This is scientific American 60 second science.

I'm Christopher Intagiyata.

Last time you hit the beach, and I know it probably seems like a distant memory

in the currently chilly parts of the world. Did you pack sunscreen? A beach? a First contender a beach umbrella which they evaluated with a spectrophotometer to see a

UV rays pass through. They didn't. Good sign so far. The second contender was sunscreen,

a hundred SPF. Then the scientists rallied 81 people to go sunbathing at a lake outside Dallas for three hours around midday. Half got beach umbrellas, the other half all you can apply sunscreen.

And because this is science, not a day at the beach, or not a walk in the park,

the participants were not allowed to take a dip.

24 hours after the solar exposure, enough time for any sunburns to ripen,

the researchers visually inspected the sun seeker's skin,

and they found that three times as many umbrella sitters had sunburns somewhere on their bodies

compared to their sunscreen slathering neighbors.

And since the umbrellas themselves block UV rays,

the burns are likely due to UV light bouncing off the

sand and other surfaces then hitting unprotected skin. The study is in

Jama dermatology. The caveat here, even sunscreen users were not completely burned free.

So the researchers, some of whom full disclosure work at Johnson and Johnson, which makes sunscreen,

instead recommend hedging your bets.

Wear a wide-brimmed hat, sit in the shade, use sunblock too,

to ensure you don't need that fourth strategy, Aloe vera.

Thanks. strategy, Aloe vera. Thanks for listening.

For Scientific American 60 Second Science, I'm Christopher N' D'Eljata.

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