of light associated with the tanning process. The ultraviolet light we hear is made up of UVA and UVB rays, just like infrared and visible light.

The strongest form of UV light that is responsible for sunburn is UVB rays. They are able to start the tanning process, but they are not enough to make it beautiful in our usual sense. UVA rays are responsible for the attractive dark golden color of the skin. Of the visible light available to the naked eye, violet is the most commonly used color.

- Tell us more about infrared radiation.

Outside the visible part, this is light with a wavelength of more than 700 nm. It is associated primarily with heat, although in terms of wavelength we correlate with the warmth of the sun during dawn or late dusk. However, infrared light associated with heat is often the cause of tanning discomfort.

- What are UVA and UVB, how are they different?

UVA is the portion of ultraviolet radiation that has a wavelength between 320 nm and 400 nm. As mentioned above, the area of ​​responsibility of these waves during tanning is oxidation.

UVB refers to the portion of ultraviolet radiation with wavelengths between 280 nm and 320 nm. Such rays are responsible for initiating the tanning process.

- What combination of rays does natural sunlight contain?

The composition of natural sunlight is not constant. It varies significantly in composition depending on the season, time of day, and proximity to the equator. In the early morning, UVB levels are fairly low, as UVB waves are reflected by the Earth's geomagnetic envelope. Then it begins to gradually increase and reaches its peak by noon. In the middle of a summer day, its concentration often reaches 10% of the entire spectrum of sunlight.

- What kind of light is natural for a tanning studio?

In order to ensure the achievement of the greatest effect during tanning, a combination of different types of rays is used in tanning salons. In fact, it is through her that professionals have the opportunity to manage both the effective tanning process and its functional characteristics.

- What are the features of low pressure tanning salons?

There are no fluorescent lamps in these tanning salons. Low pressure tanning salons are characterized by high power in the UVB range and low power in the UVA range.

- What is the difference between medium pressure solariums?

These tanning salons are equipped with high-pressure face lamps, while the entire tanning bed is operated at low pressure.

- What are the characteristics of high pressure tanning beds?

This type of tanning bed uses exclusively quartz lamps, which are characterized by a lower UVB content, which means that they significantly reduce the risk of burns and ensure a normal renewal process for the skin. That is why tanning under high pressure lamps is ensured for a longer period.

So, conclusions about high and low pressure lamps.

Tanning salons that operate at low pressure have a high concentration of UVB rays, while high pressure tanning salons operate at high UVA levels and lower UVB rays. As outlined above, UVA allows the tan to be more permanent. The risk of burns from UVB rays in high pressure tanning salons is minimized.

We will be glad to see you in the professional Mercy tanning studio.

Why UVA is More Important than UVB and Zinc Oxide is Better than Titanium Dioxide.

About the protection of the skin from ultraviolet radiation already. Most people know that there are chemical and physical filters, the sunscreen needs to be renewed every two hours, and the best sunscreens are. However, there are many subtleties that are directly related to how ultraviolet light affects your aging and appearance. Here are five important facts you didn't know about.

UVA protection is more important than UVB

Ultraviolet exposure has only three types of radiation: UVA, UVB and UVC. The last rays are the shortest and do not pass through the Earth's atmosphere. UVB middle length and is responsible for sunburn and skin burns (B stands for Burn), and UVA rays are the longest and most dangerous for us (A = Aging). They cause skin aging, cancer and other diseases of the epidermis.

When we are outdoors, our skin's UVA rays are 20 times stronger than UVB. At the same time, not many people know that the popular SPF protection factor, which everyone is guided by, protects only from UVB rays and allows us not to sunburn or get burnt. Much more important when choosing sunscreen focus on the degree of UVA protection. It is indicated on the packaging of the product by the factor PA with pluses (for example, PA ++ or PA +++++). Sometimes you can also find the Full Protection formulation, which also means that it protects against UVA rays. Dermatologists advise choosing sunscreens with PA ++++ and PA +++++ - the plus signs in this case indicate the degree of penetration of UVA rays into the skin (and protection against this penetration).

Zinc oxide is better than titanium dioxide

Zinc Oxide and Titanium Dioxide are the best known and most effective minerals that provide UV protection. They can be found in a professional product, and in sanskrin for children, and in the cheapest sunscreen. Unlike chemical filters, which block UVA and UVB rays in the skin, these minerals reflect radiation from the surface.

