The article reviews the toxic effects of rare earth elements (REEs) on human health, highlighting the significant environmental pollution and health risks associated with their long-term, large-scale mining and utilization. REEs, including lanthanides, Sc, and Y, are essential metals in modern technology but pose serious health threats due to their accumulation in the environment and human body. The review covers various exposure routes such as inhalation, ingestion, and dermal contact, which lead to the deposition of REEs in different organs and systems, causing multifaceted health issues. Key findings include: 1. **Respiratory System**: REEs can cause lung damage, including inflammation, granulomatous degeneration, pulmonary fibrosis, and even cancer, through oxidative stress and pulmonary inflammation. 2. **Nervous System**: REEs can cross the blood-brain barrier, leading to neurological diseases, neurodegeneration, and neurosis. They can also affect fetal brain development and cause reproductive toxicity. 3. **Cardiovascular System**: REEs can reduce blood cell counts, induce inflammatory responses, and damage endothelial cells, contributing to hematopoietic disorders and vascular injuries. 4. **Reproductive System**: REEs can impair spermatogenesis, reduce sperm quality, and cause testicular tissue damage. They can also affect fetal and neonatal outcomes, including cleft lip and palate, and increase the risk of spontaneous abortion. 5. **Other Systems**: REEs can reduce bone density, interfere with bone metabolism, and cause gastrointestinal and renal injuries. The review also discusses the mechanisms of REE toxicity, including genetic damage, epigenetic changes, and alterations in signaling pathways. Despite the extensive research, there are still gaps in understanding the specific mechanisms and critical standards for human health hazards. The authors emphasize the need for further epidemiological studies, the establishment of safety thresholds, and the development of diagnostic and therapeutic measures to address REE-related diseases.The article reviews the toxic effects of rare earth elements (REEs) on human health, highlighting the significant environmental pollution and health risks associated with their long-term, large-scale mining and utilization. REEs, including lanthanides, Sc, and Y, are essential metals in modern technology but pose serious health threats due to their accumulation in the environment and human body. The review covers various exposure routes such as inhalation, ingestion, and dermal contact, which lead to the deposition of REEs in different organs and systems, causing multifaceted health issues. Key findings include: 1. **Respiratory System**: REEs can cause lung damage, including inflammation, granulomatous degeneration, pulmonary fibrosis, and even cancer, through oxidative stress and pulmonary inflammation. 2. **Nervous System**: REEs can cross the blood-brain barrier, leading to neurological diseases, neurodegeneration, and neurosis. They can also affect fetal brain development and cause reproductive toxicity. 3. **Cardiovascular System**: REEs can reduce blood cell counts, induce inflammatory responses, and damage endothelial cells, contributing to hematopoietic disorders and vascular injuries. 4. **Reproductive System**: REEs can impair spermatogenesis, reduce sperm quality, and cause testicular tissue damage. They can also affect fetal and neonatal outcomes, including cleft lip and palate, and increase the risk of spontaneous abortion. 5. **Other Systems**: REEs can reduce bone density, interfere with bone metabolism, and cause gastrointestinal and renal injuries. The review also discusses the mechanisms of REE toxicity, including genetic damage, epigenetic changes, and alterations in signaling pathways. Despite the extensive research, there are still gaps in understanding the specific mechanisms and critical standards for human health hazards. The authors emphasize the need for further epidemiological studies, the establishment of safety thresholds, and the development of diagnostic and therapeutic measures to address REE-related diseases.