Does sunscreen kill marine life? New research shows just how quickly it can become toxic in the ocean.
News article: https://www.cbsnews.com/news/sunscreen-marine-life-toxic-research/
Scientific publication: https://www-science-org.proxy.lib.umich.edu/doi/10.1126/science.abn2600
The article I read, “Does sunscreen kill marine life? New research shows just how quickly it can become toxic in the ocean.” is based on a 2022 publication from Science. The publication is a study aimed to determine whether oxybenzone is phototoxic to coral and anemones, and the mechanism behind its effects.
Some quick background: oxybenzone is a benzophenone derivative used as a sunscreen filter in chemical sunscreens. It’s already known to damage coral reefs and other wildlife, as previous studies have indicated that it's a potential endocrine disruptor and potentially phototoxic. Oxybenzone is banned in Hawaii, as sunscreen that washes off of the skin or is sprayed into the sand from aerosols contaminates the water with oxybenzone.
The article effectively summarizes the publication’s methods: sea anemones (Aiptasia) were exposed to 2 mg/liter of oxybenzone, with or without UV light. By the end of the trial, all of the UV-exposed anemones were dead, while the group without UV light survived. Analysis showed that the oxybenzone was metabolized into more toxic chemicals. Further trials tested the effects of oxybenzone and UV on mushroom corals, as well as anemones that lacked their symbiotic algae. The mushroom coral with algae survived, as the algae sequestered the toxins away from the coral. The anemones without algae died about twice as fast, and had about three times as many metabolites upon analysis. This means that bleached coral — coral that has expelled its algae, usually due to stress — are more vulnerable to oxybenzone.
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| Survival of aposymbiotic and symbiotic Aiptasia with or without oxybenzone and/or UV light |
The original publication also details the extent of the problem, such as studies that indicate how reefs exposed to more oxybenzone are faring substantially worse than those exposed to less oxybenzone. Unlike the online article, it also partially explained the use of anemones instead of coral - the genus of anemone used is a well-established model for studying symbiotic anthozoan cnidarians, of which coral belongs to. It also, understandably, was more detailed in describing the conditions used during the experiments. The article glossed over the processes that the researchers used to determine that the oxybenzone metabolite, which was mostly oxybenzone-glucoside, was phototoxic. In essence, the researchers wanted to determine if the phototoxicity was due to either excited triplet states, reactive oxygen species (ROS) or reactive halide species (RHS). They used chemicals that degrade in the presence of UV and are sensitive to these three mechanisms, and determined that oxybenzone decreased the rate of photodegradation, while the oxybenzone metabolite increased it. The concentration of oxybenzone metabolite remained the same, indicating that it catalytically generated reactive species.
The most important issue with the online article was an error in reporting the results from the initial trial with oxybenzone-exposed anemones with and without UV - it reported that all anemones died within ten days, but the publication states that it was within 17 days. The only other issue I found was that the article didn’t put the 2 mg/liter of oxybenzone into perspective for the reader. The publication mentioned that up to 1.4 mg/liter was found at a popular reef in the US Virgin Islands, but didn’t indicate how similar those numbers are to other areas.
Overall, I give the article a 8/10, because it effectively summarizes the article without leaving information that would factor into a reader’s interpretation of the results, and the only issue was the data point error and real-world levels of oxybenzone.
Thanks for sharing these articles! A common theme that seems to come up in our class and blog post discussions involves the substitution of a chemical with known toxicity for a chemical with unknown toxicity. Without external enforcement to phase out oxybenzone, the driving force for a company to change its sunscreen formulation is profit. If consumers do not purchase the product because of the oxybenzone content, then perhaps the company will change formulations. However, that does not guarantee that rigorous toxicity studies will be conducted. What do you feel is the best avenue to hold the sunscreen industry responsible for the unintended consequences of its products and ensure that chemical substitutions for oxybenzone do not further harm marine life?
ReplyDeleteI think the best way to hold them responsible is through regulation; the FDA has announced their intent to prepare an impact statement to assess the environmental impacts of sunscreen filters. Some areas, like in Hawaii, have also banned the use of all chemical sunscreen filters, leaving just zinc oxide and titanium dioxide as physical filters - which generally appear to be safer than organic filters for both humans and marine life. I don't think its likely that the sunscreen industry will replace oxybenzone with a new filter considering how long its been since a new filter has been FDA approved, and I imagine the other approved organic filters will be phased out as more research is done on them .
DeleteHi, Allison. Great work on this write up. I think this is super interesting research and after skimming through the scientific article, I didn't see any information about it but I may have missed if they mentioned anything regarding restricting oxybenzone in other places that are not directly coastal to the ocean. Something that maybe should be considered is how rivers/lakes feed into oceans, so really regardless of where you are the sunscreens could possibly get into the oceans. Is this something that has been considered in other research or is this something that is plausible to study in future studies? I think Madeline made a really good point that regardless, taking out a certain chemical really does come down to money so lobbying may be an important aspect to put into action for this type of research
ReplyDeleteOxybenzone can definitely feed into the oceans from rivers, but the concentrations in rivers is generally not nearly the level thats seen in the oceans - the high levels in the oceans is due to the high concentration of people and how often they're heavily populated. And, the high levels are usually very close to coral reefs, so that's why theres more focus on lowering the levels found in those areas.
