The meaning of UVA and UVB indicates two types of ultraviolet rays. UV is short for ultraviolet, electromagnetic radiation, and these rays of light are emitted by the sun and are invisible to the human eyes.
The ultraviolet rays (UV), even invisible, have an effect on the skin of the human being, even though these rays represent only 5% of the solar radiation that reaches the planet, and are present at any time of year, being that – obviously – the incidence is higher in the warmer seasons, but this does not mean that you should not take care of the skin during the cold seasons.
If a person has a prolonged exposure to the ultraviolet rays, it will be prone to develop several ailments to the health, being that the parent is the cancer of the skin.
For this to be avoided, it is important to prevent the radiation through the recommendations to use sunscreen daily with spf protection high and avoid the zones with highest peak of sun. The protection factor (SPF) should be used by all people, regardless of age or skin color.
The largest natural filter of ultraviolet radiation is the ozone layer, located approximately 30 km of the earth’s surface, can be filtered by this layer, making only an appropriate amount of radiation arrives on the surface, ensuring that life on Earth is possible.
Meaning of UVA
Standing for Ultraviolet A, the UVA rays penetrate the deep layers of the skin and it is this radiation that, although it is present throughout the year, it is more intense before 10 am and after 16 pm.
The UVA rays may seem harmless, especially for providing a tan more beautiful, they are responsible for the aging of the cells of the epidermis (wrinkles, loss of elasticity and patches of skin are consequences), causing also allergies solar and predisposition to the onset of skin cancer, among other irreversible damage.
The UVA rays also are those rays used in artificial tanning chambers.
Meaning of UVB
Short for Ultraviolet B, the UVB radiation is auqela that is prevalent among the 10 hours of the morning until 16 o’clock in the afternoon, being more intense during the warm seasons, thanks to the high temperatures.
This radiation penetrates the surface skin, or is, only affects the layers the most superficial of the skin, which can cause sunburn and redness. Even though a large part of the UVB radiation is absorbed by the atmospheric layer of the planet, the rays remaining are harmful to the human being. The redness and burns will appear after the bath or at night, as the radiation intensifies after a few hours after the exposure to the sun.
It is worth remembering that the rays UVB rays are responsible for the lesions pre-cancer, and also by the skin cancer not melanoma.
In addition to these two types of radiation, there is radiation UVC. This is highly penetrating and harmful to health, however, she is totally absorbed by oxygen and ozone of the atmosphere and does not reach human beings – it is for this reason that it is crucial campaigns of the protection of the ozone layer, so that these rays do not reach the surface of the planet. It is quite likely that a large part of living things would be threatened if this radiation UVC to reach the surface in the relevant quantity.
UVC has utility in the sterilization of surgical instruments and the water, through artificial sources.