Ecotoxicological effects of sunscreen derived UV filters on temperate marine organisms

Ultraviolet (UV) filters are active compounds which absorb, block, or scatter UV radiation, and are added to personal-care products (PCPs), such as sunscreens and cosmetics, to protect against photoaging and photocarcinogenesis. UV filters can be mineral-based (inorganic) or chemical-based (organic) and are considered contaminants of emerging concern (CEC) due to their widespread use and ubiquitous presence in the environment. UV filters can enter the marine environment through various pathways, including direct skin wash-off, wastewater effluent and industrial spills.  

UV filters have been detected globally in wastewater, freshwater and marine environments; and have been recorded in multiple matrices including accumulation within aquatic biota, sediments and water columns. Media attention has particularly focused on the effects of sunscreens on corals in recent years; resulting in regulatory implementation on such compounds in areas such as Hawaii and Palau; however, very little research has been conducted on the effects of these compounds on temperate marine organisms.  

Adopting a multidisciplinary approach, this research highlights the ecotoxicological effects of two contrasting sunscreen derived UV filters (benzophenone-3 and nano-titanium dioxide) on temperate marine organisms; including Isochrysis galbana and Mytilus galloprovincinalis, and analyses the potential of these compounds to bioaccumulate and undergo trophic transfer. The ecotoxicological effects are elucidated at a molecular, cellular and individual level.  

Here, we subjected Isochrysis galbana to varying environmentally relevant concentrations of benzophenone-3 and nano-titanium dioxide in a series of experiments under ultraviolet lighting. Ecotoxicological effects including cell viability, growth, chlorophyll-a content, dimethylsulfoniopropionate (DMSP) concentration, oxidative stress markers, enzymatic activity and bioaccumulation was assessed using a range of techniques including flow cytometry, fluorescence, electron microscopy, gas chromatography, LC-MS and ICP-MS. Results so far have indicated that both benzophenone-3 and nano-titanium dioxide can result in significant effects to cell density and chlorophyll-a content, whilst nano-titanium dioxide can cause oxidative stress in the form of lipid peroxidation.  

This research aligns with the UN Ocean Decade Vision of ‘A Clean Ocean – Where sources of pollution are identified, reduced, or removed.’ Whilst sunscreens and UV filters are important for human health, their environmental fate and effects on marine life must be elucidated to accurately target which compounds are safer for use and which should be highlighted for regulatory approaches.   

Please note – this work is still ongoing, and results are still being collated. By the time of the congress in June 2025 – more results will be made available to share, particularly relating to the trophic-transfer potential to Mytilus galloprovincinalis.