Highlights

• Researchers expose severe environmental risks from rare earth element waste.
• Contamination occurs in water, soil, and food chains due to rare earth element waste.
• Current waste disposal methods are inadequate, leading to potential human health impacts such as oxidative stress and DNA damage.
• Low recycling rates and inefficient recovery processes pose significant challenges for managing rare earth element pollution.

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A new review led by Zhunan Xiong and Tao Liang of the Chinese Academy of Sciences (Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research (opens in a new tab)) and published in the Journal of Cleaner Production offers a sweeping and sobering assessment of the environmental and health impacts of rare earth element (REE)-containing waste. The study—titled “A review of rare earth elements in waste disposal: Release mechanisms, environmental behaviors and risks”—explores the mechanisms by which REEs escape into the environment, the risks posed by their improper disposal, and the gaps in global monitoring and recycling infrastructure.

The Central Hypothesis

Xiong and colleagues hypothesize that existing waste disposal and recycling methods inadequately control the environmental release of REEs, especially from industrial, medical, electronic (e-waste), and municipal solid waste (MSW) streams. This uncontrolled release leads to ecotoxicological harm, long-term bioaccumulation, and increased human exposure, particularly in vulnerable communities.

Key Findings

The authors provide a systematic review of release pathways, including landfill leachate, incineration ash, and atmospheric dispersion from informal e-waste recycling. Standout observations include:

• Gadolinium anomalies—traced to gadolinium-based contrast agents (GBCAs) in medical imaging—have been found in groundwater and even drinking water, signaling persistence and mobility.
• Incineration and e-waste dismantling raise REE levels in soils and airborne particulates, with heightened exposure risks for workers.
• Bioaccumulation of REEs has been documented in aquatic organisms, plants, and algae—posing a food chain risk and potential for long-term human health impacts.
• Health effects in exposed populations include oxidative stress, DNA damage, endocrine disruption, and anemia—especially among e-waste workers.

The study warns that despite growing demand for REEs in green technologies, disposal practices remain in the industrial dark ages. Existing recovery processes are inefficient, and recycling rates are abysmally low, especially for heavy REEs such as dysprosium and terbium.

Limitations

The authors acknowledge a lack of uniform methodologies for measuring REE bioavailability and toxicity across different ecosystems. Epidemiological data on long-term human exposure are still sparse, and the environmental fate of many REEs remains poorly characterized, especially under varied geochemical conditions.

Implications

This review conveys a clear message: rare earths, while vital to modern technology, pose growing environmental and health hazards when mishandled at the end of their life cycle. As nations rush to secure REE supply chains, the downstream risks of REE pollution and bioaccumulation require urgent attention from regulators, technologists, and scientists.

For investors and policymakers, the findings reinforce the case for advancing REE recycling innovation and stricter oversight of waste treatment. The cost of inaction won’t just be environmental—it likely will be geopolitical, public health, and reputational.

Citation: Xiong, Z., Li, S., Wang, S., Wang, J., Wang, L., & Liang, T. (2025). A review of rare earth elements in waste disposal: Release mechanisms, environmental behaviors, and risks. Journal of Cleaner Production, 521, 146239. https://doi.org/10.1016/j.jclepro.2025.146239 (opens in a new tab)