Multi-media Occurrence, Risk Assessment, and Island-Specific Management Implications of Emerging Contaminants on Hainan Island, China

Emerging contaminants (ECs) pose increasing ecological risks in tropical environments due to intense anthropogenic inputs and climate-enhanced mobility. However, knowledge regarding EC occurrence and ecological risks in tropical island systems remains limited. Here, we present a meta-analysis of ECs in multi-media in Hainan Island, China, integrating data from 2661 samples across 12 environmental matrices, including atmospheric, aquatic, and solid-phase compartments. Across all compartments, 249 ECs were identified of which 27 were classified as priority substances with high ecological risk quotients (RQ>1). Concentrations varied widely across environmental media, with several contaminants reaching levels on the order of 10 4 ng L -1 in aquatic systems. EC occurrence exhibited high spatial heterogeneity, and three risk hotspots were identified: (i) a northern urbanized region influenced by wastewater discharge, (ii) an eastern agricultural belt characterized by mixed pesticide and antibiotic inputs, and (iii) a southern coastal tourism zone associated with elevated UV-filter contamination. Building on these findings, we propose a tiered, island-specific governance framework that integrates priority substance monitoring, tropical ecosystem-relevant risk thresholds, and phased source-control measures. By linking cross-media evidence with risk-based management, this study bridges the gap between fragmented monitoring data and targeted policy action, providing a scientific foundation for emerging contaminant governace in rapidly developing tropical island systems worldwide. • A total of 249 emerging contaminants across 12 environmental media were identified in Hainan Island. • Antibiotics, pesticides, endocrine-disrupting chemicals, and UV filters dominated multi-media occurrence profiles. • Coastal zones exhibited high UV-filter levels driven by tourism, posing risks to coral ecosystems. • Agricultural regions showed persistent pesticide accumulation in soils and sediments. • Twenty-seven high-risk substances and three spatial hotspots were identified, providing targeted guidance for pollution control.