UV filters and their impact on marine life: state of the science, data gaps, and next steps

Abstract

Sunscreens containing broad‐spectrum ultraviolet (UV) filters play an essential role in protecting the skin against the damage induced by sun overexposure. However, the widespread use of sunscreens and other personal care products containing these filters has led to these compounds being widely detected in the environment and being identified as emerging pollutants in marine waters. Concerns raised by laboratory studies investigating the potential impact of UV filters on coral communities have already led to bans on the use of some sunscreens in a few tourist hotspots. Although UV filter pollution may be just one of the many environmental factors impacting coral health worldwide, the media attention surrounding these studies and the legislative changes may lead patients to question dermatologists about the environmental safety of some sunscreen products. This review provides an overview of current knowledge on the impact of UV filters on marine ecosystems, concentrating on recent studies examining the effects of commonly used filters on organisms at low trophic levels and of how alternative approaches, such as metabolomics, can be used to further assess UV filter ecotoxicity. Current gaps in our knowledge are also discussed, most notably the need to increase our understanding of the longer‐term fate and behaviour of UV filters in the marine environment, develop more adapted standardized ecotoxicity tests for a wider range of marine species, and evaluate the impact of UV filters on the marine food web. We then discuss future perspectives for the development of new, more environmentally friendly, filters that may enable the use of the most toxic compounds to be reduced without compromising the effectiveness of sunscreen formulations. Finally, we consider how dermatologists play a key role in educating patients on the need for a balanced approach to sun exposure, sun protection, and conservation of the marine environment.

Highlights from the Journal of the European Academy of Dermatology and Venereology in 2022

“…Nevertheless, in our efforts to promote photoprotection, we must equally consider the environmental consequences: UV filters, especially homosalate and benzophenones, have been found to be seriously harmful to marine life. 10 There is a need for research towards better, more environmentally friendly sunscreens. In advocating for climate change, JEADV has joined other major international dermatology journals in urging academic organizations to move beyond research and education, as well as in their day-to-day operations, including reduction in the carbon footprint of events such as conferences and congresses.…”

“…Nevertheless, in our efforts to promote photoprotection, we must equally consider the environmental consequences: UV filters, especially homosalate and benzophenones, have been found to be seriously harmful to marine life 10 . There is a need for research towards better, more environmentally friendly sunscreens.…”

Reef safe sunscreens: A call to action

“…1 In addition to these, environmental scientists have labelled certain ultraviolet radiation (UV) filter ingredients as 'contaminants of emerging concern' due to their potential to damage coral reefs. 2,3 This has sparked media-driven public attention and raised questions in minds of consumers regarding the overall safety profile of sunscreens, despite the clearly known health benefits of sunscreen use in reducing the incidence of squamous cell carcinoma and melanoma by 40% and 50%, respectively. 3 Ultraviolet filters can reach aquatic environments via direct wash-off from swimmers or indirectly from incomplete wastewater treatment.…”

“…8 Studies have demonstrated that nanoparticles of inorganic UV filters like titanium dioxide and zinc oxide can also have toxic effects on marine microalgae and zooplankton. 2,5 Only 15 of the 60 permitted UV filters worldwide have been tested for toxic effects on the marine environment, and thus, there is limited safety evidence for several UV filters. Thus, at present 'reef safe' labelling should be interpreted with caution since it has not been validated and is not scientifically justified.…”

“…3 Ultraviolet filters can reach aquatic environments via direct wash-off from swimmers or indirectly from incomplete wastewater treatment. 2 Downs et al showed that swimmers and beach showers were the main sources of water contamination with oxybenzone and this posed a serious threat to the coral reef system in Hanauma Bay in Hawaii. 4 Oxybenzone and octinoxate are organic UV filters that are photo-unstable and quickly break down into harmful byproducts and free-oxygen radicals that can cause genotoxicity, significant shifts in the coral metabolome, endocrine disruption and eventually lead to coral bleaching and death.…”