Long hours of summer sunshine may improve our moods and provide ample opportunity for sunbathing, but what exactly does soaking in those rays do to our skin?
"What happens when the UV light hits our skin is the energy penetrates our skin and hits our DNA," dermatological surgeon Jerry Brewer of the Mayo Clinic said. "One of the most common things that happens after that is the formation of a pyrimidine dimer. That's when two different building blocks of DNA that are next to each other form a bond connecting them more tightly than they should be.
"So when our body is replicating that DNA, it's hard to figure out what that is. Instead of seeing two building blocks, it sometimes sees it as only one. And that causes a frame shift mutation."
Most of the time, Brewer said, the body is good about detecting those frame shifts, and it even has a repair system that uses the mirror image DNA strand to fix the broken one. But every once in a while, the repair system fails.
Still, there's a backup system in which cells commit suicide if it's changed too much. But when a cell slips by those two systems, "it sometimes gets changed in a very dramatic way that can lead to a lot of things, including cancer."