Exposure to ultraviolet (UV) radiation is a major risk factor for most skin cancers. Sunlight is the main source of UV rays. People who are subject to large amounts of UV exposure are at a greater risk for skin cancer, even though UV rays make up only a very small portion of the sun’s rays. UV rays damage the DNA of skin cells and skin cancers start when this damage affects the DNA of genes that control skin cell growth. Knowing the difference between UVA and UVB rays is beneficial to learn about skin cancer prevention and can help you take precautions when you’re going to be in the sun.
What is the difference between UVA and UVB rays?
UV rays make up only a very small portion of the sun’s rays and they are the main cause of the sun’s damaging effects on the skin. There are three main types of UV rays: UVA, UVB, and UVC. Although UVC rays have more energy than other types of UV rays, they are not significant in relation to skin cancer as they are not contained in sunlight and they don’t penetrate our atmosphere. It is more important to understand the difference between UVA and UVB rays because they have a direct effect on our skin.
UVA rays are the sun’s ultraviolet A long-wave rays. Most of us are exposed to large amounts of UVA rays in our lifetime. They account for up to 95% of the UV radiation reaching the Earth’s surface. Although they are less intense than UVB, UVA rays are 30 to 50 times more prevalent. They are present with equal intensity during all daylight hours throughout the year and can penetrate the clouds and glass. UVA rays penetrate the skin more deeply than UVB and have been known to play a major part in skin aging and wrinkling.
Until recently, scientists believed it did not cause significant damage in areas of the skin where most skin cancers occur but studies over the past two decades now show that UVA damages skin cells called keratinocytes in the basal layer of the epidermis, where most skin cancers occur. UVA rays contribute to and may even initiate the development of skin cancers.
UVB rays are the sun’s ultraviolet B short-wave rays. They are the main cause of skin reddening and sunburn. They tend to damage the skin’s more superficial epidermal layers. They play a key role in the development of skin cancer and they contribute to tanning and wrinkling. Its intensity varies by season, location, and time of day, however, the most significant amount of UVB rays hit the United States between 10 am and 4 pm from April to October, particularly in the north-east.
However, UVB rays can burn and damage your skin year-round, especially at high altitudes and on reflective surfaces like snow or ice. Snow or ice will bounce back up to 80% of the rays; meaning that they hit your skin twice.
Skin Cancer Prevention Tips for UVA and UVB Rays
Protect yourself from UV radiation, both indoors and out. When outdoors, try to seek shade between 10 am and 4 pm. Since UVA penetrates glass, consider adding flat, tinted UV-protective film to your car’s side and rear windows as well as to house and business windows. This film blocks up to 99.9% of UV radiation and lets in up to 80% of visible light.
When outdoors, dress to limit UV exposure. Wear special sun-protective clothes with ultraviolet protection factor that indicates how much UV radiation can penetrate the fabric. Wear bright or dark-colored, lustrous clothes which will reflect more UV radiation than pastels and bleached cotton will. Tightly woven, loose-fitting clothes will also provide more of a barrier between your skin and the sun and broad-brimmed hats and UV-blocking sunglasses will help shield the sensitive skin on your head, neck, and around the eyes.
Since both UVA and UVB 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 a sunscreen with an SPF of 30 or higher. Look for sunscreens that have some combination of UVA-screening ingredients: stabilized avobenzone, ecamsule, oxybenzone, titanium dioxide, and zinc oxide. You might see the phrases multi spectrum, broad spectrum or UVA/UVB protection on sunscreen labels. Those all indicate that some UVA protection is provided.
Be Proactive about Skin Cancer Prevention
With UV radiation being the leading cause of skin cancer in the United States, safety precautions should not be taken lightly. At MoleSafe, our approach to skin cancer prevention is proactive and comprehensive. Our MoleSafe Skin Surveillance Program has the reliable accuracy to reveal skin cancer and melanoma at the earliest possible stage for fast, effective treatment. Contact us today to schedule an appointment.