Research: Sunscreen - danger to corals

An international study with the participation of researchers from Tel Aviv and Ben Gurion Universities revealed that the sunscreen that protects us from the sun's radiation causes enormous and irreversible damage to coral reefs all over the world. The study is published in the journal Archives of Contamination and Toxicology

Every small child knows that when exposed to the sun, they must apply sunscreen, which filters out the harmful UV rays. However, a new international study, with the participation of researchers from Tel Aviv University, suggests that a common radiation blocking substance, which is a key ingredient in most types of sunscreen, is extremely toxic to the environment in general and corals in particular. The current study is a continuation of a previous study from January 2014, which provoked many and upset reactions all over the world.

The new research was carried out by Dr. Omri Bronstein and Prof. Yossi Levia from the Department of Zoology at Tel Aviv University, in collaboration with Dr. Craig Downs from the Haereticus Environmental Laboratory in Virginia, and with other colleagues in the USA and Ben Gurion University. The study was published this week (October 20.10) in the journal Archives of Contamination and Toxicology.

Disruptions in hormonal mechanisms

"We are engaged in a field known as eco-toxicology - a science that focuses on substances that are harmful to the natural environment, and their effect on flora and fauna," explains Dr. Bronstein. "With the expansion of research activity, more and more damage is being discovered caused by seemingly 'innocent' products, especially food and cosmetics. In this study, we chose to focus on a radiation-blocking substance called oxybenzone, which is a key ingredient in almost every standard sunscreen, and tested its effect on coral reefs in the sea."

The first phase of the research was carried out in the laboratories of the Interuniversity Center for Marine Sciences in Eilat. Exposure of coral 'preemies' to oxybenzone in various concentrations, brought up extremely alarming findings even at a minimal concentration of 62 parts per trillion (0.062 micrograms per liter): damage to the DNA in the embryonic stage, severe structural deformations and hormonal disorders, which disrupt the skeleton building mechanisms, and cause the young corals to be buried in the skeleton they themselves produce. At the same time, tissues of mature corals were also examined, and disruptions in hormonal mechanisms and DNA were also observed in them.

In addition, the experiment examined the effect of oxybenzone on the corals under conditions of light and darkness, and found that its toxicity increases significantly when exposed to light. When it comes to coral reefs, which are found in sunny geographic areas in the first place - where humans also use a large amount of sunscreen, a particularly deadly cycle is created.

Deadly concentrations on bathing beaches

In addition to laboratory tests, the researchers conducted environmental monitoring of beaches in two geographic areas: Hawaii in the Pacific Ocean and the US Virgin Islands, located in the Caribbean Sea. In both places, the oxybenzone concentrations were measured at popular bathing beaches, which attract many bathers who use sunscreen, in front of sites that are relatively far from the bathing beaches. Areas where sewage from nearby cities are discharged into the sea were also examined. The concentrations of the toxic substance found in the water were enormous: up to 800 parts per trillion in Hawaii, and up to 1.4 parts per million in the Virgin Islands - 13 times and 23 times respectively the concentration diagnosed as harmful in the laboratory.

"Our research has proven that oxybenzone, which is found in almost every sunscreen, causes tremendous damage to coral reefs, and especially to coral juveniles," states Dr. Bronstein.
"Coral embryos damaged by oxybenzone are no longer able to settle in the reefs and maintain their animal succession. This means that many reefs all over the world, which were damaged in the past by a wide variety of factors - whether man-made or extensive global changes, will not be able to recover and rehabilitate." According to him, this fact also has an economic significance: many funds are invested today in the restoration of coral reefs, but in light of the research findings it is quite possible that this is a waste of public funds; This is because there is a high probability that the reefs, especially those located near bathing beaches or estuaries, are not at all amenable to restoration. The conclusion: under the existing conditions, it may be more correct to allocate resources to reduce the damages - which continue to accumulate at an alarming rate - instead of trying to correct their consequences.

"Following our previous study, which examined another radiation blocking substance (benzophenone 2), the use of sunscreen has already been banned in several places in the world," says Dr. Bronstein. "The authorities - such as the US National Park Service - are launching massive campaigns to encourage protection through passive and available means such as long clothing and wide-brimmed hats, and to increase awareness of the use of protective materials that do not contain the harmful chemicals. At the same time, many countries, including the USA, Japan, the European Union and even Israel, are working to change the legislation and update the procedures for labeling and granting licenses for products containing the toxic substances."

The current study further strengthens the awareness of the seriousness of the problem. "Our new findings highlight the dangers hidden in a large part of the products that we consider to be health and protective preparations. Moreover, the study sends a clear message to the cosmetics companies, that they must act immediately to improve their products. Because, beyond the serious damage to the environment, we are also advised to think twice before applying a toxic substance to our bodies, which causes fatal mutations and serious damage to DNA and the hormonal system."