The shocking downside of sunscreen


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Awareness of the impacts that some sunscreens can have on coral reefs has been on the rise in recent years. But while scientists knew that chemicals like oxybenzone were causing problems, they weren’t exactly sure why or how. Now, a group of environmental chemists and biologists has come up with an explanation.

The scientists first started their research because they wanted to know if the chemicals in “reef-safe” sunscreens were actually safer for corals compared to oxybenzone. According to the National Oceanic and Atmospheric Administration (NOAA), sunscreens can wash off human skin as we swim or shower, then the sunscreen may accumulate on corals. There, the chemicals can trigger bleaching events or damage DNA.


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But why do these chemicals protect human skin but harm coral reefs and other marine life? The new research found that corals absorb oxybenzone and then convert it into phototoxins. These molecules become harmful when exposed to sunlight.

The study started with sea anemones, which can act as a model for coral reefs, two of the study authors, Djordje Vuckovic and Bill Mitch, shared in The Scientist. Coral is difficult to work with in a lab, but sea anemones are similar, even down to their relationships with algae living in them. 

The researchers placed 21 sea anemones in test tubes of seawater. Above, they set up lights that mimic sunlight’s full spectrum. Five test tubes were covered with acrylic to absorb the same UV wavelengths that oxybenzone does. The sea anemones were exposed to 2 milligrams of oxybenzone per liter of seawater; just 0.14 milligrams per liter is enough to kill coral larvae, yet as much as 1.4 milligrams have been found in reefs near popular tourist destinations, such as the U.S. Virgin Islands.

On day six of the experiment, the first sea anemone in the “light” group, which was not protected by the acrylic box, died. By the seventeenth day, every sea anemone in this group had died. The experiment ran for 21 days, and by the end, all of the sea anemones in the “dark” group covered by the acrylic box were still alive.

The researchers tested the sea anemones in the light group and found that their cells had replaced a part of the oxybenzone chemical structure, an alcohol, with a sugar. This prevented the oxybenzone from protecting against UV light, instead causing it to damage cells when exposed to sunlight.

The authors explained that the research draws attention to a few issues: one being that this process could happen with other organisms, including humans. Coral bleaching events, which can be caused by climate change and warming oceans, make the corals more susceptible to sunscreen accumulation and its damaging effects. And their final concern? “Reef-safe” sunscreens may not be all that great, either.

“The chemicals used in many alternative ‘reef-safe’ sunscreens contain the same alcohol group as oxybenzone so could potentially also be converted to phototoxins,” Vuckovic and Mitch wrote.

This article originally appeared on and was syndicated by

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10 of the prettiest beaches in the US

10 of the prettiest beaches in the US

Wish you could laze on a beach under clear blue skies, soaking up some sunshine with crashing waves setting the soundtrack? It’s time to stop daydreaming and “seas” the day /by finally planning that beach getaway.

Driftwood Beach’s dramatic landscape of fallen trees and scattered driftwood make it look otherworldly. Its “tree graveyard” is appealing to photographers looking to capture the unique beauty of nature. You’ll want to have your digital camera or at least your phone camera handy at all times on this beach (and check out our lists of the best digital cameras and best GoPro cameras while you’re at it).

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Fort Lauderdale Beach is all grown up now. Once a rowdy spring break mecca popularized in movies, the Florida beach has evolved into a tony destination, with luxurious hotels and beach clubs.

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St. Augustine, which is America’s oldest city, boasts 42 miles of white sand beaches. If you can peel yourself from your sunny patch of sand, there are Spanish forts and centuries-old buildings to explore, too.

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Keep your eyes peeled. You just might spot some migrating whales from Hapuna Beach State Recreation Area, a sun-soaked white sand oasis that stretches for a half of a mile. Visitors can also rent snorkeling gear and boogie boards on the beach.

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Sunsets are so stunning at Siesta Key that they get a weekly Sunday night celebration, complete with a drum circle and belly dancers putting on performances. The family-friendly beach features shallow waters and a playground.

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If you like a splash of adventure with your beach vacation, Pensacola Beach can fill up your itinerary with scuba diving, sports fishing, jet skiing and parasailing. Or, simply enjoy the sugary white sand beaches. The Pensacola Pier is the perfect perch for spotting dolphins.

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St. Pete, located on Florida’s Gulf Coast, is nicknamed the Sunshine City and holds the title of most consecutive days of sunshine with 768 days of straight sun. Impressive, right? If you happen to need a break from all that light, though, set aside an afternoon to explore the Salvador Dali Museum.

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Do you like long walks on the beach? Panama City Beach has 27 miles of white sand beaches for the perfect stroll. Round out your visit by taking a spin on the SkyWheel, which soars as high as an 18-story building and shows off panoramic views of this Florida beach town.

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Don’t miss the daily cliff diving ceremony that plays out on Maui’s Ka’anapali Beach. The time-honored tradition happens at sunset on Puu Kekaa, the beach’s northernmost cliffs.

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Crystal waters, soft white sand and family-friendly amenities help Clearwater Beach nab the top beach award for the second year in a row. After a day on the beach, enjoy nightly sunset celebrations at Pier 60, where street performers put on shows and local vendors sell crafts. TripAdvisor reviewers also rank neighboring St. Pete Beach highly, so you could easily enjoy two of the nation’s best beaches during a single vacation.

So, did your favorite beach make the Top 10 list? If not, which beach do you think should have made it?

You can see TripAdvisor’s expanded Top 25 list here.

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