In most products with a physical protection factor, you can find both zinc oxide and titanium dioxide in different proportions. The undoubted advantage of the latter is in a more transparent texture that does not leave a white coating on the face. However, research suggests that it is zinc oxide that provides far greater protection, especially against UVA rays. Its unconditional minus is white. However, the latest generation of sanxrin contains micronized zinc oxide, which does not have this disadvantage. Of course, titanium dioxide should not be ignored altogether, but make sure that zinc oxide is higher than titanium oxide on the list of ingredients on the package.


Use chemical and physical filters together for complete protection

Most modern Sanskrins contain both chemical and physical filters. However, their biggest drawback is that they need to be washed off and reapplied every two hours. The point is that chemical filters (like oxybenzone, avobenzone, Mexoryl SX and Mexoryl SL) absorb UV rays in the skin and convert them into a safe form of energy. However, this effect only lasts for two hours in direct sunlight. Then chemical filters are turned into, which harm the skin at least as much as UVA.

To maximize the protection of the skin from ultraviolet radiation, dermatologists advise first to apply a sunscreen only with chemical filters, wait 30 minutes (this time is required to activate the product in the skin), and then apply a sunscreen on top only with zinc oxide and titanium dioxide. Thus, at first, the physical filters will protect the skin from the sun, and when they wear off (the minerals are in powder form), then the chemical filters will take over.


Pomegranate extract will help not to sunburn

Skin beauty supplements are appealing to consumers, however, studies have shown that pomegranate extract nutritional supplements do have a beneficial effect on the skin. This effect is achieved thanks to the content of ellagic acid, which whitens the skin, adds radiance and normalizes the work of melanin. Sure, this is a step for beauty freaks and white skin aficionados, but it still works.

A study was published in the American Journal of Nutritional Science and Vitaminology on the effects of ellagic acid on sun protection. Thus, when taking a supplement of 200 mg per day in the control group, the skin was noticeably less damaged after exposure to ultraviolet radiation compared to those who took placebo.


UVA rays penetrate through windows

Everyone knows that you cannot sunbathe through glass. The thing is that UVB rays are responsible for the bronze tint of the skin, which do not penetrate through the windows. However, 62% of dangerous UVA rays can damage your skin, even when you are indoors. There are two ways out: do not forget about sun protection if you are sitting by the window, or get special glasses with full UV protection.

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UVR

Ultra Violet Radiation - Ultraviolet radiation.

SPF

Sun Protection Factor - sun protection factor.

A simple formula explains the SPF function:

The SPF level (for example, SPF 30) we multiply the number of minutes during which you burn out in the sun without protection, and we get the number of minutes during which you are provided with protection from the sun without the threat of burns. That is, if you usually burn out after 10 minutes of exposure to the sun without protection, then with an SPF of 30, the period of relatively safe exposure to the sun increases to 300 minutes.

Many believe that SPF values ​​(5, 15, 30, 40, 50) differ in the strength of protection and nothing more. This is not entirely true. It is important to know that SPF 15 protects from about 95% of the B rays (UVB), and SPF 30 from about 98% of the B rays. Almost the same amount. That is, by increasing the protection factor (SPF), you do not increase the degree of protection, but protection time.

UVC

Ultraviolet rays of group C.

UVC radiation has the shortest wavelengths - 100-280 nm, which do not reach the Earth's surface due to the ozone layer.

UVB

Group B ultraviolet rays.

UVB radiation has a wavelength of 280-320 nm. A small amount of it penetrates the ozone layer, accounting for less than 10% of all ultraviolet radiation reaching the Earth's surface. This type of radiation causes skin aging, sunburn, suppression of the immune system, damage to DNA structure and skin cancer.

The most affordable sunscreens absorb or reflect UVB radiation and protect against sunburn, which damages DNA molecules. They do not contain UVA protection formulas. Therefore, even if protected by anti-UVB agents, the risk of skin damage, weakening of the immune system and photoaging remains.

But at Clinique, all the products in the Clinique Sun sunscreen line filters are included that protect both from the rays of the group B, and from rays of group A - more harmful and less noticeable in their effect. The ratio of these filters is 3: 1. According to European legislation, this ratio is recognized as optimal for the full protection of the skin today.

