The Facts about UV Rays
by Staff Writer
If you're concerned about the health of your skin and reducing your risk of skin cancer, knowing more about ultraviolet energy is key. Studies have found that having a better understanding of how the sun damages the skin and why protection matters leads to improved sun care among both men and women, so read on to get the facts about UV.
1. Ultraviolet energy actually consists of different categories of light: ultraviolet A or UVA, ultraviolet B or UVB and ultraviolet C or UVC. The types are categorized by the length of their waves.
2. UVA is the longest type of ultraviolet light. About 95 percent of the ultraviolet energy to which we are exposed is UVA. The long length of its waves allows UVA to move past the upper layer of skin, so the damage that it causes occurs in the middle layer of tissue.
3. UVC is very short. Most of it does not reach the Earth's surface. As a result, sunscreen products typically do not provide protection against UVC.
4. UVB has longer waves than UVC and shorter waves than UVA. More intense than UVA, the energy of UVB is concentrated on the outer layer of skin because it cannot penetrate as deeply as UVA.
5. UVB is the type of ultraviolet that causes sunburn. UVA has been identified as the primary source of photo-damage to the skin, which gives rise to imperfections like wrinkles and age spots.
6. UVA and UVB rays both raise the risk of skin cancer. Around 86 percent of melanoma, the most deadly type of skin cancer, is due to ultraviolet exposure. UV causes roughly 90 percent of all other types of skin cancers.
7. The SPF factor of a sunscreen indicates how much UVB the product absorbs or reflects. It does not measure UVA protection. Only sunscreens labeled as "broad-spectrum" protect the skin from UVA.
8. Ultraviolet energy is present even when it's not sunny. As much as 40 percent of UV will still penetrate the atmosphere on cloudy days.
9. Snow intensifies the effect of ultraviolet energy. Up to 80 percent of UV is reflected by snow, exposing the skin to the energy from two sources: overhead and on the ground.
10. Ultraviolet energy is the most intense between the hours of 10AM to 4PM, but it is present whenever the sun is up.
11. When the Earth is tilted toward the sun during the spring and summer months, ultraviolet energy is most intense. This makes the months of April to August the worst times for sun exposure.
12. Ultraviolet light intensity increases at higher elevations at a rate of roughly 4 to 5 percent for every 1,000 feet.
13. UV can also damage the eyes. Sunglasses with UV protection can decrease the risk of sun damage.
To reduce your risk of UV damage, it's important that you use sunscreen every time you'll be outdoors. Apply at least 1 ounce for full body coverage and at least 1 teaspoon if only your face will be exposed and reapply every 2 hours at a minimum to keep your sun protection going strong. Using a sunscreen of SPF 15 or higher on a daily basis is shown to lower the risk of skin cancer by 40 to 50 percent, so don't leave home without sun protection!