Environmental Behaviour and Ecological Risk Assessment of Physical and Chemical Sunscreen Ingredients

Sunscreen ingredients are typical aquatic contaminants of emerging concerns (CECs), with physical (TiO 2/ZnO nanoparticles) and chemical (organic UV filters) types differing in environmental behaviors, yet systematic comparative studies are lacking. This paper systematically reviews relevant studies from 2006 to 2026, comparing their environmental occurrence, fate and ecotoxicity in aquatic ecosystems, and identifying key influencing factors and research gaps. Results show both types are widely detected globally (concentrations linked to anthropogenic activities), with physical nanoparticles tending to accumulate in sediments, whereas chemical filters exist in both dissolved and particulate forms in surface waters. They exhibit distinct fate characteristics and dose-dependent toxicity to aquatic organisms with different mechanisms, and chemical filters pose higher ecological risks in tourist coastal areas while cumulative risks of coexisting ingredients are common. Key research gaps include insufficient mixture toxicity studies, lab-field deviations and the lack of integrated risk assessment systems. This study enriches the knowledge of sunscreen- derived CECs, provides theoretical support for aquatic environmental management and eco-friendly sunscreen development, and proposes priorities for future research on mixture toxicity, lab-field validation and comprehensive risk assessment.