UVA

Ultraviolet rays of group A.

UVA radiation has a wavelength of 320-400 nm and accounts for about 90% of the ultraviolet radiation that reaches the Earth's surface. It is believed that this type is not as dangerous as UVB radiation, however, it has also been noted as a cause of sunburn, and most importantly, as a major factor in suppressing the immune system.

UVA / UVB radiation affects the skin in different ways. While UVB-induced suppression of the immune system, damage to DNA structure and photoaging are mainly the result of sunburn, recent research suggests that UVA-induced suppression of the skin's immune system and photoaging are associated with oxidative stress. Regardless of the cause, a weakened immune system is unable to recognize and destroy cancerous growths, thus leaving the skin defenseless against them.

  • UV rays of group A are always active, regardless of the season.
  • UV A is present everywhere, regardless of altitude or weather.
  • Group A UV rays penetrate glass - they can harm your skin even when you are driving or working in the office.
  • Group A UV rays are emitted not only by the sun, but also by other sources such as fluorescent lamps.
  • Group A UV rays are used in tanning beds.

Risks associated with exposure to UV group A rays:

  • Photosensitive reactions such as allergies and sun toxicity are most commonly caused by UV-A rays.
  • UV-A rays penetrate the skin twice as deep as UV-B rays.
  • Group A UV rays can cause corneal burns, cataracts and damage to the retina.
  • Most sunscreens block UV B rays but do not protect skin from UV A rays. Sunscreen Clinique Sun protects from UVA-andUVB-radiation.
  • Group A UV rays, unlike Group B UV rays, do not leave visible signs such as burns. And since there is no burn, many sunbathers experience a false sense of security and stay in the sun longer. The result is a longer exposure to Group A UV rays.

IPF

Immune Protection Factor - Immune protection factor.

In the future, IPF may become an indicator of the level of protection that a product will be able to provide to key elements of the skin's immune system following environmental stress.

It is still too early to speak of a scientific consensus on how IPF can be defined and measured.

IPF is an effective protection of Langerhans cells and other internal structures of the skin from solar radiation. Scientists are also studying the properties of antioxidants such as green tea, grapes and grape seed oil for further use as free radical scavengers.

Advice from David Orentrek, Clinique's Lead Dermatologist:

What factors should be taken into account when choosing sunscreen?

There are several such factors.

Skin type:If the sunscreen you use is irritating or inflamed, or you just don’t like the way it adheres to your skin, then you probably won’t use it at all. Try to find a product that works for you, even if it takes a while, and use it every day. Regardless of your skin type, it is recommended to use a broad spectrum of products, i.e. products that provide protection against UVA and UVB rays. If you have dry skin, then you can use a moisturizing product with sun protection factor (SPF) instead of sunscreen. If you have sensitive skin, do not use products that contain chemical sunscreens - they can irritate your skin. In such a case, it is best to protect the skin with a physical sunscreen, or apply a physically protective product underneath a chemical containing product.

For both light-skinned and dark-skinned patients, we recommend protecting their skin with at least SPF 15. While dark skin is inherently better protected from UV B rays (which cause burns), it is still exposed to hazardous UV A rays ( which can lead to skin cancer).

UV Intensity and Environment: SPF is calculated taking into account the time of exposure to sunlight. If you are planning long-term sun exposure, then you should use a product with a higher SPF. We also recommend using sunscreen products at high altitudes (because you are closer to the sun) or near reflective surfaces such as a swimming pool.

Hello Makeup Lovers. In this article we will talk about a hot topic during the holiday season - sun protection. It seems like everyone knows and understands that it is reckless to sunbathe is unhealthy, that the sun's rays can provoke terrible diseases, that every time you go out into the open sun, you need to use a cream with UV protection, but they still treat it somehow negligently ...

So let's go in order.

What is tanning?

Sunburn is a change in the pigmentation of our skin under the influence of ultraviolet rays due to the formation and accumulation of melanin pigment in the lower layers of the skin when exposed to the sun.

What is the beneficial effect of ultraviolet light on our body?

Under the influence of ultraviolet rays, the formation of vitamin D is activated, which is necessary for the body to absorb calcium and phosphorus, which are "responsible" for strengthening muscles and bones and for healing wounds.

