Sunbathing, UV rays and solarium

LIGHT is on part of electromagnetic spectrum. Solar energy spectrum forming from UV rays 10% ,visible light rays 50% and infrared rays 40%. The ozone layer blocks ultraviolet radiation below 290 nm, so UVC rays reach the ground little. Geophysical interest are the so-called ozone holes, which increases the amount of UV radiation reaching the ground.

UVC light calls forth the human skin reddening, which is visible in about 6 hours. Skin also can start to pigmented. UVC rays are absorbed completely in the window glass.

UVB light causes skin 12 to 24 hours after so called sunburn and 48 to 72 causes pigmentation. UVB rays well through by water (caution in swimming) and absorb in window glass. They are called intermediate which has the effect of 7-dehydroxycholesterol is biologically active and becomes vit.3D. It has  negative impact on epidermis connective tissue and blood vessels (DNA, RNA, changes in the proteins and cell membranes).

UVA light in small dose does not induce pigmentation or skin redness and does not irritate eyes. High dose causing immediate erythema and pigmentation. Along with the intensive UVB rays causes skin redness. Passes through the glass and penetrates the skin, cells can induce DNA damage and immunomodulation (change of the protection) and increase the risk of pigmentation changes and malignization.

Under the influence of UV radiation in the skin is reduced number of Langerhands cells, it increases the sensitivity to various allergens, including tumor cell antigens. There will be mutation of 53 chromosome, which is also prickle skin cancer carcinogen. Rises the skin cancer aggressiveness. Radiation changes occur in the walls of capillaries, along with the Langerhans cells, these changes cause a change in the DNA thymine and pyrimidine. Thymine will contribute to the development of skin malignancies. The effect of UV rays in the cell of DNA photo reactivation then move to unscheduled DNA synthesis and finally formation of two straight intact molecule dubbed genesis.

UV rays on human skin depends on the following factors:

1.skin type

2.rays from the cumulation

3.the intensity of the rays

4.sunbathing during childhood

5.place of residence

 

Types of human skin, after 30 min. sunbathing

I UV rays, there is always burn, never browning

II UV rays occurs usually burns, sometimes below average browning

III UV occasionally there will always be burning rays and medium browning

IV UV rays do not cause burns, and always there will be average intense browning

V people with black skin-mexicans, indians, mediterranean

VI negroes

The most vulnerable to the UV rays are people with I and II skin type, which are red-headed, blue-eyed, light skinned people as well as the people who work long hours in the sun (sailors). Reflected in the reduction of sunburn in childhood so called freckles (damage of DNA cells) sunburn occurs approximately 4 hours after sunbathing and lasts 8-24 hours, skin turns red, sometimes swelling and sometimes vesicles. Later the skin peels off. Repeated sunburn is a risk factor for melanoma and skin cancer. Chronic sun exposure occures dermatoheliosis, that causes skin wrinkling, mottled pigmentation, thickness, teleangiectasia, skin relaxation and in atrophy.

Skin pigmentation occures through the stimulation of melanocytes. In the time of direct pigmentation UVA rays will cause pigmentation at the time of activity or shortly after. In most cases, there will be copper or coffee brown colour pigmentation. At cosmetic purpose of experiencing such skin pigmentation in tanning salons. Direct pigmentation often disappears after few minutes to a few hours after the radiation, the pigment melanin oxidation occurs biochemically. Indirect pigmentation occures 24 to 72 hours (and in particular strong rays of the pigmented wavelenght are ~ 297nm).Pigmentation remain here for days and weeks. The formation of melanin depends upon of indirect pigmentation (the number of melanosomes) and hormonal factors (beta-MSH, melanocyte-stimulating hormone).

It has been established that the photo augmentation (expansion of the light) is caused so called sunburn cells formation. Sunlight-induced skin thickening persists for weeks and disappears in the winter period.

Solar radiation to the normal skin can be:

1.Acute (sunburn, temporary pigmentation, permanent pigmentation, so called melanisation, photo augmentation.

2.Chronic (photo thickening, skin inflammations, elastosis e.-actinic elastosis, precancerous conditions e-actinic keratosis, malignant lentigo and malignant tumors.

Radiation significant changes in the skin when exposed part of the connective tissue, collagen degeneration occurs and abnormal elastolysis (increases the number of fibroplasts RNA gelatinase).It is believed that the gelatinase contributes to photoagening.

Sunburn is recommended to protect with protective cream factor of 30 and more, sunscreens and clothing made of natural silk. When you go to sunbathe should know that the absorption of radiation in the skin is most active from 11.00 to 15.00, the year-round tropical countries and the cloudy and cold weather. For cosmetic purpose for skin pigmentation are used UVA SUN 2000, 3000 and 5000 light and  Mutzhas lights. UVA radiation varies by a factor 3 (13,5 mW/cm 2) UVB radiation is a factor of 60 (19,2 mikroW/cm. 2) and a blue light it is 2,5 (2,5 mW/ cm 2). Studies have shown that these factors are in tanning salons in the range 18 to 45 mW/cm2. Solarium are similar in terms of normal sunlight, UVB rays, but these are much higher in the schale of UVA rays (index 13). In comparison, for the usual tanning sunny Mediterranean latitudes noon UV index is 8,5!

Old solarium lamps also emit UVA and UVB rays, which is why they are no longer recommended for use. Nowdays, it has been established that a high amount of UVA rays can cause malignancy in the skin and it is know that many of dermatoses are associated either directly or indirectly by UV radiation from phototoxic and photoallergic reactions and in the end skin elastosis, with carcinomas and melanoma.

Therefore it is advisable, before to go sunbathe or visit solariums think about the truth — first think then act! (beauty always requires sacrifices!)

 

---