In the era of coronavirus pandemic, most of us hid in our safe homes. For weeks, we spent time with family, not leaving our homes. This certainly gave us protection from COVID-19. At the same time, however, disease entities emerged that had not previously affected such a wide social group or were even completely unknown to us. We heard about mask acne, eczema, and dry skin on our hands caused by wearing rubber gloves and using antibacterial gels with high alcohol content. Staying indoors also put us at risk for vitamin D deficiency.
As we know Vitamin D is synthesized by the skin when exposed to light. According to research, it is enough to expose about 18% of the body (hands, forearms, calves) for about 15 minutes a day to provide the necessary amount of the vitamin to the body. Therefore, outdoor movement is necessary for health.
However, as it usually is in the life, there is another side to the coin. Too much skin exposure to the sun can cause sunburn, irritation, allergies and even cancer. Therefore, it is important to protect your skin from the sun's rays. And most importantly, the use of creams with sunscreen, even the highest, does not block the mechanisms of synthesis of vitamin D in the skin!
Solar radiation
We can divide ultraviolet radiation into three ranges of the wave spectrum:
UV-C (100-280nm) This is a very short wavelength but has the highest energy. It does not reach the surface of the Earth because it is absorbed by the ozone layer of the atmosphere. If it were not, UV-C radiation would kill living organisms. Light used, among other things, in germicidal lamps to decontaminate equipment and rooms.
UV-B (280-320nm) Much of the radiation is stopped by the Earth's atmosphere. It accounts for only 4-5% of the UV radiation reaching the earth. UVB is responsible for delayed tanning. Melanin (pigment contained in the skin) is not produced until after 48-72 hours. So the tan develops later, but - importantly - it stays for longer. It is mostly absorbed by the stratum corneum, only a small amount penetrates the dermis. UV-B radiation has strong erythematogenic properties and can cause sunburn of the epidermis and dangerous damage to skin cells. But most importantly it is responsible for the production of vitamin D3. However, prolonged exposure can cause skin cancer.
UV-A (320-400 nm) Wave intensity is the same throughout the day, regardless of weather and season. UV-A rays have the ability to penetrate clouds, glass and the human epidermis. It makes up to 95% of UV radiation reaching the earth. It is responsible for the formation of an instant tan. It is visible after a short time of tanning but lasts only a few hours. UV-A radiation does not cause sunburn, which is apparently safe.However, nothing could be further from the truth. The wave penetrates deep and reaches the dermis. Under its influence invisible changes appear in cellular DNA. The effect of radiation is cumulative and causes photoaging of the skin.
Blue Light
Blue light (400-500nm) is the shortest wavelength in the visible spectrum. Blue light is emitted by the screens of phones, smartphones, tablets and televisions. In other words, all those devices that are associated with LED sources. As vitamin D deficiency is the result of a deficit of exposure to the sun, blue light is associated with an excess of light exposure on the skin. Every day we are exposed to blue light for many hours because electronic devices surround us from all sides. They replace books, newspapers and even direct contact with other people. Blue light generates a similar amount of free radicals as UV-A and UV-B radiation combined. It penetrates into deeper skin layers than UV radiation. It causes shortening of the life span and proliferation of fibroblasts. It can also cause DNA damage and premature skin aging. Blue light penetrates deep into the skin and has destructive properties in all layers. It induces oxidative stress, weakens the epidermal barrier, causes discoloration and leads to premature skin aging.
Photoaging of the skin
Overexposure to the sun's rays can cause photoaging of the skin. The effects are noticeable in every layer of our skin. In the epidermis, there is a noticeable reduction in the thickness of the spinous and granular layers, while the stratum corneum becomes visibly thickened.
Melanocytes clump together causing pigment spots and discoloration. The skin also becomes dry as a result of disrupted NMF production. The skin is less resistant and more prone to irritation and allergies.
In the dermis, the activity of fibroblasts decreases, thus reducing the synthesis of collagen, elastin and hyaluronic acid. The water binding capacity also decreases. The network of blood vessels also changes. Some of them disappear, causing deterioration of nutrition and oxygenation of cells. Teleangiectasias also appear.
The density of fat tissue in the subcutaneous layer decreases. In addition, numerous wrinkles and furrows appear.
