Ecotoxicological Risks of Waterborne Emerging Contaminants to Aquatic Organisms: An Integrative Literature Review

Purpose: Emerging contaminants are released into the environment through diverse pathways, ranging from hospital activities and pharmaceutical manufacturing to animal welfare practices, aquaculture, criminal activities, and public events, thereby increasing their prevalence. This situation poses a serious environmental risk for organisms inhabiting aquatic ecosystems. This review aims to systematically synthesize current knowledge on the molecular and physiological effects of emerging contaminants on aquatic organisms. Methods: Aligned with the purpose of the study, PubMed, Web of Science (WOS), and Google Scholar databases were searched for studies published between 2001 and 2021; these constitute the formal corpus for the integrative analysis. While the systematic synthesis and data visualizations are strictly based on this timeframe, selected post-2021 studies are included only as supplementary contextual evidence to discuss recent developments. A total of 425 articles were identified, of which 48 were examined through a structured screening and evaluation process based on subject content, keywords, and reference criteria. The search strategy employed combinations of predefined keywords—such as ‘emerging contaminants,’ ‘aquatic life,’ ‘aquatic organisms,’ ‘public health,’ ‘toxic effects,’ and ‘environmental exposure.'" Studies were included if they addressed ecotoxicological risks to aquatic organisms and excluded if they lacked relevance to these criteria. Results: According to the frequency analysis findings, it can be concluded that various types of emerging contaminants released into the environment induce multidimensional biological alterations in aquatic organisms. Of the 48 studies analyzed, 50% focused on freshwater, marine fish, and amphibians; 4.2% on aquatic invertebrates; and 45.8% on other organism groups. Among the contaminant categories, opioids were reported in 32% of cases, while synthetic compounds accounted for 28% in aquatic ecosystems. At the molecular level, these changes manifest as variations in gene expression, irregularities in protein synthesis, and disruptions in cellular signalling pathways. At the physiological level, metabolic impairments, behavioural modifications, and disturbances in homeostatic balance have been reported. These findings highlight that the presence of emerging contaminants in environmental water sources represents not only a chemical pollution issue but also a critical threat to ecosystem health, biodiversity, and sustainable environmental management. Conclusions: This study contributes by highlighting that, given the increasing environmental prevalence of newly emerging pollutants, the integration of toxicology, ecology, and environmental engineering is vital for reducing toxicological risks, protecting aquatic ecosystems, ensuring sustainable ecological balance, and safeguarding public health.