Content of Rare-Earth Elements in Soils of Technogeochemical Anomalies

This review presents geochemical and medical-ecological information on the content, distribution, and accumulation of rare-earth elements in soils of technogeochemical anomalies. The significance of V.I. Vernadskii’s ideas in development of the theory of the chemical elements atoms migration in the biosphere is demonstrated. Specific features of the atomic structure of rare-earth elements, determining their chemical and toxic properties, are presented. Natural mineral concentrators of scandium, ytterbium, and the lanthanide group are considered in detail. Distribution patterns for these chemical elements in mining deposits and soils of technogenic impact zones are analyzed. Characteristic reactions of rare-earth elements on the soil-formation process and their interaction with various soil compounds (fractionation, complexation) are presented. Characteristics of the Cherepovets technogeochemical anomaly, contaminated with barium, lanthanum, and cerium are given in more detail. The problem of soil profile contamination in tailings dumping sites is discussed. The issue of biological fixation of rare-earth elements by plants and main directions of their migration in the natural environment are discussed. It is shown that soils of urbanized territories are a depositing medium for such elements and carry a great environmental and technogenic burden. Data are provided concerning ways to reduce the toxic effects of rare-earth elements on the environment and measures to control soil pollution in order to prevent the occurrence of environmentally caused diseases in humans.