Ultraviolet (UV) light is the primary culprit in the development of skin cancer. But how does it cause skin cancer? Is all UV radiation the same? Can you protect yourself from UV light? Learn the basics of UV radiation so you have another tool in your belt in the fight against skin cancer.
UV light is a natural energy put out by the sun. Radiation is the output of energy from any source, from high energy to low. UV light is in the middle of the continuum while X Rays use high energy radiation and radio wavelengths are low energy radiation. UV radiation has shorter wavelengths than visible light, so it can’t be seen by the eye. But your skin can feel it. There are human-made sources of UV light, such as tanning beds, sun lamps, welding torches and devices used in phototherapy. UV light is broken into 3 types: UVA, UVB and UVC. 95% of the sun’s rays that reach the ground are UVA rays. UVA rays are the lowest energy radiation and are mostly responsible for the aging of the skin. UVB rays have a shorter wavelength than UVA rays and are higher energy. They cause sunburns and are the most responsible for causing skin cancer. The sun also emits UVC rays, the highest energy of the UV rays. But UVC rays react with the ozone high above the earth and don’t reach the ground.
When UV light hits the skin repeatedly, your skin reacts by increasing the production of melanin, the dark pigment in the outer layer of your skin (the epidermis). This defense mechanism in your skin is what causes a tan. A tan is actually your body trying to block the UV rays from doing further damage to your skin. But when you can’t produce enough melanin because of having fair skin or because of too much prolonged exposure to the sun, your skin burns, and in severe cases, blisters. Sun damage isn’t only signaled by tans and sunburns. UV radiation (both UVA and UVB rays) can cause cumulative damage. This damage results in mutating the genes in skin cells. The mutated genes cause skin cells to start replicating abnormally, which then causes the growth of tumors on the skin. These growths are what we call skin cancer. The two most common types of skin cancer, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) usually develop in areas of the body that get a lot of sun exposure. Melanoma, the most deadly of the skin cancers, has also been linked to UV radiation, both from the sun and from tanning beds.
All UV light is not the same. UV light can vary in intensity, based on a number of factors. The more intense the radiation, the more damaging it can be. The time of day affects UV radiation, too: sunlight is most intense from around 10am-3pm. Your geographic location also determines the strength of the UV rays. The closer you are to the equator and the higher in altitude you are, the stronger the rays. UV rays are also going to be more intense in the spring and summer. Your surroundings can affect the strength of UV rays that your skin is exposed to. When you are exposed to sunlight both directly from the sun and reflected from surfaces, you are getting at least double the amount of radiation. Surfaces that can reflect a high amount of UV rays include water, sand, snow and glass. The UV light from tanning bed lamps also varies -- some is more intense than others, depending on the type of bulbs used.
There are some important measures you can take to block UV radiation from your skin and eyes. Clothing is one of the best ways you can shield your skin. Dense and thick fabric is recommended, as a tight weave will not allow much light to penetrate the fabric. Dark or brightly colored clothing does a better job of protecting your skin because it absorbs the rays instead of allowing them to go through the fabric. Loose-fitting clothing is more effective at blocking UV rays -- tight-fitting clothing stretches the fabric and allows more exposure to UV radiation. Using sunglasses when outside is also recommended for blocking UV rays from damaging your eyes. Skin cancer can grow on your eyelid, and UV rays can lead to eye issues like cataracts and macular degeneration. Sunscreen is another key weapon of skin cancer prevention. Choose a broad-spectrum sunscreen that will protect your skin from UVA and UVB rays. It is recommended that you daily use a sunscreen with an SPF of at least 15 and use one with SPF 30 or higher on days you are in the sun for longer periods of time. And remember UVA radiation penetrates clouds and glass. So, protect your skin on cloudy and sunny days and when in the car. Windshields typically filter UV light, but side windows do not.
Call Vanguard Dermatology, located in the greater New York City area. The board-certified dermatologists at Vanguard are trained to detect, treat and work to prevent skin cancer. Make an appointment today to schedule your skin cancer screening or to receive skin cancer treatment.