Ultraviolet rays activate most of the processes occurring in the body - respiration, metabolism, blood circulation and the activity of the endocrine system.

Also, ultraviolet rays help to strengthen the skeletal system of the body.

Why is ultraviolet light dangerous for us? What are UVA and UVB?

There are two ranges of ultraviolet rays that we should protect ourselves from: UVA (alpha rays) and UVB (beta rays).

UVB radiation leads to burns, while UVA radiation leads to damage to the DNA structure and photoaging.

Group A ultraviolet rays:

  • active regardless of the season;
  • present everywhere, regardless of altitude or weather;
  • penetrate glass, plastic and clothing. Only white clothes are capable of reflecting ultraviolet A rays.

What is SPF?

SPF or Sun Protection Factor in English means sun protection factor.

There are products with different UV protection factors. Basically, there are factors 15, 20, 30, 50.

The protection factor does not mean the degree of protection of your skin from the effects of ultraviolet radiation, but the protection time that a product with the specified factor provides you.

  • SPF 15 provides approximately 93.5% protection against harmful UV rays;
  • SPF factor 20 - by 95%;
  • SPF factor 30 - by 96.7%;
  • SPF 50 - by 98% (this level of protection can only be achieved by adding chemical filters to the product with the specified protection factor).

How do you choose the protection factor you need?

In our climate, it can be said with almost 100% guarantee that we all burn out after 10 minutes of exposure to the sun without protection, so the formula for calculating the protection time is very simple and straightforward. See for yourself.

Protection time = SPF level * number of minutes in which you burn in the sun without protection

  • That is, the level of SPF 15 gives us protection for 150 minutes, with a burning time in the sun without protection, which is 10 minutes;
  • SPF level 30 - 300 minutes;
  • SPF level 40 - 400 minutes;
  • and an SPF level of 50 - 500 minutes.

After the specified time, the product with protection should be reapplied.

However, although SPF 50 in our example provides more than 8 hours of sun protection, it is recommended to reapply the product every 2-3 hours with continuous sun exposure.

And finally, I would like to talk a little about products that provide protection against ultraviolet rays.

Now on sale there is a huge number of products of various cosmetic brands from the mass market to luxury brands. Some products have similar compositions, some promise innovative ingredients. Some products are completely mineral, some smell like strawberries and are felt on the skin as whipped cream due to the presence of chemical elements in their composition.

However, there is one natural mineral (not chemistry or organic matter), the presence of which in cosmetic products with a sun protection factor is highly desirable - titanium dioxide. Particles of titanium dioxide reflect alpha and beta rays (UVA and UVB radiation) as a mirror. In the Russian Federation, this mineral is used, among other things, for coloring food products. Look for this mineral in a sunscreen product. However, remember that the composition of the product is always listed in descending order. That is, if titanium dioxide appears at the end of the list, its amount in the product is insignificant.

[Total Votes: 1 Average: 5/5]

Greetings to all lovers of reviews and cosmetics!ツ

My review is for those who already have pigmentation on the face and especially for those who do not. Why? Because no one told me in time about the consequences of ignoring the cream with protection from UVA and UVB rays.

Short background: Until the age of 25, I used creams from time to time, I did not worry about the need to use sunscreens at all. Until one day I went to the beautician. I addressed the problem of acne (at that time I had oily problem skin). But the beautician first of all drew my attention to the appearance of dark age spots.

And then I thought that tanning is cool, it's beautiful and I didn't suspect anything about photoaging.

Now: I'm 30+, normal skin type. I don’t go to solariums, in the summer I use sunscreen, I don’t sunbathe on vacation, I use SPF 50+ on the beaches. Decorative cosmetics for spring-summer I also buy with SPF.

I still haven't managed to get rid of pigmentation, but now I know how to prevent it and how to hide what is already there with the help of makeup.

Every spring I buy fresh cosmetics for sun protection. This season, I entrusted the protection of the skin to the Israeli cosmetics HolyLand (hereinafter abbreviated as HL)

Reinforced version of sunscreen with SPF 36. A wide spectrum chemical filter absorbs both UVA and UVB rays, and the visible part of the spectrum is neutralized by reflective elements

Sunbrella creams are used to prevent sunburn and premature skin aging due to sun exposure, for skin care during periods of active solar radiation.

