What are ultraviolet rays?
In physics, ultraviolet radiation is an interval of electromagnetic radiation, belonging to the electromagnetic spectrum, with a wavelength immediately shorter than the light visible to the human eye and immediately higher than that of X rays.
Essential to the synthesis of vitamin D which fixes calcium in the bones and plays a fundamental role in the structure of the epidermis. They help us in tanning. They are responsible for sunstroke and can cause mutations in the structure of cells.
Ultraviolet radiation constitutes about 10% of the light emitted by the Sun and is also produced by ionized gases and particular lamps (mercury vapor lamps and Wood's lamps). At high wavelengths it can cause chemical reactions, such as glows or fluorescence phenomena.
- Negative effects: as a result of excessive exposure of the skin to the sun, they can induce the onset of tumors; they break collagen bridges and damage capillaries, triggering premature aging. UVA rays represent 95% of the UV radiation that reaches Earth.
Ultraviolet rays are electromagnetic radiation emitted by the Sun, whose wavelengths are immediately lower than those of visible light. They are called this, in fact, because they are “beyond violet”, the last color perceived by the human eye in the spectrum of visible light.
UV-C rays are the most dangerous ultraviolet rays and have a wavelength of 100 - 280 nm. UV-C rays are particularly harmful to health as they have a high carcinogenic power. Fortunately, they are retained by the ozone layer and therefore have no particular effect on the skin.
Ultraviolet rays are electromagnetic radiation of a wavelength between 100-400 nm (nanometers = billionth of a meter) and are the most energetic non-ionizing radiation.
The ultraviolet (UV) rays emitted by tanning lamps (and the sun) can cause degeneration of skin cells, which can result in premature aging of the skin, with the appearance of wrinkles and spots and sometimes even tumors such as melanoma.
The first group includes erythema (skin redness due to vasodilation), edema (swelling due to the leakage of fluid from the capillaries), blisters and scaliness (solar radiation stimulates the proliferation of keratinocytes, with a consequent increase in desquamation cutaneous).
UVB rays, on the other hand, act at a more superficial level by activating melanogenesis, that is, the production of melanin, responsible for our tanning. Not only that: they are also responsible for sunburn, and other more serious skin conditions.
Solar radiation is the radiant energy emitted by the Sun in interplanetary space, generated starting from the thermonuclear fusion reactions that occur in the solar core and which produce electromagnetic radiation at various frequencies or wavelengths, which then propagate in space at speed ...
UVA and UVB rays are harmful to the skin and eyes. Here are some rules to minimize the risks of UV rays.
The UV-C rays emitted by the sun do not reach the earth's surface, while 90 percent of UV-B rays are absorbed by the ozone layer and the rest of the atmosphere.
The eyes must be protected with sunglasses. It is important that sunglasses provide good protection from ultraviolet radiation, this is guaranteed by the wording on the package "Block 99% of ultraviolet rays".
Premature Aging and Wrinkles: Ultraviolet radiation can cause permanent damage to cells, causing deeper wrinkles and blemishes to form and loss of elasticity due to free radical activity and less collagen.
Positive effects of UV
These radiations play an important role in the organic synthesis of vitamin D, a substance involved in the development of the skeleton and capable of protecting the bones from diseases such as rickets, osteomalacia and osteoporosis.
- Wear ultraviolet protective fabrics. ...
- Avoid, if possible, the central hours of the day.
- Use good quality sunscreens, preferably purchased at a pharmacy.
X-rays, gamma rays, alpha particles and beta particles are part of ionizing radiation. Even a limited portion of ultraviolet rays (those closest in wavelength to X-rays, coming from the Sun or other sources) have ionizing properties.
To protect yourself from the sun, there are not only protective creams. ... sunglasses, with lenses that protect against at least 99 percent of UV-A and UV-B rays, a concept that can also be expressed in the label as the absorption of solar radiation up to 400 nm wavelength .