Abstract

Nanotechnology offers innovative solutions to environmental challenges, including wastewater treatment and industrial waste management. However, the widespread discharge of municipal sewage, industrial solvents, agrochemicals, heavy metals, and nanoparticles threatens aquatic ecosystems. While nanomaterials hold promise for pollution remediation, their high surface reactivity and small size facilitate biotransformation, increasing their environmental interactions and disrupting aquatic food webs, particularly in tropical and subtropical regions. This review examines the adverse effects of engineered nanoparticles (ENPs) on aquatic life, emphasizing their bioaccumulation in species. Titanium dioxide nanoparticles exhibit bioaccumulation rates of up to 86%, whereas copper nanoparticles accumulate at only 0.9 ppb. Affected organs include the gills, brain, and lungs, highlighting nanoparticle contamination's widespread impact. Biofilms enhance nanoparticle adsorption and pollutant transport. This study introduces the bioaccumulation index (BAI), improving bioaccumulation assessment over conventional methods. Findings stress the need for regulatory frameworks, sustainable nanotechnology, and advanced monitoring to reduce environmental risks. Future work should focus on long-term toxicity studies, eco-friendly designs, and mitigation strategies. Integrating bioaccumulation models and risk assessment tools can help balance technological progress with aquatic ecosystem sustainability, promoting responsible nanotechnology for a cleaner future.