ASSESSING THE ECOTOXICOLOGICAL RISKS OF EMERGING CONTAMINANTS IN AQUATIC ECOSYSTEMS: A MULTISCALE APPROACH TO ENVIRONMENTAL TOXICOLOGY

Abstract

Emerging contaminants (ECs) have garnered increasing scientific and regulatory attention due to their widespread occurrence in aquatic ecosystems and their potential risks to environmental and public health. These unregulated compounds—such as pharmaceuticals, personal care products, endocrine disruptors, industrial chemicals, and microplastics—are often resistant to conventional wastewater treatment and have been detected in surface waters worldwide. Understanding their ecotoxicological impact is essential for safeguarding ecosystem integrity and human well-being.This study employed a multiscale methodological framework combining environmental sampling, molecular biomarker analysis, bioassays, and computational risk quantification to evaluate the impact of ECs in aquatic environments. Bioaccumulation, oxidative stress pathways, endocrine disruption, and biomagnification were examined in representative aquatic organisms, while cellular damage to enzymes, DNA, and membranes was assessed to understand mechanistic toxicity. A combination of analytical chemistry, ecological surveys, and risk modeling enabled the assessment of contaminant transfer through trophic levels and their long-term implications for ecosystem services.The results revealed a high frequency of bioaccumulative contaminants such as PFAS, heavy metals, and pharmaceuticals across sampled sites. Aquatic species demonstrated reproductive abnormalities, growth retardation, and disrupted population structures, while oxidative biomarkers confirmed chronic stress responses. Biomagnification trends were evident in predator species, and statistical models highlighted significant links between contaminant concentration and trophic level. Moreover, ecosystem-level effects included altered nutrient cycling, suppressed primary production, and biodiversity loss in impacted zones.This research underscores the urgent need for integrated monitoring systems and updated regulatory policies addressing emerging contaminants. The findings highlight the vulnerability of aquatic food webs to chemical stressors and support the development of predictive frameworks and mitigation strategies. Ultimately, the study advocates for a precautionary, science-informed approach to ensure the ecological sustainability and public health safety of global water systems.