Emerging and traditional contaminants in water resources: a review from the perspective of the American continent

The presence of emerging contaminants (ECs), associated with the widespread use of pharmaceuticals, personal care products, illicit drugs, microplastics, and other compounds derived from modern consumption, constitutes a growing environmental threat. Their continuous entry through wastewater and inefficient treatment systems generates endocrine disruptions, reproductive effects on wildlife, and potential risks to human health. In contrast, traditional contaminants (TPs), such as heavy metals, have been more studied and partially regulated, although their toxicity persists as a challenge for water quality and public health. Therefore, systematic monitoring of ECs and TPs is essential to identify sources of contamination, assess impacts, and guide remediation and environmental management strategies. The objective of this systematic review was to compile and analyze scientific literature on the incidence and effects of ECs and TPs in water resources, focusing on their most common types, environmental pathways, and biological models used for toxicity testing. The review was based on 200 research articles from the Americas. The search was conducted in ScienceDirect, Web of Science, PubMed, and Scopus®. databases, using combinations of keywords related to etiologies, TPs, and their presence in water resources. The inclusion criteria considered only publications in English, published between 2005 and 2024. Studies from other regions, articles outside the time range, and duplicates were excluded, and only one version of each work was retained. The final selection was made by reviewing titles, abstracts, and references, allowing for independent extraction of relevant information. The findings provide a fundamental framework for improving water resource management and underscore the urgent need to integrate etiologies into regulation and monitoring programs to ensure the sustainability of aquatic ecosystems.