It's a common myth: during the winter months when the sun's rays are not as strong you don't need sunscreen. But it is just that; a myth. To understand why, you first need to understand the difference between UVA and UVB rays.
UVB rays are middle-range sun rays. This type of ultraviolet ray is responsible for tanning, sunburns and premature aging of skin. Too much exposure to UVB rays can contribute to developing skin cancer. The SPF in sunscreen relates to how much protection you receive from UVB rays.
UVA rays are long-range sun rays. These types of rays penetrate deeper into your skin and is thought to play a role in premature aging of your skin and wrinkles. It is also thought to cause skin cancer.
Another key difference between the two types of sunlight is when you are most at risk. UVB rays are strongest in the summer months, between the hours of 10:00 AM and 4:00 PM. UVA rays, however, are present all year round during the daylight hours meaning that even in the dead of winter, if you are outside, you are exposed to UVA rays. These types of rays are still around on cloudy days and can even penetrate glass.
The Importance of the Right Sunscreen
Many people choose a sunscreen based on the SPF rating aalone. It is thought that the higher the number, the better the protection (however some research indicates that anything over an SPF of 30 doesn't give additional protection). But the SPF in your sunscreen is only part of the solution. SPF rates how well it protects against UVB rays, not UVA rays.
How well your sunscreen protects you from exposure to UVA rays depends on the ingredients. The FDA has approved the following ingredients as protection from UVA:
- Avobenzone (Parson 17890
- Zinc oxide
- Ecamsule (Mexoryl)
- Titanium Dioxide
Your sunscreen should contain at least one of these ingredients. Many sunscreen manufacturers have "multispectrum protection," "broad-spectrum protection," or "UVA/UVB protection" written on the bottle to make it clear that it works to protect you from both types of dangerous rays.
Sun Protection Indoors
As previously mentioned, UVB rays do not penetrate glass, however UVA rays do. Car windows are thought to let in 60 percent of UVA rays and even indoors, if you are near a window, you are at risk. A report in Clinical Interventions in Aging looked at 10 men and women who showed significant aging on one side of their face: wrinkles, brown spots and sagging. All worked indoors and showed significant aging of their skin on the side of the face closest to a window. While you won't get a sunburn from sitting indoors by a window, you are still causing damage to your skin.
Sun Protection During the Winter
- Applying a broad-spectrum sunscreen with an SPF of 30 everyday, whether you will be inside or outdoors, is important.
- Remember that snow reflects the sun's rays so you are effectively getting a "double whammy" with the sun's rays hitting you from above and below.
- Just as in summertime, sunscreen should be reapplied every 2 hours or if you have been sweating.
- UV blocking sunglasses are just as important during the winter as during the summer.
- Continue to wear wide brimmed hats and using gloves to protect your face and hands.
"Shining Light on Ultraviolet Radiation," Date Unknown, Staff Writer, Skin Cancer Foundation
"UVA Radiation: A Danger Outdoors and Indoors," Date Unknown, Staff Writer, Skin Cancer Foundation