Organic ultraviolet filters (OUVF) in freshwater bathing areas: Necessary sunscreen protection versus environmental threat

This study presents the first comprehensive assessment of seven organic ultraviolet filters (OUVFs), namely benzophenone-3 (BP3), 4-methylbenzylidene camphor (4MBC), octocrylene (OC), ethylhexyl methoxycinnamate (EHMC), isoamyl p-methoxycinnamate (IAMC), butyl methoxydibenzoylmethane (BMDBM), and homosalate (HMS), in Polish freshwater ecosystems, providing novel insights into their seasonal variability and ecological risks. Water samples from three recreational lakes and a reference reservoir were collected in April and July from both surface and water column layers were analysed to quantify OUVFs concentrations and calculate aquatic risk quotients (RQs). Our results revealed a clear seasonal pattern, with significantly higher OUVF concentrations in July, particularly at Kryspinów reservoir, coinciding with peak tourist activity. IAMC, HMS, and BMDBM were the main contributors to moderate cumulative risk values with localized high-risk values at Kryspinów, while the reference site exhibited consistently low contamination and negligible risks. This study not only establishes a baseline for OUVF contamination in Central European recreational waters but also demonstrates the utility of a multi-depth sampling approach in assessing pollution dynamics. The findings contribute to the growing understanding of emerging contaminants in freshwater ecosystems and underline the need for enhanced environmental monitoring and regulatory measures.