UV stands for ultraviolet light. It is a form of electromagnetic radiation produced as part of the light spectrum by the sun. There are three forms of the radiation, known as UVA, UVB and UVC. Of these three, we are most exposed to UVA radiation. The atmosphere of our planet blocks nearly all of the other two spectrums, which is a good thing since UVA is the weakest of the three forms of radiation.
For most people, the dose of ultraviolet light on an average day is actually quite small, but the effects can add up over time. This is particularly true if you actively seek out the sun through sun bathing and such. Over time, UVA radiation acts upon the collagen in the epidermis of your skin. It does not cause a sunburn, but it penetrates deeply into the layers of the skin and causes damage. The damage can include premature aging of the skin, DNA damage that can result in mutations and possible skin cancer. Because of this, it is vital that you use sun block that is oriented to provide protection against UVA. Most sun blocks are tailored to UVB protection, which simply is not enough protection.
The human body has a natural method of protecting itself from the effects of ultraviolet radiation. You probably already know what it is ? tanning. When you tan, your skin color turns to a darker brown shade. The body accomplishes this by producing melanin in the skin, the functional cause of the change of color. The more melanin produced, the darker your skin turns and the more protection there is against ultraviolet light penetration.
So, do you want to block all ultraviolet light from your skin? Oddly, the answer is no. The reason has to do with how your body processes ultraviolet. In nominal amounts, the UV light is actually beneficial because the body uses it to produce Vitamin D. Without Vitamin D, you can develop Rickets or other problems with the strength of your bones.
At the end of the day, getting outdoors is a good thing. It is wise, however, to use a sun block that will protect you from ultraviolet radiation.
