More research highlights threat to coral reefs from sunscreen chemical

A new study by scientists from Tel Aviv University provides further proof that sunscreens can be toxic to the delicate eco system that sustains coral reef.

The research, which is published in the Archives of Environmental Contamination and Toxicology, specifically finds that although sunscreens with an SPF higher than 15 are playing a very important role in preventing skin cancers, they are also “very bad for the environment”.

The Israeli research show that a chemical that is commonly formulated in sunscreens – oxybenzone (benzophene 3) - poses what the scientist term as an ‘existential threat’, even if the dosing is in tiny amounts.

Oxybenzone is the go to for sunscreens

"The chemical is found in more than 3,500 sunscreen products worldwide. It pollutes coral reefs via swimmers who wear sunscreen or wastewater discharges from municipal sewage outfalls and coastal septic systems," said Dr. Omri Bronstein of TAU's Department of Zoology, one of the principal researchers.

The research was conducted in conjunction with the Inter University Institute in Eilat, through a series of experiments that used coral embryos.

The study hypothesizes that the average person spending a day at the beach and taking intermittent dips in the sea might reapply sunscreen two to three times, as instructed on most sunscreen labels to ensure adequate protection from the sun.

This equates to two to four ounces of sunscreen per person, which when multiplied by every other person who might also be spending the day at the beach and using sunscreen, equates to a serious risk to marine and coral life.

Pollution is far reaching

"Oxybenzone pollution predominantly occurs in swimming areas, but it also occurs on reefs 5-20 miles from the coastline as a result of submarine freshwater seeps that can be contaminated with sewage," said Dr. Bronstein.

"The chemical is highly toxic to juvenile corals. We found four major forms of toxicity associated with exposure of baby corals to this chemical."

Previous studies have already pointed to various forms of toxicity to coral reefs after exposure to sunscreens and  specifically oxybenzone, including coral bleaching as well endocrine disruption.

Bleaching and endocrine disruption

The Israeli scientists noted that the bleaching effect was enhanced by higher sea-surface temperatures, resulting from weather events like El Niño, while oxybenzone was also found to damage the DNA of the corals.

Likewise, the endocrine disruption resulted in young coral becoming encased in its own ‘skeleton’, ultimately causing it to die or become grossly deformed.

The tiniest amount of the chemical oxybenzone also led to significant damage to coral reefs, with the scientists noting that a toxicity effect could be detected from as little as 62 parts per trillion.

"Current concentrations of oxybenzone in these coral reef areas pose a significant ecological threat," said Dr. Bronstein.

"Although the use of sunscreen is recognized as important for protection from the harmful effects of sunlight, there are alternatives -- including other chemical sunscreens, as well as wearing sun clothing on the beach and in the water."

Marine-friendly sunscreens

On the back of an increasing body of evidence concerning the damage sunscreens may do to coral reef, there have been a number of marine-friendly alternative products that have been launched on the market in recent years, mainly based on natural ingredients.

Indeed, back in August a team of global scientists claimed they had come up with a natural-based sunscreen that was inspired by the strategy fish, algae and microorganisms develop as a means of UV protection.

The inspiration for the research came from the fact that an increasing body of evidence is pointing to the environmental impact of sunscreens.

The team of scientists from Sweden, Spain and Australia have developed a novel UV-protective materials exclusively consisting of natural compounds that are more easily biodegradable.