In October 2015 a group of scientists from the U.S. and Israel published a paper in the journal, Archives of Environmental Contamination and Toxicology entitled: Toxicopathological effects of the sunscreen UV filter, Oxybenzone (Benophenone – 3), on coral planulae and cultured primary cells and its environmental contamination in Hawaii and the U.S. Virgin Islands. Not exactly a catchy title is it? Yet this scientific paper with its exact and very dull title has sparked global headlines that put the blame for the destruction of the world's coral reefs firmly at the door of sunscreens and by implication the swimmers, snorkellers, divers and tourists who use it.
We were going to show you the full abstract from the paper but it is long, full of hard words and we really didn't have the time or inclination. So here's a quick summary. Certain sunscreens contain the active ingredient Oxybenzone which, the paper points out, has been found to have a destructive effect on coral DNA leading to coral bleaching and the ossification of coral planulae – juvenile coral literally become encased in their own skeleton and die.
This isn't the first time that such a link has been made between coral destruction and sunscreens either. Back in 2008, another group of scientists, this time from Italy, published a paper in the journal of Environmental Health Perspectives entitled: Sunscreens cause coral bleaching by promoting viral infections. Now, you have to admit, there is no ambiguity in that title. No wishy-washy use of the term “effects”. The Italians were adamant, sunscreens cause coral bleaching. The Italian experiments showed that sunscreens cause rapid and complete bleaching of hard coral. The effects of sunscreens is due to organic ultraviolet filters, which are able to induce the lytic viral cycle in symbiotic Zooxanthellae with latent infections. Nope, we don't now what that means either but the Italians concluded it wasn't very good. And that with increasing tourism to some of the worlds most precious marine environments and the associated use of sunscreen in those environments, things were going to get worse. However they did not single out Oxybenzone in particular, rather they found sunscreens containing parabens, cinnamates and camphor derivatives as well as Oxybenzone contributed to coral bleaching even at low concentrations.
Things then, don't look good for the manufacturers of sunscreens or the doctors who demand that we smear the stuff all over ourselves even on cloudy days (see, Tell Doctor Doom To Get A Life). Nor do things look that rosy for all the global warming fanatics either. After all if it's sunscreen smothered tourists that are destroying the reefs and not global warming – sorry climate change- then a lot of scientists are going to end up stacking shelves down the local supermarket. Another conspiracy perhaps?
But before you you go out and buy some non-chemical, dolphin friendly, coral reef loving sun lotion made from papaya juice and hippy spit from your local organic shop, let's sit back and think about this for a minute. These are scientific papers and as such they conform to the scientific notion of “put up or shut up”. In other words, these scientists have done their experiments, examined the results, hypothesised, formed their conclusions and published their work to all and sundry. Then they have sat back and waited for their results to be examined and either confirmed or criticised. Granted the Italians could be accused of having been a bit unwise by being so adamant - which in scientific terms is a little like walking around a fireworks factory with a naked flame, sooner or later something will blow up in your face – but nevertheless they have published and waited for the response, not from journalists who are just after a good headline, but academics. And the response has been... Well.... not all that great really.
A number of scientists and experts have cast doubt on the studies. Responding to the 2015 study, Terry Hughes, Director of the Australian Research Council of Excellence for Coral Reef Studies at James Cook University (wow what a title) thought the paper's findings were inconclusive.
“This particular study was done in a laboratory, so they actually used artificial sea water,” Hughes explained. “They put tiny bits of coral into aquaria and then added some chemicals. It's not surprising that corals don't like chemicals thrown at them.”
Hughes went on to say that the media's extrapolations that sunscreen is threatening the worlds coral “are a bit of a stretch”. “The conclusion from the media is sunscreen is killing the worlds coral, and that's laughable. The biggest stresses are climate change, overfishing and pollution, and pollution more generally than sunscreen.”
Hughes explained further that: “Sunscreen, because of its source is far less of a problem than run-off of pesticides from rivers.” The study claims that at least 10% of global reefs are at risk of exposure. “Many reefs are remote, without tourists and many of them are nonetheless showing impact from climate change... If you want to study global threats you have look on a global scale and they haven't done this.” Hughes said.
Mike Van Keulen, Director of Coral Bay Research Station at Murdoch University thought that laboratory studies were going to be limited in their scope but that the 2015 study did provide some concerning information about the toxicity of compounds contained in sunscreen. “If we start adding all these little things, sunscreen but also sewage, overfishing... They will altogether reduce the resilience of coral reefs.”
Craig Downs, one of the lead authors of the 2015 study said: “Whatever island/reef system that is populated and sees intense visitation (by tourists) you have sunscreen usage and hence contamination.” Downs however, agreed that it is not just swimmers that are the problem but also sewage. “My professional opinion,” Downs said, “is that agricultural run-off and sewage... are probably responsible for the historical collapse of coral reefs for the past 40 years.” Err... Okay, so why study sunscreens then?
Writing on the Dermal Institute website Dr Diana Howard offered up some rather cutting criticism of the 2008 study. Citing the lead author of the Italian study Dr Howard wrote: Dr. Robert Danovaro at the Polytechnic University of the Marche in Anacona, Italy (Environmental Health Perspective vol 116, April 2008) published a study that stated, "4-6,000 metric tons of sunscreen wash off swimmers per year globally." He calculated that "10% of coral reefs are in danger" and stated "chemical sunscreens should be avoided in favor (sic) of physical sunscreens." He did however note that, "sunscreens are not the only factor behind declining reefs". As you might expect the media chose to overlook this latter point and instead scare the public into not wearing sunscreens. Likewise, some clever marketers decided to brand coral reef safe sunscreens which use zinc oxide and titanium dioxide instead of chemical sunscreens. Of course it would only be a matter of time before someone complained that these physical sunscreens were not biodegradable and also detrimental for the earth.