This cream suited me, tk. contains filters and from UVA rays, UVB rays. I also need this protective cream after using acid products.

Compared prices in online stores. on average 1100-1200 rubles. (excluding shipping costs)

I found the most profitable option for 926.06r with free shipping!

What's happened UVA rays, UVB rays and what's the difference?

UVA rays -long waves ultraviolet radiation, 95% of them reach the Earth. They are present in our lives every day, all year round, from the moment the sun rises to its setting. Moreover, UVA rays come to us in any weather, in any climatic zone. This is why, although they are weaker than UVB rays, they can do more harm. They penetrate clouds, windows, and their penetration into the skin is deeper. Therefore, sunscreen is necessary even indoors and in any weather.

UVB rays
These are medium wavelengths of ultraviolet radiation. Only 5% of them reach the Earth's surface. Some of them are absorbed by clouds, and the other part - by the ozone layer. UVB rays are most active from 10 am to 4 pm. The only relief: they don't go through clouds and windows. But the bad news is that these rays are more powerful than long wavelengths (UVA) and can be quite harmful. This damage can be seen immediately - it is sunburn, as well as abnormal cell mutations and their development, and as a result - skin cancer.

Now about filters

- SPF filters- it is only protection against UVB rays. Most sunscreens have such filters.

- IPD and PPD Filters- it is protection against UVA rays (this is titanium dioxide, zinc oxide, Mexoryl, Tinosorb or Avebenzone).

PACKAGING, CONSISTENCE, COLOR, FRAGRANCE, COMPOSITION, etc.

Cream in a plastic tube 50 ml. The packaging was protected with foil.


The lid snaps into place. Cannot be unscrewed.


All information on the packaging is in Hebrew. Description in Russian can be found on the website. The composition is indicated in English.

The analysis of the composition satisfies me. I didn't dare to find a 100% organic sunscreen. Sunscreens have chemical filters!

Medium density cream. I can’t call the texture light, but it’s absolutely not oily texture. The color is the same white as in the photo, but the skin does not whiten, does not whiten, I will demonstrate below.


Smell. Standard creamy aroma. Reminiscent of the aroma of good old baby cream or something similar. Does not linger on the face.


I told everything about the cream in detail, if I missed something, ask, I answer the comments.

I want to show the cream in action. I have been using it since the beginning of spring and plan to use it until the end of summer.

Cleansed skin, no cream.


My most problematic place is my forehead. Uneven skin tone all year round.


In the spring, freckles appear under the eyes. Aesthetically, they don't bother me.


On cleansed skin, I apply cream before applying makeup. It doesn't matter if it's sunny outside or cloudy.

Mode of application:

Apply the cream to the face and open areas of the body for 20 minutes. before going outside, apply additionally every 3-4 hours. And also after swimming.

I apply the cream abundantly. It is well absorbed and does not whiten the skin. Does not affect pore clogging and oily sheen.


Comparison BEFORE applying cream and AFTER cream. There is no difference in the photo! But the effect of the cream is felt:

  • moisturizes the skin
  • the skin becomes firmer and tighter
  • slightly mattifies the skin (I think because of the zinc content in the composition)


I'll tell you how I disguise dark spots and at the same time I will show you how the tonal coating on the sunscreen HL Sunbrella behaves.

Immediately after applying HL Sunbrella, I apply a light foundation with a beauty blender.

  • foundation does not affect
  • does not fall into pores
  • does not slip

in one sentence - HL Sunbrella is also an excellent make-up base


How to mask age spots for your face? My personal experience, by trial and error. I'm not a makeup artist. But for myself I made the following conclusions:

  • no need to try to cover up age spots with a thick layer of foundation, it is better to use a light coating with reflective particles
  • it is better to choose a tone with a yellow undertone (in the presence of dark age spots)
  • well evens skin tone sculptor, bronzer and blush with reflective particles

Photo comparison. Left: foundation... Right: foundation + using a sculpting palette

Photo # 16 HL Sunbrella cream does not conflict with makeup

Conclusion: Of course, it is better to take care in advance to protect the skin from the sun's rays. Especially if there are moles on the face. In my case, sunscreens help prevent pigmentation increase.

