Preventing Risk of Skin Cancer Skin cancer is the most common form of cancer, affecting more than half a million people each year. 90% of skin cancers are linked to over-exposure to the sun, and even one sunburn may increase your risk of contracting skin cancer later in life. Fortunately, skin cancer is also one of the easiest cancers to prevent. Being “sun smart” is the first step in reducing your risks, and understanding that year-round protection from sun exposure is important. Ultraviolet (UV) rays are wavelengths in the spectrum of light from the sun. They can reach you on cloudy and hazy days, as well as bright and sunny days. They are out during fall and winter as well as during the spring and summer. UV rays also reflect off of smooth surfaces like water, cement, sand, and snow, which can actually increase the power of chance of sunburn. UVA and UVB Rays UVA are the long-wave rays of the sun that remain the same strength year-round. These rays penetrate the top layer of skin and can damage the dermis, or second skin layer. Prolonged exposure to UVA shrinks and damages the collagen and elastin in the skin. This results in the top layer of skin start to droop or wrinkle. Additionally, UVA ray exposure may dilate blood vessels (causing a red flush), cause freckles or larger brown or white spots on the skin. UVA damages skin cells called keratinocytes in the basal layer of the epidermis, where most skin cancers occur, and may start and contribute to the development of skin cancers. UVA rays are the type used in tanning beds; using these actually accelerates the skin’s aging process. UVB are the short-wave rays that change with the seasons and time of day, and are most intense from April to October. However, UVB rays can burn and damage your skin year-round, especially at high altitudes and on reflective surfaces such as snow, water or ice. Unlike UVA, UVB only penetrates the top layer of skin, but are the key cause of sunburn and are also linked the development of skin cancers. How Does Sunscreen Work? Since both UVA and UVB rays are harmful, you need protection from both kinds of rays. To make sure you're getting effective UVA as well as UVB coverage, look for phrases such as broad spectrum or UVA/UVB protection on sunscreen labels. The FDA has identified sunscreen ingredients that safely offer broad-spectrum (UVA and UVB) protection. These include Benzophenones (often identified as oxybenzone), Cinnamates (often identified as octinoxate or cinoxate), Ecamsule (often marketed as Mexoryl or Mexoryl SX), Sulisobenzone, Salicylates, Zinc oxide, and Titanium dioxide. Check the label of products to see if these ingredients are included. Sun protection products have a number associated with its ability to protect you from the sun, or called “sun protective factor” (e.g., SPF). The SPF number on a sunscreen © 2021, Katz, L. adapted from Women’s Self Care, Inner Wisdom Press, 1 label is usually between 2 and 50. SPF numbers are supposed to tell you how long a sunscreen protects your skin from burning. But in reality it is not that exact because there are many factors that contribute to its effectiveness. (This is a common misconception about SPF.) SPF 30 sunscreen absorbs roughly 97% of UVB rays, but factors such as perspiration and activity level, location, time of day and year, can change that percentage. If you are exposed to the sun it should be applied every two hours or so, more frequently if you have gone into water or perspired. Getting into the habit of applying sunscreen every day you are exposed to the sun—even on cloudy days—can help protect your skin and prevent premature aging and reduce risk of skin cancers for years to come. To protect your skin from the sun, use sunscreen with sun protective factor (SPF) 15 or higher that offers both UVA and UVB protection. In general, SPF 30 is regarded as a good, all-purpose sunscreen for active people who spend extended time outdoors. Dermatologists often recommend a SPF of no less than 15. Additionally, wear polarized sunglasses that offer full-spectrum protection to block both UVA and UVB rays, and wear lightweight clothing and a hat with a brim to protect exposed skin, on the face, head, ears, and neck. If you use make-up, choose those that contain SPF, so that it becomes part of your daily routine. During the hours between 10:00 a.m. and 4:00 p.m., when the sun’s rays are the strongest, seek shade. © 2021, Katz, L. adapted from Women’s Self Care, Inner Wisdom Press, 2 .