Thermal Water-Supplied Swimming Pools: A Scoping Review of Regulatory Frameworks, Disinfection Challenges, and Emerging Contaminants

Thermal water-supplied swimming pools are increasingly used worldwide for recreation, wellness, and therapeutic purposes, yet their management poses specific challenges due to the complex physicochemical properties of thermal and mineral waters and the need to balance microbiological safety with preservation of their natural characteristics. This scoping review adopts an integrative and comparative methodological approach, combining a systematic mapping of the scientific literature with a structured analysis of regulatory documents across 39 countries. It maps and comparatively synthesizes current evidence on health benefits, safety issues, and regulatory frameworks governing thermal pools. The analysis focuses on microbiological hazards and chemical risks related to disinfection practices, including the formation of disinfection by-products (DBPs). The review also examines emerging contaminants (CECs), including pharmaceuticals and personal care products (PPCPs), and discusses the potential role of thermal water environments in the development and spread of antimicrobial resistance (AMR). Moving beyond a purely descriptive approach, the analysis introduces a comparative framework that identifies distinct regulatory models and evaluates their implications for risk management and disinfection strategies. Thermal pools are conceptualized as integrated exposure systems generating complex mixtures with uncertain toxicological effects. The analysis reveals global regulatory heterogeneity and critical gaps in managing DBPs, CECs, and AMR-related risks, highlighting the need for integrated, risk-based and harmonized approaches within a One Health framework.