What are the environmental effects of oxybenzone and other sunscreen ingredients?
Acta Eruditorum
Dr. Schwarzenberger is the former physician editor of DermWorld. She interviews the author of a recent study each month.
By Kathryn Schwarzenberger, MD, October 1, 2018
In this month’s Acta Eruditorum column, Physician Editor Kathryn Schwarzenberger, MD, talks with Henry W. Lim, MD, and Samantha L. Schneider, MD, about their recent Journal of the American Academy of Dermatology article, “Review of environmental effects of oxybenzone and other sunscreen active ingredients.”
Dr. Schwarzenberger: Drs. Schneider and Lim, your beautifully written review on the environmental effects of oxybenzone and other active sunscreen agents both wowed and concerned me. I hope our readers all take the time to read this thought-provoking article. Can you summarize your key findings here?
Dr. Lim: Our article summarizes the reported biologic and environmental effects of oxybenzone and several other chemical ultraviolet filers. Hormonal effects have been shown in animal models following oral administration. However, there are no known similar effects that are relevant in humans. Oxybenzone has been associated with bleaching of coral reefs in laboratory settings. In nature, the reason for coral reef bleaching is multifactorial, with the warming of ocean water considered to be a major contributor. Oxybenzone has also been detected in water sources worldwide, as well as in fish. These concerns have led to the banning of oxybenzone- and octinoxate-containing sunscreens in Hawaii, effective January 2021.
Dr. Schwarzenberger: Some of the studies you cite in your review date back a number of years; the study from Switzerland that found UV filters accumulating in fish is more than 10 years old. Why is this issue now getting such attention? Is coral reef bleaching the bellwether?
Dr. Schneider: The paradigm shift from the importance of strict photoprotection with chemical UV filters, to the impact of these filters on the environment and the potential risks of these filters to humans is large. Over the last 10 years, there have been more studies to support the notion that chemical UV filters are negatively affecting our environment. While there has been no clear evidence on the negative impact on humans, the potential should not be ignored. I think that coral reef bleaching was the nidus for this shift. Coral reef bleaching has received a lot of attention in the mainstream media and from environmental activists because coral reefs are an enormous ecosystem that is important in the ocean’s homeostasis.
Dr. Schwarzenberger: Do you believe sunscreen products are the main source of UV filters in ocean waters? Your article mentioned a study that indicated that as many as 14,000 tons of sunscreens are released annually into coral reef areas. Is this all from swimmers, or might industrial waste be contributing?
Dr. Schneider: Sunscreens are an important contributor to UV filters in our water supply as they have become widely used for protection from the harmful effects of UV radiation. Sunscreens enter the water not only through people’s swimming in lakes or oceans but also through our plumbing (showers and toilet use) and via industrial waste. In addition to sunscreens, chemical UV filters have been added to many personal care products that enter the water supply via similar mechanisms. Swimming definitely contributes, but so does using sunscreen for any other activities, including daily use. As a whole, we should try to be more aware of what is in the products that we are using and ask ourselves whether or not we are contributing to the presence of these filters in our water.
Dr. Schwarzenberger: What do we know about UV filters used in plastics?
Dr. Schneider: This is a great question. UV filters are integrated into many plastic-based products such as sheeting on windows and glass on picture frames to protect people, photographs, and artwork from ultraviolet radiation. These are commercial products, and the exact filters are often not disclosed, so it is difficult to know exactly which UV filters are used. These products could be a potential industrial source of UV filters in the water supply. As the movement toward avoiding chemical filters continues to grow, I imagine that industry may feel pressure to disclose their filters — and if they are using some of these culprit filters — adjust their formulations to meet our growing call for environmental awareness.
Dr. Schwarzenberger: Several of my patients over the years have expressed concern about the safety of oxybenzone and I, probably like most dermatologists, reassured them that sunscreens are safe. Do you think we could have anticipated this?
Dr. Lim: I agree that questions on the safety of oxybenzone have been expressed for several years. Like you, I was also skeptical about its biologic relevance when this topic initially surfaced years ago. However, as physicians, all of us are trained to make evidence-based decisions. On this issue, while we need to recognize that there is no data supporting a negative impact on human health, we need to accept the environmental data that have emerged in the past 10 years.
Dr. Schwarzenberger: Given what we know now, how do you counsel your patients about photoprotection?
Dr. Lim: As physicians, and as a professional organization, we and the American Academy of Dermatology need to maintain our credibility with our patients and the public. We all recognize the many physical and psychological benefits of outdoor activity. However, we all are also very well aware of the deleterious side effects of excessive UV exposure. As such, we need to continue to emphasize to our patients and the public the importance of photoprotection. We also need to explain our long-standing position on photoprotection, namely: seek shade when outdoors; wear photoprotective clothing, including wide-brimmed hats and sunglasses; and generously apply broad-spectrum, water-resistant sunscreen with an SPF of 30 or higher on exposed areas. Furthermore, those concerned about the potential environmental impact of chemical sunscreen ingredients can use mineral (also known as physical or inorganic) sunscreens containing zinc oxide or titanium dioxide.
Dr. Lim is the former president of the AAD and chair emeritus of the Henry Ford Hospital department of dermatology. Dr. Schneider is a dermatology resident at Henry Ford Hospital department of dermatology. Their article appeared in the Journal of the American Academy of Dermatology.