Dr Howard then when on to cite a plethora of other experts who took umbrage with the study including the aforementioned Terry Hughes, he of the very impressive title. “Any contaminant can experimentally damage a coral under artificially high concentrations. The amount [in the wild] must be tiny due to dilution," Hughes said. "Imagine how much water a tourist wearing one teaspoon of sunscreen swims through in an hour-long snorkel. Compared to real threats like global warming, run-off and overfishing, any impact of sunscreen is unproven and undoubtedly trivial.”
Prof. Hoegh-Goldberg, Biological & Chemical Sciences at University Queensland stated: "This study is stretching the findings and conclusions to ridiculous extremes." In addition, Durwood Dugger, University of Florida, and founder of Biocepts Aquaculture commented that, "the authors conclusions are neither valid nor supported scientifically; you must consider the dilution factor in the ocean. There is no sampling of ocean waters around reefs to determine if sunscreens are even present and no one has ever detected sunscreens in the ocean. Furthermore, they have not excluded other environmental contributing factors. It is an accepted fact that during the past 20 years, coral bleaching has increased dramatically. Some possible causes include temperature change, excess UV radiation, pollution, bacterial pathogens, pesticides, hydrocarbons, other contaminants."
Professor Hoegh-Goldberg went on to point out that the study is interesting, but notes that many factors are likely to be responsible. "Bleaching is like a runny nose: there are lots of things that could cause it. Climate related bleaching is a direct consequence of heat stress and does not involve viruses or bacteria."
Dr Howard concluded her piece by writing: As you can see the claim that sunscreens are destroying our coral reefs is not well supported by many authorities in the scientific world and it would be premature and quite frankly dangerous for individuals to STOP wearing sunscreen while at the beach or swimming until such time that this claim can be fully supported with scientific facts. Unfortunately, many journals and papers have reignited interest in this story as we enter into summer season and we are already getting questions from consumers about the safety of sunscreens and the coral reefs. It is my expert opinion, as well as that of many other scientists around the world, that until additional studies are done to confirm or substantiate the 2008 study there should be no concern that sunscreens are harming the environment. So go to the beach, have a great time and wear your sunscreen!
So as far as we can see the jury is out on the subject, not that you'd notice from all the media coverage that seems more adamant than the Italians. A quick scan of the web and you'll be confronted with news stories and opinions that all use dramatic and unambiguous language. Sunscreens “are” destroying coral reefs. Sunscreens “damage” coral reefs or that we are all (meaning tourists) “directly contributing” to coral reef destruction. Yet the evidence doesn't actually support these unequivocal headlines.Then there are the “safe-sunscreen” manufacturers who've spotted a an opportunity and, luckily, have a ready supply of coral safe sunscreens ready to deliver to you door in exchange for a hand full of bucks. And there are the environmental bloggers/activists demanding the banning of everything from Oxybenzone to tourism, even the diving organisation PADI has a web-page offering advice on “safe sunscreens” for divers. Most of you will know that we don't think much of PADI in the first place and the fact that they offer advice on sunscreen doesn't help them in our minds, in fact they've gone down even further in our estimations. The fact is that we have read the studies and although we are not scientists, we can still find some glaring flaws. For one thing there are only two studies in total on the subject. Yep that's right only two. We'll say that again, just to be adamant about it, There are only two studies! And neither actually agree on the effect of sunscreens on coral. The Italians believe that sunscreens effect coral by promoting viral infections.
The 2015 study, on the other hand says it is down to sunscreens causing DNA damage. So that's two research papers using similar methodologies that have come up with two very different conclusions and both have come in for some heavy criticism in regard to their methodology, extrapolation of results, failure to take into consideration other environmental factors and their conclusions. In short, they've put up and been told to shut up.
You could always argue that those who pour scorn on the research would say that wouldn't they? After all, as we pointed out earlier, they don't want to end up packing bags in a supermarket when their own research gets lampooned. Yet even Mulder and Scully would have difficulty coming up with a scientific conspiracy based on these two, very small studies. Both studies took coral, placed them into aquaria or in the case of the Italians, put them into bags and added chemicals... Following that sort of methodology, we reckon that if you took some coral, put it into bag with seawater, urinated in it and then waited a few weeks, you'd end up with a bag of dead coral floating in some very smelly fluid. We could then conclude that human urine kills coral and demand that everyone is prevented from peeing in the ocean. In fact let's stop everyone, everywhere from peeing at all – you can't be too careful with environmental contaminants can you?
Anyway, what to do. Well we'd never tell anyone what to do, we only tell you what we will do which is this; when we go snorkelling in the summer we will be going out in the sun because we don't want to die from vitamin D deficiency and we will be wearing sunscreen because we don't want our heads to turn into giant mutant freckles. What you do is up to you but we would point out one thing, the science regarding sunscreens destroying coral is, as many experts point out, interesting but very limited and inconclusive. The science around skin cancer however, is rather more convincing and there is helluva lot more of it.
Oh by the way, despite what a great many people seem to think, the American Institute of Dermatology points out that there is no evidence to suggest that Oxybenzone is harmful to humans in anyway and is one of the only compounds that effectively protects against UVA and UVB. Zinc Oxide and Titanium Dioxide on the other hand, despite been lauded by many as safer alternatives to chemicals such as Oxybenzone, are non-biodegradable and are damaging to a variety of marine life – so we won't be believing all that marketing garbage either.
2008 research full paper (good luck with that)
And if you interested here's a science paper on the possible hormonal effects of sunscreens on humans – Mulder get Scully there's a conspiracy to look at!