Rare earth elements on aquatic organisms: Toxicity, detoxification, and ecological implications

Rare earth elements (REEs) are widely used in various industries, such as electronics, renewable energy, and manufacturing, leading to their gradual accumulation in ecosystems, including water environments. As emerging pollutants, REEs find their way into water bodies through various channels, such as industrial discharge, mining runoff, and sewage. Despite their growing presence, the understanding of their toxicity in aquatic organisms is limited, representing a significant gap in current research. This review studies the bioaccumulation and toxicity of REEs in aquatic organisms, highlighting factors such as water chemistry, speciation, and organism characteristics that influence their uptake and effects. REEs can induce oxidative stress, ion imbalance, enzyme inhibition, and reproductive toxicity in aquatic species, leading to potential impairments in growth, survival, and reproduction. The ecological consequences of REE contamination extend beyond individual species and potentially affect community structures, disrupt food webs, and alter ecosystem functioning. This review emphasizes the urgent need for international regulatory guidelines to manage REE pollution in aquatic environments to protect biodiversity and ecosystem health.