Over the past decade, there has been a lack of awareness regarding certain sunscreens increasing the risk of skin cancer. Additionally, some sunscreens are effective against getting sunburned or photo-aging due to direct exposure to UV light [1]. To lessen the possibility of such dangers, both organic and inorganic filters are used to “absorb UVB and UVA II rays, resulting in a photochemical excitation and absorption of energy. Upon return to ground state, the absorbed energy results in emission of longer wavelength radiation and decreased skin penetration of radiation which reduces the risk of DNA damage” [2].
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Thus, with the potential of reducing the chance of developing skin cancer, UV filters like Oxybenzone, also known as benzophenone-3 (BP-3), are integrated in certain sunscreens and other dermatological care products. Although we utilize it to stay protected from harmful ultraviolet rays, oxybenzone is incredibly detrimental to marine life, including coral, sea anemone, and other keystone species. Oxybenzone is a moderately hydrophobic molecule, so when it is in the water, the compound latches onto and subsequently goes inside the hydrophilic interior of a marine organism (most frequently in coral). Once inside the being, oxybenzone is metabolized into glycoside conjugates, with the glucose provided by the coral’s symbiont algae. These metabolites of oxybenzone are extremely harmful and are what makes the UV filter a hormone disruptor by changing genetic material. Thus, “oxybenzone poses a hazard to coral reef conservation and threatens the resiliency of coral reefs to climate change” [4].
As a Stanford research group finds, the algae protect the animals by sequestering phototoxic oxybenzone metabolites. The overall phototoxicity depends on the balance in the animal tissue between screening of UV light by oxybenzone and photosensitization by its glucoside metabolites. Phototoxicity is when the skin or parts of an organism become sensitive to sunlight, which can cause additional problems. However, “if the symbiotic algae of corals and other anthozoans (class of marine invertebrates) indeed protect them from the toxic effects of oxybenzone metabolites, then the widespread bleaching of corals in response to rising seawater temperatures will make them more susceptible to oxybenzone-induced phototoxicity” [5]. Climate change is causing the coral to expel their algae unnecessarily.
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Additionally, oxybenzone is known to be a hormone disruptor. In the body, it mimics estrogen, interfering with different hormone processes [6].
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Recently, Hawaii prohibited any sunscreens with UV filters like oxybenzone and octinoxate from being sold. However, this ban only includes the sunscreens sold in Hawaii. Since many tourists bring items from their location of residence, such inimical sunscreens are still being used to this day and in large quantities. Even common waste water plant treatment techniques have not been able to effectively remove oxybenzone from the environment.
Current methods for oxybenzone detection and quantification are extremely involved and use liquid chromatography-tandem mass spectrometry (LC-MS/MS) which can separate different UV filters based on concentration and ionization [9].
[1] HW;, S. S. L. L. (n.d.). Review of Environmental Effects of Oxybenzone and other sunscreen active ingredients. Journal of the American Academy of Dermatology. Retrieved August 21, 2022, from https://pubmed.ncbi.nlm.nih.gov/29981751/
[2] U.S. National Library of Medicine. (n.d.). Oxybenzone. National Center for Biotechnology Information. PubChem Compound Database. Retrieved August 21, 2022, from https://pubchem.ncbi.nlm.nih.gov/compound/Oxybenzone#:~:text=Oxybenzone%20 absorbs%20 UVB%20and%20 UVA,the%20risk%20of%20DNA%20 damage.
[3] How UV radiation increases skin cancer risk. Cancer Council NSW. (2021, June 21). Retrieved September 30, 2022, from https://www.cancercouncil.com.au/cancer-prevention/sun-protection/understanding-uv-radiation/how-uv-radiation-increases-skin-cancer-risk/
[4] Downs CA;Kramarsky-Winter E;Segal R;Fauth J;Knutson S;Bronstein O;Ciner FR;Jeger R;Lichtenfeld Y;Woodley CM;Pennington P;Cadenas K;Kushmaro A;Loya Y; (n.d.). Toxicopathological effects of the sunscreen UV filter, oxybenzone (benzophenone-3), on coral planulae and cultured primary cells and its environmental contamination in Hawaii and the U.S. Virgin Islands. Archives of environmental contamination and toxicology.
[5] Conversion of oxybenzone sunscreen to phototoxic glucoside ... - science. (n.d.). Retrieved August 21, 2022, from https://www.science.org/doi/10.1126/science.abn2600
[6] Restoring progesterone for hormonal balance. Women's Health Network. (2021, July 6). Retrieved October 2, 2022, from https://www.womenshealthnetwork.com/hormonal-imbalance/sunscreen-ingredients-that-mess-with-your-hormones/#:~:text=Oxybenzone%20%2D%2D%20filters%20UV%20rays,avoiding%20sunscreens%20that%20contain%20oxybenzone.
[7] Molecular Mechanisms for the Function of Estrogen Receptors. (n.d.). Retrieved October 1, 2022, from https://researchgate.net/figure/Molecular-mechanisms-for-the-functions-of-estrogen-receptors-Genomic-pathway-Estrogen_fig1_296468111
[8] Structure and Mechanisms of an Estrogen Receptor. (n.d.). Retrieved October 1, 2022, from https://www.researchgate.net/figure/Structure-and-mechanisms-of-action-of-the-estrogen-receptor-ER-A-The-evolutionarily_fig2_318413263
[9] Bratkovics, S., & Sapozhnikova, Y. (2011, November 3). Determination of seven commonly used organic UV filters in fresh and saline waters by liquid chromatography-tandem mass spectrometry. Analytical Methods. Retrieved October 1, 2022, from https://pubs.rsc.org/en/content/articlelanding/2011/ay/c1ay05390f