DeleteHi Alison, I really enjoyed reading these articles. The only issues I took with them were similar to yours. I would have really liked to see the CBS article explain why the researchers chose to use a concentration of 2 mg/L since they chose to mention the specific amount in the article. I was wondering what you think the impact of misreporting the number of days it took for the exposed anemone to die would be on a general audience. While reporting the correct numbers is obviously important, would 10 versus 17 days have a different impact on the reader?
ReplyDeleteI think the 10 day data point might make the reader believe that the anemone/coral's response to the oxybenzone is more extreme than they'd believe if the correct 17 days had been published, but I'm not sure how much of an impact that would make since the reader already doesn't have context for how high 2 mg/L is compared to the real world. I've done more research on oxybenzone for my poster project, and 2 mg/L appears to be a fairly 'normal' dose, considering that studies on coral seem to range between 1-3 mg/L depending on the species studied, but it would still be nice to know why they specifically chose 2 mg/L.
DeleteHi Allison thanks for sharing these articles! I noticed at the end of the CBS article they mentioned how "many alternative sunscreen formulas thought to be safer for marine life have chemicals similar to oxybenzone, meaning that they could just be adding to, rather than solving, the problem". I was wondering if the companies making these products with false claims were aware of that, and if anything is really being done about it?
ReplyDeleteI think the main issue is that there really isn't enough data on the toxicity of sunscreen filters; oxybenzone is actually the most researched organic UV filter and yet there are still many unknowns and knowledge gaps - so imagine how little is known about alternative filters! I think it's important for the public to know that the 'reef safe' claim (seen on sunscreens that don't contain oxybenzone, octinoxate, or ocytocrylene, usually) isn't at all regulated by any government agency, so its really best to do your own research. In Maui County in Hawaii, all organic/non mineral UV filters are actually banned completely, so that's one solution to the potential for 'adding to the problem.' Unfortunately, mineral sunscreens also have an effect on marine life, so at the moment it seems there isn't a perfect course of action for keeping the reefs safe and protecting from the sun.
DeleteHi Alison, I am curious, are there any sunscreens currently out there that do not release oxybenzones or similar chemicals? Would any washable UV screen that has a similar chemical makeup give the same response towards the coral reefs and other wildlife? Would any washable UV screen at all give the same response towards the coral reefs and other wildlife?
ReplyDeleteThank you for sharing these articles! I am curious if you think it is advantageous for the news article to potentially include a discussion on using model organisms for this study or do you think it would just cause confusion? Is a middle ground potentially more appealing?
ReplyDeleteHello, Thanks for sharing the article! Regarding to your discussion about reporting 2mg/L, do you think maybe it will be more appropriate for the author to neglect this data or use an alternative form of reporting it? Since the general public might not have an idea about actual amount of 2mg/L, I think the author can use "the size of a dime of sunscreen" is large enough to kill to anemones. Just some thoughts, what do you think?
ReplyDeleteHi Alison,
ReplyDeleteReally fascinating article choice, I had no idea that sunscreens were toxic to aquatic life! Out of curiosity, I looked up oxybenzone-free sunscreens and there luckily seems to be a large number of products and market for them. However, the article specified that general excited-state proton transfer mechanisms of energy-dissipation, as is the mechanism of oxybenzone sunscreens, would likely provide the same toxic effect; do you know of any other sunscreens that utilize different energy-dissipation mechanisms?
Hi Alison! This is a sweet topic- I am particularly interested in it because I study photochemistry. You mentioned reactive oxygen species are involved in the oxybenzone/UV/photodegradation relationship here. Do ROS stimulate the degradation of oxybenzone? I am curious if you have any more insight to that portion of the discussion.
ReplyDeleteHey Alison! Great picks! I was wondering if you thought the news article lacked any information on the importance of coral reefs on marine life? I think a bit of background could have been helpful for people to understand why coral bleaching is so detrimental to marine biomes.
ReplyDeleteGreat article! Because the composition of the sea is different in different areas, and this paper only touched on the sea near Hawaii, I wonder if the same sunscreen could have similar effects in a place like Australia. I know that oxybenzone is likely a universal toxin (so it would kill sea anemones regardless of the water composition), but could different factors like salinity or temperature increase or decrease toxicity?
ReplyDeleteHi Alison, great choice of topic and articles! I agree that the article did a good job touching on the major points of the scientific paper. One line in the news article stood out to me: "Today, many alternative sunscreen formulas thought to be safer for marine life have chemicals similar to oxybenzone, meaning that they could just be adding to, rather than solving, the problem." There are some sunscreens (such as mineral sunscreens) that are generally considered safer for marine life that oxybenzone containing ones. Do you think that including a line with generally safer, but not perfect, sunscreen alternatives would assist readers in their future purchasing decisions?
ReplyDeleteI actually would disagree with your rating to a certain extent. This is in particular due to the inaccurate reporting of results surrounding anemone that is not just a rounding error, but a true misreporting. That combined with the missing context for some statistics and the other things you point out make it seem like 8 is a little generous for this article.
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