Sunscreens Promote Coral Bleaching by Stimulating Viruses

This would be a good point at which to suggest some more earth-friendly sunscreens for those of us who wear it daily in order to ward off the Big C. I'm happy to trade in for non-or-less-polluting sunscreen, but this article makes it sound like that sort of thing doesn't exist.

I'm off to google now.

the first google hit, for those who are interested:

http://www.pristineplanet.com/biodegradable-organic-sunblock-natural-non-toxic-eco-friendly/sunscreen/1314_a_0.html

How about just basic zinc oxide? It doesn't look cool but it definitely blocks the sun...

There are a lot of sunscreens at my eco-stores, but I'm not sure what they actually contain. I'll have to read up on them before summer.

The fact that we smear them over our bodies can't be good for us either. I think I saw a television program about a tourist snorkeling or diving attraction, and everyone had to shower and put on supplied sunblock in order to prevent nasties from entering the water. Good for them! Let's keep this model in mind when we are playing in nature.

Are we going to see "Coral Friendly" certification? Hope so.

Suncreens with Titanium dioxide don't have these problems, and are healthier for your skin too. A high quality one (Dr Hauschka is my favorite) will blend and perform as well as your synthetic sunblocks!

As a marine scientist, an avid diver for over 45 years - I'm all for conserving the marine environment from human abuse. However, the science behind this particular sunscreen/coral bleaching research is extremely weak, incomplete and its conclusions neither demonstrated nor supported. The point of my comments herein is not to deny our coral reefs are not in danger, but to put this particular research in perspective critically and scientifically and to point out why its conclusions are not supported.

Here's a key quote from the research paper in question "We tested sunscreen (10 μL L-1) containing concentrations of UV filters higher than those reported in most natural environments." Actually, its massively higher than is likely to ever occur in ambient seawater in reef areas considering the relative an enormous dilution factors involved. Another fatal flaw in the research is that there is no large scale sampling from reefs around the world were accomplished to determine if sunscreen ingredients can even be detected in those waters or to correlate sunscreen use proximity with coral bleaching. The author says "Chemical compounds contained in sunscreens and other personal care products have been demonstrated to reach detectable levels in both fresh and seawater systems (Daughton and Ternes 1999; Giokas et al. 2007)." This statement is simply untrue - read the references listed. Both references offer very general extrapolated information and are not based (at least regarding coral reefs) on any specific insitu chemical analytical data. As such, neither reference provides any scientifically verified evidence of a direct link between sunscreen agents being measured in the seawater around reefs experiencing bleaching. Separating the effects of sunscreen from other far greater levels of other environmental pollution, or weather related stress events is not documented or well established in this research.

If the author had shown detectable levels of sunscreen ingredients (those ingredients that are not naturally found in background levels of seawater) in coral reef areas experiencing high levels of bleaching and in close proximity to sunscreen sources (sun bathing beaches) then a cause and effect relationship would have been supported - but it wasn't. If the researchers had shown a proximity correlation map of sun bathing beaches, or snorkeling areas to reefs with high levels of bleaching that would also have helped to establish cause and effect relationships to support their theory - but they didn't. What the researchers don't mention is that many of the same chemicals found in sunscreen are found in many shampoos and body washes all of which end up in up in sewage and a lot which eventually finds its way into the oceans of the world. These products are used in many orders of magnitude greater than sunscreen around the world (including coral reef tourist areas) because they are used daily rather than just during weekends or annual vacations. Many high density tourism areas around the world use ocean outfall systems to dispose of their sewage, or near shore septic systems where the liquid fractions of treated sewage end up in the water table and as run off. Coral bleaching to the best of my knowledge has never been correlated to diver frequency/density (divers are the only people that are likely to be in close proximity to corals) - though physical damage to corals has been. Instead coral bleaching is occurring in wide spread areas both remote and highly trafficed. Why the researchers single out sunscreen products rather than the more obvious pollution sources of these chemicals to research - is not explained or well justified.

The supposition that sunscreen agents actually change the outcome of the viral epidemiology is also not well supported by science - and or typical viral epidemiology. Stress in general may decrease host immune function and increase viral infection rates and virulence in the short term, but the long term virulence effects are generally mediated by the virus and the host itself - otherwise you would have massive viral related species extinctions which only rarely if ever occur. That's why the "promotion of viral infection" research theory is also not supported by general viral infection observation - other than as a potential and theoretical short term effect. Coral bleaching is a long term problem - and as such in my opinion a sunscreen/viral causal agent isn't a significant probability for its primary cause. This in turn makes the conclusion that sunscreen is a significant factor in coral bleaching questionable as well.

