**Abstract**

Rare earth elements are critical elements in the modern economy. Mining of rare earth elements has significantly intensified in the last several decades and studies of the environmental impact are in their infancy. In trace amounts, rare earth elements may support plant growth and development. At greater concentrations, rare earth elements are increasingly recognized as having a degree of mammalian toxicity; however, the mammalian toxicity potential may not be as acute as that for some heavy metals. The toxicity of rare earth elements requires detailed research to showcase toxicity thresholds for a wide range of ecosystem health. This study reveals case studies demonstrating that investigators rely on pollution indices, which do indicate that mining and ore processing possess environmental challenges. Further research has been identified to evaluate pollution indices for rare earth elements, especially concentrating on their biological availability.

**Keywords:** rare earth elements, pollution indices, mine contamination, human health impacts, environmental impact
