Ultraviolet rays are part of the electromagnetic spectrum found in sunlight. These rays are invisible to the naked eye and are classified according to their wavelengths as UVA, UVB, or UVC. The majority of UVC radiation is absorbed by the ozone layer and never reaches earth. UVA and UVB rays, on the other hand, are able to penetrate the atmosphere. Both of these rays can cause mutations in the skin’s cellular DNA that can cause various skin malignancies as well as eye damage and premature skin aging. Protect against skin cancer with early prevention and detection.
UVA Rays
UVA radiation is what causes the skin to tan. Tanning is actually a skin injury that occurs when the skin produces extra melanin as a way of protecting itself from the DNA damage caused by ultraviolet radiation. UVA radiation has long been associated with wrinkling and premature skin aging. Since UVA rays penetrate deeper into the skin than UVB rays, most scientists did not believe until recently that it contributed to skin cancer. Studies conducted over the past 20 years, however, have shown that UVA rays damage skin cells known as keratinocytes where basal cell and squamous cell skin cancers often develop. There is a common misconception that tanning beds are a safer alternative than natural sunlight. In fact, tanning booths rely primarily on UVA radiation that is approximately 12 times that of the sun.
UVB Rays
UVB radiation primarily affects the outer layer of the skin and is the leading cause of sunburns. These rays also play a significant role in skin damage and the development of skin cancer. Although UVB rays are present year-round, they are strongest between 10 a.m. and 4 p.m. from April through October. The rays are also stronger at high altitudes and around reflective surfaces, including water, snow, and ice.
Protecting Skin Against UVA and UVB Rays
It is best to seek shade or avoid spending extensive time outdoors during the middle of the day when ultraviolet rays are the strongest. When going outdoors, always wear a sunscreen with a sun protection factor of 15 or better and wear clothing that blocks sunlight from hitting the skin. Broad-brimmed hats and sunglasses can help protect the face and eyes. Tinted ultraviolet-protective films can help block UVA rays from entering through windows in cars and buildings. Even with protective measures, skin cancer can still occur. Spot potential skin malignancies early by performing monthly skin self-exams and to see a dermatologist annually for a full-body skin check-up.