By David Buice and Stephanie A. Savory, MD
What is UV radiation?
UV radiation is part of the electromagnetic (light) spectrum reaching the earth from the sun. UV radiation has wavelengths shorter than those emitted by visible light and is invisible to the naked eye.
The wavelengths of UV radiation are classified as UVA, UVB, or UVC. UVA wavelengths are the longest, followed by UVB and UVC.
As they travel through space, the earth’s ozone layer absorbs all UVC and some UVB rays, meaning most of the UV rays that contact you are UVA, with a smaller amount of UVB.
How does UV radiation affect me?
Both UVA and UVB can damage your skin and cause skin cancer. UVA penetrates the skin deeply, and contributes to skin aging and wrinkling. It is thought to play a role in some skin cancers. UVA rays can penetrate both clouds and glass, and most tanning beds give off large amounts of UVA.
UVB rays, while easily blocked by glass, are the main cause of sunburn. They’re also thought to cause most skin cancers.
While it’s true that UVB helps the skin produce essential vitamin D, the American Academy of Dermatology recommends diet and vitamin D supplements over sun exposure.
How common is skin cancer?
At least one million Americans are diagnosed with some form of skin cancer each year. According to the American Cancer Society, every hour of every day, one American succumbs to melanoma, the deadliest form of skin cancer.
How can I prevent UV overexposure?
To reduce the risk, stay away from tanning beds and minimize outdoor activities during the most sun-intense times, 10 AM to 4 PM. Wear a wide-brimmed hat and sun-protective clothing. Also use ample amounts of broad-spectrum sunscreen protecting against both UVA and UVB, with a sun protective factor (SPF) of at least 30, and reapply every 2 to 3 hours.
Finally, if you see anything suspicious on your skin, make an appointment with your dermatologist immediately.
