scholarly journals How Rare Are Rare-Earth Elements in Living Things?

2021 ◽  
Vol 8 ◽  
Author(s):  
Rocío Bustillos-Cristales ◽  
Yagul Pedraza-Pérez ◽  
Luis Ernesto Fuentes-Ramírez

Rare-earth elements (REEs) are a group of metallic chemical elements that share some properties and that despite their name are not too rare in the Earth’s crust. Until recently, we did not know of any REEs that were necessary for any living organism. Now we know that there are some bacteria that use REEs to perform reactions that let them consume alcohol. Humans are also interested in REEs because these elements are valuable for many technological applications. In this article, we will explain the only known participation of REEs in living organisms and explain why future research on REEs is important.

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1663
Author(s):  
Nemi Malhotra ◽  
Hua-Shu Hsu ◽  
Sung-Tzu Liang ◽  
Marri Jmelou M. Roldan ◽  
Jiann-Shing Lee ◽  
...  

Rare earth elements (REEs) or “technology metals” were coined by the U.S. Department of Energy, a group of seventeen elements found in the Earth’s crust. These chemical elements are vital and irreplaceable to the world of technology owing to their unique physical, chemical, and light-emitting properties, all of which are beneficial in modern healthcare, telecommunication, and defense. Rare earth elements are relatively abundant in Earth’s crust, with critical qualities to the device performance. The reuse and recycling of rare earth elements through different technologies can minimize impacts on the environment; however, there is insufficient data about their biological, bioaccumulation, and health effects. The increasing usage of rare earth elements has raised concern about environmental toxicity, which may further cause harmful effects on human health. The study aims to review the toxicity analysis of these rare earth elements concerning aquatic biota, considering it to be the sensitive indicator of the environment. Based on the limited reports of REE effects, the review highlights the need for more detailed studies on the hormetic effects of REEs. Aquatic biota is a cheap, robust, and efficient platform to study REEs’ toxicity, mobility of REEs, and biomagnification in water bodies. REEs’ diverse effects on aquatic life forms have been observed due to the lack of safety limits and extensive use in the various sectors. In accordance with the available data, we have put in efforts to compile all the relevant research results in this paper related to the topic “toxicity effect of REEs on aquatic life”.


2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Thi Kim Dung NHU ◽  
Van Luan PHAM ◽  
Thi Chinh VU ◽  
Van Duoc TRAN

Rare earth metals are used in electricity, electronics, nuclear, optics, space, metallurgy,superconducting and super magnetic materials, glass and ceramics, and agriculture. Some rare earthelements are added to fertilizers for crops and some trials for animal feed. Rare earth elements, exceptfor radioactive promethium, are relatively abundant in the earth's crust. Vietnam has a tremendous rareearth potential, distributed mainly in the Northwest, including Nam Xe, Dong Pao, Muong Hum, andYen Bai. There are many research projects on rare earth ores of different types globally, but the focus ismainly on the essential minerals, including monazite, xenotime, and bastnaesite. This report summarizesresearch data on rare earth ore intending to produce a general assessment of rare earth ore and itsbeneficiation technology in Vietnam.


2021 ◽  
Vol 51 (3) ◽  
pp. 5-14
Author(s):  
N. V. Semendyaeva ◽  
A. A. Morozova ◽  
N. I. Dobrotvorskaya ◽  
N. V. Elizarov

The total content of rare earth elements in the soil profile of saline agricultural landscapes catena of the Baraba plain within Novosibirsk region was studied. The total content of zirconium, yttrium, scandium, gallium, including lanthanides - cerium, lanthanum and ytterbium was determined. Rare earth elements are extremely poorly analyzed. At present, their influence on plants, organisms of animals and humans is being actively studied, although the maximum permissible and tentatively permissible concentrations for them have not yet been developed. The total content of rare earth elements, determined in the soils of the catena, depends on the granulometric composition and the degree of humus content of the soil horizons. It was revealed that in the studied soils they are mainly contained in the number of clarkes of the earth's crust, with the exception of lanthanum in the humus horizons, where its content is almost 1.5 times (44-48 mg/kg) higher than the clarke in the earth's crust (29 mg/kg), and ytterbium (10 times higher than the clarke). Along the soil profile, an insignificant movement of rare earth elements in both vertical and horizontal directions was noted, which indicates a low mobility of their compounds. Zirconium predominates in the profile of the studied soils from the group of rare earth elements. Its content in the humus horizons of soils of eluvial positions is within the clarke of the earth's crust; variations along the profile are insignificant. Ytterbium is contained in large quantities - from 1.89 to 4.05 mg/kg of soil, which is significantly higher than the clarke of the earth's crust (0.3 mg/kg of soil). The role of lanthanides in the soil -plant - animal - human system requires further in-depth study.


