Hey, I'm Flora Lichtenen, and this is Science Friday.

Today in the show, sunscreen.

What to look for and your burning sunscreen questions.

Ultimately, the key thing is this to recognize is that this ultraviolet radiation,

whether you're wearing sunscreen or not, is coming down on you.

So you need to protect yourself from it.

It's officially summer, and that means a few of my favorite things.

Barbecues, beaches, and broiling under the sun, which also means it's sunscreen season.

But if you meander down the sunscreen aisle in the drugstore, you're confronted with so many choices. Mineral, chemical, nano, non-nano, UVA,

UVB. What is the difference? What ingredients should you look out for? What belongs in the shopping

basket? And what doesn't? Here to shine

some light on some of those questions is Dr. Jonathan Unger, a dermatologist and medical director

of the Waldman Melanoma and Skin Cancer Center at Mount Sinai here in New York. Welcome to

Science Friday. Thank you for having me. Okay, so let's break down first sort of, you know,

it's been drilled into our heads. The sun can cause damage, but what is actually causing damage? And how much do we know about that?

So a tremendous amount of electromagnetic radiation travels from the sun down to our skin. There are many aspects of this sort of spectrum.

They include visible light, that's how we see, but among those is also ultraviolet light.

Ultraviolet light we can't see, but it is quite damaging to our cells and specifically the DNA of our cells.

We think of UV as three sort of sub-spectrums as UVA, UVB, and UVC.

UVC is actually by far the most damaging and is often used to sterilize because it basically

damages and kills all life.

Fortunately for us, our atmosphere really eliminates that.

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