Toxicity of rare earth elements: An overview on human health impact

Rare earth elements (REEs) are metals including the 15 lanthanides together with Yttrium and Scandium. China is the leading country in their exploitation and production (~90%). REEs are necessary for the production of several technological devices. This extended use of REEs has raised concerns about human health safety. In this review, we investigated the hazard of REEs to human health and the main gaps into the knowledge like as the need to develop further focused research activity. We categorized the research papers collected into eight main sections: environmental exposure, association of REEs with health problems, exposure to REEs due to lifestyle, REE exposure through the food chain, Gd contrast agents causing health problems, occupational REE exposure, and cytotoxicity studies of REEs. This review provided information about the exposome of REEs (the exposure of REEs to the human body), the existing research data, and the gaps that require attention and must be further investigated. More than one third of the literature about REE toxicity to human health concerns their cytotoxicity to human cell lines, while hair, blood serum and blood are the most studied matrices. The main results evidenced that REEs can enter human body via several routes, are associated with numerous diseases, can cause ROS production, DNA damage and cell death, and are more toxic to cancer cells than normal cells

Comparative study of two methods for rare earth elements analysis in human urine samples using inductively coupled plasma-mass spectrometry

The application of rare earth elements (REEs) in several areas, including hightech technology, agriculture, medicine, and fuels, has made them an essential component of our everyday life. This extensive use of REEs in several technologies is expected to potentially impact human health. Even if several studies investigated the levels of REEs in human matrices, until now no standard method has been established for analyzing these elements in human matrices. The sample analysis should be of high quality, and the methods should be validated properly to ensure the quality of the procedure and traceability of the analytical data. In this research, we compared the validation and effectiveness of two different methods of sample preparation for human urine samples: a simple dilution of the sample (DIL) was compared with microwave assisted-acid decomposition (MIN) for tracing REE levels in human urine samples. The analysis was carried out by inductively coupled plasma mass spectrometry (ICP-MS). The working conditions have been set in high-sensitivity mode. Accuracy of the proposed method was evaluated by spiking the sample matrix with known concentrations of analyte standards. Both methods showed adequate precision of repeatability and intra-laboratory reproducibility, with the DIL method showing better precision of both repeatability and reproducibility than the MIN method. The CVr% values of repeatability range from 1.5 to 12% for the DIL and from 8.4 to 16% for the MIN method. The CVr% values of reproducibility range from 6.2–23% for the DIL and from 8.6 to 24% for the MIN method. REE recoveries for both methods were very close to 100%. Both methods proved to be effective for the determination of REE levels in human urine matrices

A first attempt to evaluate the toxicity to Phaeodactylum tricornutum Bohlin exposed to rare earth elements

The increasing use and demand of rare earth elements in many emerging technologies is leading to a potentially higher input to the marine environment. This study compared for the first time the effect of lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), and erbium (Er) to the microalga Phaeodactylum tricornutum Bohlin. The algal growth inhibition was investigated after 72 h of exposure. The median effect concentrations (EC50) ranged from 0.98 mg/L to 13.21 mg/L and elements were ranked as follows: Gd > Ce > Er > La > Eu > Nd > Dy > Sm. The comparison of predicted no effect concentrations (PNEC) for hazard and risk assessment with measured environmental concentrations showed that ecological risks deriving from REEs could be present, but limited to specific environments like estuarine waters. The results support evidence of actions to manage the REE impact in seawater environments, looking to improve the monitoring tailored to the different and dynamic nature of ecosystems

Hormetic Effects of Cerium, Lanthanum and Their Combination at Sub-micromolar Concentrations in Sea Urchin Sperm

Rare earth elements (REEs) cerium (Ce) and lanthanum (La) and their combination were tested across a concentration range, from toxic (10(-4) to 10(-5) M) to lower concentrations (10(-6) to 10(-8) M) for their effects on sea urchin (Sphaerechinus granularis) sperm. A significantly decreased fertilization rate (FR) was found for sperm exposed to 10(-5) M Ce, La and their combination, opposed to a significant increase of FR following 10(-7) and 10(-8) M REE sperm exposure. The offspring of REE-exposed sperm showed significantly increased developmental defects following sperm exposure to 10(-5) M REEs vs. untreated controls, while exposure to 10(-7) and 10(-8) M REEs resulted in significantly decreased rates of developmental defects. Both of observed effects-on sperm fertilization success and on offspring quality-were closely exerted by Ce or La or their combination.Open access funding provided by Universita degli Studi di Napoli Federico II within the CRUI-CARE Agreement.Universita degli Studi di Napoli Federico II within the CRUI-CARE Agreemen

Levels of rare earth elements on three abandoned mining sites of bauxite in southern Italy: A comparison between TXRF and ICP-MS

The essential utilization of rare earth elements (REEs) for the production of several electronic devices is making the demand for them being increased all the time. This extensive use of these elements has also increased concern about human and environmental health. Previous studies have shown that REE levels are higher in environmental samples near mining sites, and they are highly possible to be transferred to biota. In this study, REE levels were determined in environmental samples collected from three abandoned mining sites of bauxite (Gargano, Otranto, and Spinazzola) in the region of Puglia, Southern Italy. The samples were digested and analyzed by two different techniques, Total X-Ray Fluorescence (TXRF) and Inductively Coupled Plasma – Mass Spectroscopy (ICP-MS) to investigate which technique is the most suitable for analysis of the REE content in samples from abandoned mining sites of bauxite. Only 6 REEs could be detected by TXRF, while all REEs were detected in all the samples by ICP-MS. Spinazzola is the richest site and Ce the most abundant REE in all three regions. REE levels are correlated between the soil and biota samples in many cases, although the calculation of the bioconcentration factor showed that REEs are not bioaccumulative. ICP-MS seems to be a more suitable technique for analysis of the whole REE content in environmental samples from abandoned mining sites of bauxi