UV Rays

Everyone at one point or another has heard about ultraviolet (UV) rays and their potential to harm our skin. What are UV rays, and why should they concern you?

According to the Skin Cancer Foundation, UV radiation is made up of three different wavelengths: UVA, UVB, and UVC. UVA and UVB rays are the harmful ones in the trio. Although UVA rays aren’t as likely to cause a sunburn as UVB rays, they penetrate the skin more deeply. They are not effectively blocked by traditional sunscreens and can even pass through windows. Studies have shown that the cumulative effects of UVA rays may not be immediately noticeable, but they can have damaging consequences over time, including skin aging and the development of cancer. UVB rays, which also contribute to skin aging and cancer, are the source of short-term effects like sunburn, and traditional sunscreens are quite effective at blocking UVB rays.

The sun protection factor (SPF) indicates the amount of UVB exposure it would take to get sunburned with sunscreen versus without sunscreen. Here is one example: someone who would burn after 10 minutes without sunscreen would expect to be protected for 100 minutes with an SPF of 10. Dr. Lisa Ginn, in an article entitled Understanding Helioplex, UVA, UVB, and SPF goes into detail on how to protect oneself from UVA and UVB rays.

While there is currently no FDA-approved rating system for gauging protection from UVA rays, most dermatologists strongly recommend everyday use, year round, of sunscreens labeled for “broad-spectrum” protection (ie, for UVA and UVB ) with an SPF of 15 to 30. Such products actually contain several sunscreen chemicals. For example, when avobenzone is combined with Helioplex as well as titanium dioxide or zinc oxide (agents that scatter sun rays) and oxybenzone (an excellent UVB blocker), the result is broad coverage over the entire light spectrum.

Look for next week’s post for more tips on how to protect your skin from the sun.

Published on 03/22/2010 | Last updated on 10/18/2018