By Jill Wirt, MESM '20
Recent headlines have people wondering what sunscreen they are allowed to use due to its effect on coral reefs. Many people, however, would rather worry about their skin than the corals. Most humans are removed from coral reefs and do not see the adverse effects oxybenzone has to reef populations around the world, making it difficult for them to switch from their favorite sunscreens. But what if I told you oxybenzone harms us, too?
Oxybenzone is a chemical commonly used in sunscreens as a shortwave (UVB) and longwave (UVA) radiation absorber. It is reported that oxybenzone is used in up to 2,000 personal care products spanning from skin and hair care to color cosmetics and fragrances.[i] Oxybenzone, though, is not as friendly as you might think. Between 6,000 and 14,000 tons of sunscreen enter the oceans each year[ii], indicating we humans are pretty good at lathering up to protect our skin against harmful UV rays. What isn’t visible though, and not commonly known, are the adverse effects oxybenzone has on our health.
By directly applying oxybenzone products to our skin, we are exposing ourselves to a harmful chemical and increasing its presence in the natural environment. Oxybenzone is a known skin allergen, named the 2014 Allergen of the Year by the American Contact Dermatitis Society, as well as a possible hormone disruptor.[iii] Other hormone disruptors include DDT, polychlorinated biphenyls (PCBs), and other pesticides. These disruptors, including oxybenzone, can cause birth defects, cancerous tumors, and other developmental disorders. Not only are humans at risk from directly applying oxybenzone products to the skin, but also through ingestion.
Oxybenzone can enter the environment, and possibly return to us, in two main processes: through directly swimming in the ocean, river, or pool (creating chlorinated oxybenzone which results in more cell death than unchlorinated chemicals) or through discharge of a wastewater treatment plant (WWTP).[iv] WWTPs are not effective in filtering out oxybenzone; not only will oxybenzone concentrations increase in the environment from WWTP effluent streams, but our drinking water is showing oxybenzone contamination as well. Oxybenzone has been found in urine, serum, and breast milk of individuals[v], implying that intake of oxybenzone is coming from more than just direct application of personal care products. Humans can also ingest oxybenzone from seafood, due to chemical accumulation in the food chain.[vi]
Marine animals are also suffering from oxybenzone exposure as it accumulates in the food chain. Fish are not only experiencing hormone disruption due to oxybenzone, but their habitat is rapidly decreasing as well. Oxybenzone exacerbates coral bleaching, a process that occurs when corals reject a symbiotic algae from their bodies, and in turn lose their main source of food.[vii] Corals are under a lot of stress due to increasing ocean temperatures and ocean acidity,[viii] making it nearly impossible for young corals to settle and survive in harsh conditions. A rapid decline in coral population has many adverse effects: loss of biodiversity, loss of economic revenue from tourism, loss of food for coastal communities, and loss of shoreline access due to large wave destruction.[ix] It is difficult to place a dollar amount on coral reefs, but it is evident many coastal communities will suffer without them. In order for humans to protect themselves and reefs, it is recommended to switch from chemical-based sunscreens to mineral-based sunscreens.
You may have to give up your favorite sunscreen; even places like Hawaii are passing legislation that bans the sale of oxybenzone products. But there are plenty of alternative, reef-safe sunscreens available. Mineral-based sunscreens containing non-nano zinc oxide and titanium dioxide are found to be more effective, if not the most effective, at blocking incoming UVA radiation.[x] It is important to keep in mind that sunscreen users will receive better protection from consistently reapplying sunscreen rather than choosing a higher SPF. For instance, a product with SPF 30 protects against 97% of UVB, whereas a product with SPF 50 protects against 98% of UVB. The higher SPF products also are more likely to contain more sunscreen actives, therefore increasing the chance of skin irritation.[xi]
Another solution to stop using chemical-based sunscreens is to wear protective clothing such as hats, sunglasses, and rash guards. Wearing these items reduces the need for sunscreen and usually offers better sun protection. By actively choosing to avoid oxybenzone, you are not only reducing harmful exposure to your body, but also helping the environment.
References
[i] Dinardo, Joseph C, and Craig A Downs. “Dermatological and Environmental Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3.” Journal of Cosmetic Dermatology, vol. 17, 29 Sept. 2017, pp. 15–19., doi:10.1111/jocd.12449.
[ii] Downs, C. A., et al. “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, vol. 70, no. 2, 20 Oct. 2015, pp. 265–288., doi:10.1007/s00244-015-0227-7.
[iii] Dinardo, Joseph C, and Craig A Downs. “Dermatological and Environmental Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3.” Journal of Cosmetic Dermatology, vol. 17, 29 Sept. 2017, pp. 15–19., doi:10.1111/jocd.12449.
[iv] Dinardo, Joseph C, and Craig A Downs. “Dermatological and Environmental Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3.” Journal of Cosmetic Dermatology, vol. 17, 29 Sept. 2017, pp. 15–19., doi:10.1111/jocd.12449.
[v] Dinardo, Joseph C, and Craig A Downs. “Dermatological and Environmental Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3.” Journal of Cosmetic Dermatology, vol. 17, 29 Sept. 2017, pp. 15–19., doi:10.1111/jocd.12449.
[vi] Dinardo, Joseph C, and Craig A Downs. “Dermatological and Environmental Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3.” Journal of Cosmetic Dermatology, vol. 17, 29 Sept. 2017, pp. 15–19., doi:10.1111/jocd.12449.
[vii] Glynn, Peter W. “Coral Reef Bleaching: Facts, Hypotheses and Implications.” Global Change Biology, vol. 2, no. 6, 1996, pp. 495–509., doi:10.1111/j.1365-2486.1996.tb00063.x.
[viii] Glynn, Peter W. “Coral Reef Bleaching: Facts, Hypotheses and Implications.” Global Change Biology, vol. 2, no. 6, 1996, pp. 495–509., doi:10.1111/j.1365-2486.1996.tb00063.x.
[ix] Larsen, M. C., & Webb, R. M. (2009). Potential Effects of Runoff, Fluvial Sediment, and Nutrient Discharges on the Coral Reefs of Puerto Rico. Journal of Coastal Research, 251, 189-208. doi:10.2112/07-0920.1
[x] Dinardo, Joseph C, and Craig A Downs. “Dermatological and Environmental Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3.” Journal of Cosmetic Dermatology, vol. 17, 29 Sept. 2017, pp. 15–19., doi:10.1111/jocd.12449.
[xi] Dinardo, Joseph C, and Craig A Downs. “Dermatological and Environmental Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3.” Journal of Cosmetic Dermatology, vol. 17, 29 Sept. 2017, pp. 15–19., doi:10.1111/jocd.12449.