1965 ◽  
Vol S7-VII (1) ◽  
pp. 187-194
Author(s):  
Georges Machairas

Abstract The rocks of the earth's crust and upper mantle belong to three categories. The first includes those rocks that have achieved complete equilibrium. Rocks of the second category represent transitory equilibrium, their formation varying relative to the chemical elements available and the physical and dynamic conditions. Rocks of the third category consist of limestones, shales, and other detrital sediments. Their composition is completely controlled by that of the source rock. The global discontinuities including that at the surface, and the Mohorovicic and Lehmann-Gutenberg discontinuities are briefly discussed in terms of differences in densities of rocks of the various categories.


Author(s):  
Mikhail M. Labushev ◽  
◽  
Timofey M. Labushev ◽  

The topicality of the research comes from the need to obtain new knowledge about the manifestation of the periodic law in nature. Research aim is to associate the periodic system of chemical elements with the chemical composition and structure of natural objects. The research method suggests the creation of a solid model of the periodic system of chemical elements along with its comparison with ore formation objects as well as the manifestation of chemical elements isomorphism and some natural processes geochemistry. Research results. The solid version of the periodic table of the first 95 chemical elements together with a conventional zero element is proposed. Each volume cell characterizes a chemical element with an elementary crystal lattice of simple substance. Similar models can be composed of minerals and rocks associating with material substance of the earth's crust. 16 vertical groups in the model are arranged in a snake-like pattern. The model of the earth's crust with the “cubes” of chemical elements, minerals and mineral associations is proposed. The elements of adjacent spatial groups are naturally concentrated in combination, showing isomorphism while minerals enter the crystal lattice. The relative position of adjacent “cubes” follows the rule of translation in mutually perpendicular directions. The chemical elements of the first group can correspond spatially to volcanoes as well as mud volcanoes. The place of the zero chemical element is considered to be occupied by the elements of adjacent spatial groups. It is assumed that the faces of the “cube” of chemical elements are permeable areas through which chemical elements can be transferred. Summary. The confirmation of the model follows while considering ore formations, isomorphism of chemical elements in minerals and geochemistry of volcanic processes. 46 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 1. 2020 ISSN 0536-1028 Key words: chemical elements; solid model of periodic system; ore formations; isomorphism in crystals; geochemistry of volcanic processes.


2021 ◽  
Vol 27 (1) ◽  
pp. 15-23
Author(s):  
Т. Tsyrenov ◽  

The purpose of the study is to investigate rare-earth elements distribution features in all components of the natural-technogenic complexes of Akatuevsky, Blagodatsky and Novo-Shirokinsky polymetallic deposits of Eastern Transbaikalia. Due to increasing demand for rare-earth elements (REE) in various fields of industry, identification of features of REE distribution in natural-technogenic complexes of polymetallic deposits of Eastern Transbaikalia is relevant. The chemical elements of the REE group include 15 elements, yttrium (Y) and the lanthanoid group consisting of 14 elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu). Determination of the elemental composition of samples was carried out by X-ray fluorescence method in the Geological Institute of the Geological Institute of the Siberian Branch of the Russian Academy of Sciences (Ulan-Ude) and by ICP- MS method in the laboratory of SGS Vostok Limited (Chita). In the process of investigations REE concentrations in all components of natural-technogenic complexes of Akatuevsky, Blagodatsky and Novo-Shirokinsky polymetallic deposits (lead-zinc ores, technozems, soils) were determined. Their regular decrease of REE concentrations in the order: soils→technozems→lead-zinc ores was established. In the most of studied samples there is a decrease of heavy lanthanides content relative to light ones, as well as negative europium anomaly, in some samples of lead-zinc ores positive europium anomaly is observed. Europium anomaly magnitude (Eu/Eu*) is an indicator of the degree of differentiation of magmatic melts, determined by plagioclase fractionation processes. It is known that feldspars serve as the main controller of the Europium anomaly. The phenomenon of a negative europium anomaly is observed if plagioclase remains in the source after fractional crystallization or partial melting. Positive europium anomaly in sulphide ores is caused by the presence of barite, as well as by the accumulation of plagioclase in the liquid phase due to the fractionation process. REE is known to have adverse effects on the environment due to its high biological and biochemical activity. Modern methods of remediation of the potential damage to the environment have been proposed


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