Oxybenzone causes coral bleaching, say researchers from Ben-Gurion University of the Negev
On May 4, the Hawaii state legislature passed a ban on sunscreen ingredient oxybenzone (BP3) after a team of researchers from Israel and the United States provided significant evidence that BP3 has caused coral bleaching at sites in Hawaii as well as in Eilat and the Caribbean.
Under the new legislation, which takes effect in 2021 once signed by Governor Dave Ige, sunscreens containing this chemical will be banned since only a drop of the substance can contribute to coral bleaching.
The European Union attempted a similar ban and may now gain traction since the Hawaii bill passed. BP-3 is used in more than 3,500 personal-care products sold around the world to protect against the damaging effects of ultraviolet light.
The Israeli-American findings, originally published in October 2015 in the Archives of Environmental Contamination and Toxicology and reported by ISRAEL21c, indicate that oxybenzone coming from swimmers’ skin, municipal sewage discharge and coastal septic systems pollutes coral reefs.
“We found that oxybenzone caused gross morphological deformities, DNA damage and endocrine disruption, which causes the coral to close up and die,” explained Prof. Ariel Kushmaro of the Environmental Biotechnology Lab in Ben-Gurion University of the Negev’s Avram and Stella Goldstein-Goren Department of Biotechnology Engineering.
“We are pleased to see our research will have a measurable impact on saving shrinking coral reef communities under siege from chemicals, waste runoff and climate change,” Kushmaro added.
As much as 14,000 tons of sunscreen lotion are emitted into coral reef areas annually, much of which contains between one and 10 percent oxybenzone. The authors estimate that this year at least 10 percent of global reefs are at risk of high exposure, based on reef distribution in coastal tourist areas.
Corals in danger
According to the study, oxybenzone was observed in seawater within coral reefs in Hawaii and the US Virgin Islands in concentrations as low as 62 parts per trillion, the equivalent of a drop of water in six-and-a-half Olympic-sized swimming pools, and as high as 800 parts per trillion to 1.4 parts per million – more than 12 times higher than the concentrations necessary to adversely impact coral.
The study found that oxybenzone is a photo-toxicant with adverse impacts exacerbated in light. But even in darkness, planulae (larval coral) were transformed from a mobile state to a deformed, immobile condition and exhibited an increasing rate of coral bleaching in response to increasing oxybenzone concentrations.
The scientists say this is particularly relevant for areas facing mass bleaching events, including Hawaii and the Israeli Red Sea resort of Eilat.
“In Israel, there is widespread use of sunscreens utilizing chemicals from the benzophenone group,” said Kushmaro.
“According to measurements not included in the study, similar concentrations of benzophenone have been found near the coral reefs in Eilat. Since it is likely that these chemicals are being washed off of swimmers’ bodies, it stands to reason that concentrations would be higher in swimming and snorkeling areas, such as the coral reef reserve in Eilat.”
In addition to Kushmaro, the Israelis involved in the study of BP3’s effect on corals included Esti Kramarsky-Winter, Yona Lichtenfeld and Rina Jeger of BGU; Prof. Yossi Loya, Roee Segal and Omri Bronstein from Tel Aviv University’s Department of Zoology.
American marine scientists from the University of Hawaii, National Aquarium, US National Oceanic & Atmospheric Administration, Haereticus Environmental Laboratory and University of Central Florida also participated in the study.
By: Abigail Klein Leichman