The authors conclusions "We conclude that sunscreens, by promoting viral infection, can potentially play an important role in coral bleaching in areas prone to high levels of recreational use by humans." are neither valid or supported scientifically, they are rather the author's theories. While pieces of this research are informative - they are informative only under the exact conditions under which they were demonstrated - improbable levels of sunscreen contaminants. Essentially they don't support any conclusion other than in the experimental environment described in the research - that the experimental levels of various sunscreen ingredients produce increased short term viral activity.

My point here is that while all pollution is a significant factor in environmental degradation and that residual pharmaceutical and personal care products in sewage are of particular concern and may well play a significant world wide role in marine environment degradation, incomplete research with exaggerated conclusions does not help the environment or environmentalism. It does promote the "Peter and the Wolf" syndrome that wears down the public, environmental managers and regulators, keeping them from making scientifically well informed decisions.

So where does that leave us as responsible stewards of the diving environments. If you're diving in coral reef areas - wear sun protective gear rather than sunscreen - I think this most of us do this already. If you are swimming at a beach miles from any reef - use the minimal amount of sunscreen required to protect yourself based on your health risk factors. Always use the minimal amounts of personal care products necessary to accomplish their purpose and good health in general. If you aren't a diver - avoid the coral reef areas of the world. If you are just a sun and beach person visit the sandy beaches in areas that don't support coral reefs. Reefs around the world are getting way to much use and abuse from people who don't know and care that they are even there. When your vacation is over - support responsible marine science research. Critically distinguish between literature that supports its conclusions scientifically and those that don't. Think critically in all things. Ask questions and ask again if the answers don't make sense. Be aware of the motivation of all informers. Be certain that you are well informed.

I have absolutely no beneficial relationship with anyone or companies producing sunscreens or related products. If you would like to read other critical commentary on this particular resource hear is an excellent one unrelated from mine.
http://aspiringecologist.blogspot.com/2008/02/sunscreen-and-coral-research-and.html

I think Durwood makes a valid point in asserting that sunscreens are probably not the only culprit at play here. And perhaps more research is needed to ascertain how much of an impact sunscreen plays. In the meantime, however, it's far safer to assume that manmade chemicals impact our environment in ways we're only just beginning to understand and to err on the side of caution. There are biodegradable and/or organic sunscreens out that there (from manufacturers such as SmartShield, Kiss My Face and Nature's Gate) are much safer for our environment and our health. We'd be wise to use them.

I think Durwood makes a valid point in asserting that sunscreens are probably not the only culprit at play here. And perhaps more research is needed to ascertain how much of an impact sunscreen plays. In the meantime, however, it's far safer to assume that manmade chemicals impact our environment in ways we're only just beginning to understand and to err on the side of caution. There are biodegradable and/or organic sunscreens out that there (from manufacturers such as SmartShield, Kiss My Face and Nature's Gate) are much safer for our environment and our health. We'd be wise to use them.

I do believe the typical sunscreen chemicals pose a very serious risk. I read an article about The Centers of Disease Control issuing a report stating that 97% of Americans are toxic and being poisoned by chemical sunscreens. Since they are absorbed into the skin, I think we all should be more cautious about our own health and that of the planet. The sunscreen I like is available through an organic, green company, Chae Organics. I usually just call their customer service line at 719-742-5288 but you can also find one of their sunscreens on line at chaeorganics.biz ---- I don't sell the stuff but my salon recommended it and that all I use on my children and on myself.

This article is absolutely correct about how damaging traditional sunscreen can be to our environment. In addition to being bad for coral reefs, you can imagine how terrible it is to slather all of those chemicals directly on your skin, which can absorb them directly into your bloodstream! After much research, I found tons of different kinds of sunscreens which claim to be natural, but upon turning the package over, you can see that they still contain some of the most harmful chemicals around. The only sunscreen I found that had a decent SPF rating (SPF 25) and absolutely no chemicals is called Caribbean Solutions. This sunscreen uses Titanium Dioxide and Zinc Oxide (natural minerals) to provide physical protection from both UVA and UVB rays. I had been purchasing it at Whole Foods, but recently found it available on Target.com as well. Try this sunscreen, you will love it!