A Critical Review of Organic Ultraviolet Filter Exposure, Hazard, and Risk to Corals

Abstract There has been a rapid increase in public, political, and scientific interest regarding the impact of organic ultraviolet (UV) filters to coral reefs. Such filters are found in sunscreens and other consumer products and enter the aquatic environment via direct (i.e., recreational activities, effluents) or indirect (i.e., land runoff) pathways. This review summarizes the current state of the science regarding the concentration of organic UV filters in seawater and sediment near coral reef ecosystems and in coral tissues, toxicological data from early and adult life stages of coral species, and preliminary environmental risk characterizations. Up to 14 different organic UV filters in seawater near coral reefs have been reported across 12 studies, with the majority of concentrations in the nanograms per liter range. Nine papers report toxicological findings from no response to a variety of biological effects occurring in the micrograms per liter to milligrams per liter range, in part given the wide variations in experimental design and coral species and/or life stage used. This review presents key findings; scientific data gaps; flaws in assumptions, practice, and inference; and a number of recommendations for future studies to assess the environmental risk of organic UV filters to coral reef ecosystems. Environ Toxicol Chem 2021;40:967–988. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Abstract Limited and variable ultraviolet (UV) filter monitoring data in coral reef environments in conjunction with limited toxicity information with significant methodological issues have led to limited and unreliable risk assessment of UV filters to corals. It is our recommendation that increased monitoring and toxicity testing along with harmonized guidelines for coral toxicity testing and risk assessment calculation would help alleviate these issues.