Trihalomethanes in Latin American drinking water: Analysis of regulations, reported levels and advances in quantification methods

Abstract

Trihalomethanes (THMs) in drinking water are a growing concern in Latin America due to their health risks and regulatory inconsistencies. This study examines existing regulations, detected levels, and analytical methodologies used across the region through a combined approach that includes bibliometric analysis, a systematic review of scientific literature, and a regulatory analysis. A comprehensive search of Web of Science and Scopus, using the search equation: "trihalomethanes" AND "water" AND "drinking," identified 73 relevant articles published between 2000 and 2024. The regulatory frameworks of all Latin American countries were analyzed. The study categorized countries based on their regulatory frameworks, compiled reported THM concentrations, and assessed advancements in analytical methodologies. The results reveal a pronounced regional disparity: while countries like Brazil, Colombia, Mexico, and Chile have developed regulatory frameworks and extensive research, other nations lack both regulations and studies entirely. The detected levels of THMs show significant variability, and in some cases, they far exceed the limits recommended by the World Health Organization (WHO), notably Brazil, with concentrations as high as 4220 µg/L. Analytical methodologies have evolved toward more efficient and environmentally sustainable techniques, such as headspace solid-phase microextraction (HS-SPME) and hollow fiber solvent bar microextraction (HF-SBME), enabling more precise detection in the ng/L to µg/L range. Effective strategies for controlling THMs were identified, including optimizing disinfection processes, removing precursors through nanofiltration and activated carbon, and using alternative disinfectants. The study highlights the urgent need for harmonized regulations, systematic monitoring, and increased research efforts to address knowledge gaps in THM contamination in drinking water across Latin America. The findings underscore the importance of implementing national and regional monitoring programs, developing evidence-based regulatory frameworks, and promoting research in underrepresented countries to ensure safe drinking water and mitigate public health risks.