Beach season is officially in full swing, with Americans heading to the coast to swim, lounge, camp, party and generally cool off from the heat-drenched cities. And because we’ve been so well trained to avoid the harmful ultraviolet rays that cause skin cancer, most beachgoers will be mindful to slather on a generous coating of sunscreen.
This is a sound and healthy practice for humans when they bake on the sands of California’s beaches, but it turns out it’s not so great for the health of the oceans when people covered in sunscreen take a cooling dip in the waves. A study conducted by an international team of scientists found that exposure to the two most common ingredients in sunscreen — oxybenzone, or BP-3, and octinoxate — is toxic to coral development in four ways. BP-3 in particular was correlated with bleaching, which is a sign of ill health, DNA damage and abnormal skeleton growth and deformities in baby corals (yes, there are baby corals).
In light of the estimated 14,000 tons of sunscreen entering the oceans literally on the backs of humans each year, Hawaii has taken the extraordinary step of banning the sale of sunscreen containing those two ingredients, starting in 2021. The prohibition would affect about 80% of sunscreens on store shelves.
Exposure to the two most common ingredients in sunscreen — oxybenzone, or BP-3, and octinoxate — is toxic to coral development.
This will no doubt be confusing to beachgoers who have been warned for years to take precautions against sunburn and are now being told that each squeeze of a tube of sunblock may be hurting the very ocean they’ve come to enjoy. But let’s be clear: This is no call to skip the SPF 50. Skin cancer is a serious and all too common affliction; one-fifth of Americans will be diagnosed with skin cancer by the time they are 70, according to the Skin Cancer Foundation.
Nevertheless, extreme action is called for in the struggle to maintain the health of the world’s coral reefs, which have been dying at alarming rates. Coral reefs aren’t just pretty — they are vital underwater ecosystems that support such a great diversity of species, some scientists compare them to rainforests. The 1,200 miles of Hawaii coral reefs have been ailing for more than a decade — a process that has sped up in recent years, most likely because of climate change.
The good news is that there are reasonable sun-blocking alternatives that aren’t linked to coral destruction and don’t require staying inside when the sun is out. Products that rely on minerals such as zinc oxide (think of the white film covering the noses of lifeguards and surfers) to reflect the harmful rays of the sun are still considered safe for the environment. And given the demand for sun protection, it’s reasonable to count on the personal products industry to develop new sunscreens that are not linked to coral destruction.
This is a good reminder that some of the measures we use to protect ourselves from one threat can boomerang into another problem. Another example is the liberal use of antibiotics that has resulted in the emergence of “superbugs” that are impervious to most of our life-saving antibiotics.
Sunscreens are just one of multiple threats to the health of the planet’s coral reefs. Warming oceans, pollution from industrial chemicals and trash are playing a larger role. For example, consider the estimated 8 million tons of plastic that migrate into the ocean each year. New research indicates that this cast-off plastic is not just choking whales and seabirds, it’s killing coral as well. For example, one study of 125,000 coral reefs in the Pacific and Asia reported that nearly 90% of those found with significant amounts of ocean-born plastic were diseased. Only 4% of the reefs free of plastic were sick.
Hawaii may be the only U.S. state to restrict some sunscreens, but its sunbathers are hardly the only ones introducing those pollutants into the environment. California surely contributes its share of sunscreen washed off from the bodies of all the swimmers, waders, divers and surfers enjoying its 1,100 miles of coast.
The threats to coral posed by climate change and pollution might be difficult if not impossible to mitigate. The threat from sunscreen is not — all it takes is for consumers to change brands. There’s no reason we can’t save our skin and baby corals at the same time.