PracticeUpdate: Dermatology - Winter 2018

EDITOR’S PICKS 10

Toxicological Impact of the Sunscreen Ingredient Oxybenzone/Benzophenone-3 Journal of Cosmetic Dermatology Take-home message • The environment effects of commonly used organic UV filters have become a pressing topic. Organic UV filters have been identified in water sources worldwide, with oxybenzone noted as the most frequently detected in the largest concentrations. Organic filters are prevalent in waste from sunscreen and cosmetic manufacturing facilities. These filters are not easily removed by common waste treatment plant techniques. Oxybenzone has also been shown to contribute to coral reef bleaching. Further- more, 4-methylbenzylidene camphor, oxybenzone, octocrylene, and octinoxate have been identified in various species of fish worldwide, which may have consequences for the food chain. • These authors suggest potential solutions to reduce environmental toxic effects of organic UV filters, which include seeking shade; wearing photoprotective clothing, wide-brimmed hats and sunglasses; and using sunscreens with inorganic filters (titanium dioxide and zinc oxide).

COMMENT By Robert T. Brodell MD, FAAD T his article was certainly stimulating! Written by a national leader in this field, Henry Lim, MD, it details the facts: 1) oxybenzone from sunscreen use and manufacture is detectable in oceans, swimming pools, and lakes; 2) oxyben- zone can destroy coral by bleaching; and 3 4-methylbenzylidene camphor, oxybenzone, octocrylene, and octinoxate have been identified in fish. With regard to coral, studies have shown damage to coral in the immediate vicinity of beaches where sunscreens have been worn by thousands of swimmers. However, the concen- trations after dilution in the ocean should not affect the Great Barrier Reef…the type of destruction that would be expected to seriously harm the ecosystem. There is no evidence that these chemicals in sunscreen are harming humans in the concentrations to which we are exposed. Still, should we err on the side of caution and ban the use of these products? I believe that would be premature. The alter- native physical block sunscreens are hard to rub onto the skin and leave a white residue. There have been fears raised about the nanoparticles in these agents. On the other hand, the phys- ical sunscreens do not get into the eyes with sweating, causing stinging and burning like many of the chemical sunscreens. The evidence is not all in; but, for now, it is abundantly clear that sunscreens, as part of a multimodal effort, can reduce actinic keratoses, skin cancer, wrinkles, and solar lentigines. I will continue to recommend to my patients that they wear a hat, use an umbrella and other sun-protectant shelters, and wear the sunscreen SPF 30 or greater that they like best. I believe that the difficulties with patient adherence to the use of sun- screens make this the best approach for now. For individuals worried about their vitamin D levels, I also recommend 2000 international units (IU) of vitamin D daily. Finally, the Food and Drug Administration (FDA) should rapidly consider the safety and efficacy of broad spectrum chemical sunscreens available in Europe so that American consumers have as many options as possible should evidence lead to elim- ination of oxybenzone/benzophenone-3 from the marketplace.

Abstract Oxybenzone (Benzophenone-3) is an emerging human and environmental contaminant used in sunscreens and personal care products to help mini- mize the damaging effects of ultraviolet radiation. The Center for Disease Control fourth national report on human exposure to environmental chemicals demonstrated that approximately 97%of the people tested have oxybenzone present in their urine, and independent scientists have reported various con- centrations inwaterways and fishworldwide. Oxybenzone can also react with chlorine, producing hazardous by-products that can concentrate in swimming pools and wastewater treatment plants. Moreover, adverse reactions could very well be increased by the closed loop of ingesting fish contaminatedwith oxybenzone and/or washing the ingredient off our bodies and having it return in drinking water as treatment plants do not effectively remove the chemi- cal as part of their processing protocols. In humans, oxybenzone has been reported to produce contact and photocontact allergy reactions, implemented as a possible endocrine disruptor and has been linked to Hirschsprung's dis- ease. Environmentally, oxybenzone has been shown to produce a variety of toxic reactions in coral and fish ranging from reef bleaching to mortality. Lastly, with the rise in skin cancer rates and the availability of more effective sunscreen actives such as micronized zinc oxide and titanium dioxide, seri- ous doubts about the relative prevention benefit of personal care products containing oxybenzonemust be raised and comparedwith the potential neg- ative health and environmental effects caused by the accumulation of this and other chemicals in the ecosystem. Dermatological and Environmental Toxicological Impact of the Sun- screen Ingredient Oxybenzone/Benzophenone-3. J Cosmet Dermatol 2018 Feb 01;17(1)15-19, JC DiNardo, CA Downs. www.practiceupdate.com/c/70634

PRACTICEUPDATE DERMATOLOGY