Right now, someone reading this post is saying, “...but we need to get in the sun for our bodies to make vitamin D.” That’s true, but most of us exceed the amount of sun exposure necessary for the generation of sufficient vitamin D. Besides the visible spectrum of light, sunlight contains three types of ultraviolet light; “A”, “B” and “C”. It’s the UV light that is cause for concern.
UVA accelerates skin aging and wrinkling and contribute to skin cancer, such as melanoma. Nothing in our Earth’s atmosphere will block UVA, unfortunately, they make up the majority of our sun exposure. For those of you who insist on baking yourself in a UVA tanning bed - a UVA tan does not help protect the skin from further sun damage; it merely produces color and a false sense of protection from the sun.
UVB rays are also dangerous, causing sunburns, cataracts – a clouding of the lens in your eye – and even immune system damage. UVB is also a factor in skin cancer. Melanoma, the most dangerous form of skin cancer, is thought to be associated with severe UVB sunburns that occur before the age of 20. Most UVB rays are absorbed by our Earth’s atmosphere, but enough can still reach the ground to cause serious damage.
UVC is the most dangerous, but fortunately, these rays are blocked by our Earth’s atmosphere and don't reach the earth.
What's important is to simply know that there is no such thing has a "healthy" tan. It may be a sign of sun damage. The risk of damage increases with the amount and intensity of exposure. Those who are chronically exposed to the sun, such as farmers, boaters, and sunbathers, are at much greater risk.
Employ the “SLIP, SLAP, SLOP” rule when out in the sun: Slip on a shirt, Slap on a hat, and Slop on the sun screen.