Attention, sunscreen skeptics: The sun’s UV rays are coming for you, and you’re just making their job easier. Summer is now upon us, which means more time in the sun — and more exposure to the ultraviolet radiation it emits. Longer-wavelength ultraviolet A rays can reach beneath the skin’s surface, causing it to age prematurely.
Shorter-wavelength ultraviolet B rays affect the outermost layers of skin, causing sunburns and tans. (A third type of rays, ultraviolet C, is intercepted by Earth’s protective ozone layer.) Both UVA and UVB damage the DNA in skin cells, causing mutations.
These mutations can accumulate over time and cause tumors to grow. The more UV exposure you have, the greater the risk, according to the Skin Cancer Foundation. Basal cell carcinoma is the most common type of skin cancer in the United States, followed by squamous cell carcinoma.
About 5.4 million of these cancers combined are diagnosed each year, and they cause between 2,000 and 8,000 deaths, the American Cancer Society says. Melanoma of the skin is both more rare and more deadly, affecting an estimated 100,640 Americans this year and resulting in 8,290 deaths, according to the National Cancer Institute.
Sunscreens can protect you from these malignancies in one of two ways. Chemical sunscreens contain ingredients such as avobenzone that absorb UV rays. Mineral sunscreens rely on zinc oxide or titanium dioxide to block or reflect the rays.
Either way, the solar radiation is unable to penetr.