Samm, UR - Fear the Filter!

So, through research, I have learned that titanium oxide and zinc oxide can create hydrogen peroxide with help from UV radiation in the water. While these ingredients are not necessarily toxic to us in the form of sunscreen, this pair of ingredients can be hazardous to marine life. But zinc and titanium oxide are not the only UV filters out there, it got me thinking to other ingredients, such as octinoxate and oxybenzone.

The Environmental Working Group created a table on toxicity levels for the nine most commonly used sunscreen filters. They range from higher toxicity concerns to lower toxicity concerns. The EWG are basing these filters on their toxicity to humans; if they penetrate through the skin into our tissue, mess with our hormones, or cause skin allergies. Out of the five moderate to higher toxicity level filters, four were found in breast milk. All five penetrated the skin up to 1%, with the exception of oxybenzone, which sports the highest amount of skin penetration (anywhere from 1-9%). Funnily enough, titanium and zinc oxide have lower toxicity levels, so they aren't as harmful to us. 

Zinc and titanium oxide are the only ingredients on the table that were tested by the original study. According to an article by Women's Health magazine, chemical filters (such as octinoxate) can also produce free radicals that can damage our cells. It's funny that both the chemical filters and zinc and titanium oxide produce free radicals, and I have to wonder if the free radicals produced by the chemical filters have the same effect on the marine environment as the free radicals from the oxides. If this is true, than could it be possible that these chemical sunscreen filters could help make hydrogen peroxide in our ocean?

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I guess at this point, I would wonder what you might test your sunscreen on and how you would set up any experiment. Any thoughts?

I have been thinking about this for quite a while. At first, I thought I could take some seagrass samples from a couple of different locations, but I am unsure of what I would test for. I thought of just doing what was done in the original study, by taking water samples from different locations and testing for zinc and titanium oxide. Given what I learned from today's article, if I go down that road I might also test for other common sunscreen ingredients. I am still a little unsure of which road I want to go down.

Although, I think no matter what, I definitely want to test for hydrogen peroxide in the water.