Such creams do not get rid of existing age spots. Can help salon procedures(which ones should be selected by a specialist). I did the peeling in the salon (course) - it did not help. Perhaps I'll try some hardware procedures later.

Again! It is necessary to use sunscreen even if there are no visible changes on the skin. This will help prevent their occurrence.

If pigmentation has already appeared, sunscreen will help prevent its spread, and only cosmetics can mask pigmentation!

For me sunscreen HL Sunbrella so far the best I've ever used. That's why:

✔ contains filters and from UVA rays, UVB rays

✔ does not conflict with foundation

✔ does not clog pores

✔ invisible on the skin

✔ mattifies the skin


Thank you for your attention to your review and happy shopping!

07 May 2017

Elena Stepanova, Expert of the site SweetZagar

Hardly a child has heard about the harmful effects of ultraviolet radiation. Therefore, with the arrival of sunny days, every woman who is accustomed to caring for herself stocks up sunscreen and lotions. But such foresight does not always help to avoid the sad consequences of long exposure to the sun. In order to choose the right cosmetic product with, it is not enough to look at its indicator - it is best to evaluate the composition yourself, knowing what components are needed in a particular situation.

Such multifaceted ultraviolet

Depending on the wavelength and biological activity, it is customary to distinguish three types of ultraviolet rays:

  • UVA(320-400 nm) are long-wavelength rays and make up 95% of all ultraviolet radiation.
  • UVB have an average wavelength of 290 - 320 nm.
  • UVC are too short to penetrate the atmosphere, and therefore absolutely not dangerous to humans.

And although ultraviolet B rays make up only 5% of the total that reaches the Earth's surface, they are the most aggressive. The most sensitive to UVB rays are:

  • light-skinned owners and appearance;
  • small children in whom the natural synthesis of melanin is not yet fully formed;
  • sunbathers, whose body is decorated with a large number of moles and age spots;
  • sunbathers who are undergoing antibiotic therapy with drugs that cause photosensitization (for example, doxycycline, tetracycline and their derivatives);
  • patients who did not have time to recover from plastic surgery and some cosmetic procedures (chemical skin whitening, deep peeling, laser resurfacing and etc.).

Some of the UVB energy is filtered by clouds and window glass, but on a cloudless sunny day, their effect is maximized. The highest activity of the B-spectrum is observed from 10:00 to 16:00- it is at this time that the tan lays down most intensively, but the risk of getting sunburn increases significantly.

The benefits and harms of UVB rays

It is the B-spectrum of ultraviolet radiation that is responsible for obtaining the desired bronze tan. These rays act on the surface layers of the epidermis, stimulating hyperpigmentation in cells. In addition, UVB stimulates the natural production of vitamin D to a greater extent, which is vital for every body. However, these positive properties of ultraviolet radiation are associated with a negative effect that it has on humans.

The harmful effects of ultraviolet B spectrum are hard to miss. Literally after a few minutes (the duration may vary depending on the skin phototype, but in most cases it does not exceed half an hour), the unprotected skin begins to gradually redden and become inflamed. If the irradiation is stopped by going into the shade, the redness will disappear after 2-3 days, but the aggravation of sunburn is fraught with serious consequences. Painful blisters caused by UVB heal for a very long time, and the skin is completely restored in the best case in a few months. Therefore, going outside without sunscreen on a fine day is not only reckless, but also very dangerous!

Cosmetic UVB filters

Modern cosmetics designed to protect the skin from negative impact ultraviolet radiation, while retaining the positive effect of its effects, contain special substances that block up to 99% of aggressive UVB rays. Mineral filters, which are called physical filters in cosmetology, reflect medium wavelengths of light, thereby preventing sunburn and inflammation. Substances in this group include:

  • titanium dioxide;
  • zinc oxide.

Each of these components is absolutely safe for the skin, which is why they are preferred by many cosmetic brands. True, there is a small "but": titanium dioxide can whiten the skin a little, so a large amount of it is contraindicated for people who are naturally dark or who have already significantly sunburned. For them, the best choice would be sunscreen products containing zinc oxide - it does not leave any marks on the skin.

In addition, chemical filters can partially neutralize UVB rays - they penetrate into the deep layers of the skin and turn harmful ultraviolet into thermal energy... Each of them is effective in its range:

  1. Benzoate-4 methylbenzylidene camphor (Parsol 5000) neutralizes UVB rays with a length of 290-300 nm;
  2. Benzophenone-3 (Oxybenzone) is effective against rays up to 350 nm;
  3. Benzophenone-4 (Sulisobenzone) acts on ultraviolet light with a length of 260375 nm;
  4. Benzophenone-8 targets 250-390 nm beams;
  5. Ethylhexyl triazone protects against UV spectrum 290-320 nm;
  6. Mexoryl XL combats 290-400 nm radiation;
  7. Para-aminobenzoic acid acts on UVB lengths of 290-313 nm;
  8. Ocinoxate effectively destroys the entire B-spectrum.

This list is far from complete - the substances have dozens of modifications, and every month leading dermatologists present new, more and more safe and perfect components that can protect the skin from the harmful effects of ultraviolet radiation.

How to protect yourself on a sunny day?

To a large extent, the SPF index indicated on each tube of sunscreen cosmetics reflects the degree of protection from UVB. However, this does not mean that special A-spectrum filters can be neglected - the harmful effects of UVA rays also affect the condition of the skin.

Only professional cosmetics, harmoniously combining universal filtering components, can provide the skin with maximum care and care on a sunny day. Armed with one of the world's leading brands of sunscreens in the field of cosmetology -, etc. - you can be sure: sunburn, dry skin and its premature aging You are not threatened!

We will tell you as much as possible about UVB radiation. About the dangers of UVB rays. About correct protection.

About such a concept as ultraviolet radiation, probably everyone knows. These are well-known UV rays, which, when in contact with surfaces for a long time, do terrible things, for example, they cause paint to fade or burn the skin. The effect of ultraviolet radiation on the skin is unequivocally irreversible aging. Moreover, aging is not in the usual sense, that is, age-related (or chrono-aging). It's about photoaging.

What are UVA, UVB and UVC rays and how do they affect our skin?

Studying the phenomenon of "solar activity", scientists often use terms such as cosmic radiation, galactic and cosmic radiation. They all touch the rays that our Sun emits and that hit our planet. A huge part of the radiation is reflected by the ozone layer, glaciers, but some of it still penetrates the atmosphere, reaching the surface of the earth. Fortunately for all life on the planet, this part is negligible compared to what originally came from the Sun. In addition, UV rays that penetrate the atmosphere are still retained in large quantities by oxygen, which absorbs them, turning into ozone.

The rest that hits the ground is an uneven stream, consisting of several separate waves. First of all, ultraviolet radiation is electromagnetic radiation, so its rays have different lengths waves in the range from 10 to 400 nm. Next comes the division of the rays into 4 groups depending on the wavelength:

... the shortest rays are called extreme ultraviolet (10-121 nm), which is abbreviated as EUV / XUV;

... far range - shortwave ultraviolet (120-280 nm) or UVC;

... medium range - medium-wave ultraviolet (280-315 nm) or UVB;

... near range - long-wave ultraviolet (315-400 nm) or UVA.

Extreme and short-wave ultraviolet light is completely absorbed by the earth's atmosphere, so humans do not need protection from EUV and UVC. UVB rays are 90% absorbed by the atmosphere, but UVA rays almost completely reach the Earth's surface. Actually, therefore, modern cosmetology offers protection against two types of radiation, with the emphasis on protection against UVA rays.

Since UVA and UVB have different radiation intensities, this means that they have different rates of destruction of what they hit. UV rays in direct contact with the surface cause it degradation, this also applies to our skin. Ultraviolet radiation has a fraction of radiation, therefore, it is necessary to defend against it, so as not to earn at least sunburn. The shorter the wavelength of the rays, the more dangerous the radiation. Those few UVB rays that reach the ground negatively affect DNA and are responsible for cell mutation, including can provoke growth cancerous tumors... UVA rays are not so “toxic”, slightly less dangerous, but they make up 90% of the ultraviolet radiation that hits the surface, and they are responsible for photoaging. The phenomenon of reflection from surfaces makes them even more dangerous, which makes it possible to double the radiation dose. During continuous and prolonged exposure to UVA rays, skin atrophy, the level of collagen in the matrix decreases and cell turnover decreases. Fortunately, you can avoid photoaging by using sunscreen to protect yourself from the rays.