Abstract
The anthropogenic part of the rare earth elements (REE) cycle is becoming increasingly noticeable due to its increasing mining, using, accumulating in wastes. The aim of the work is to summarize current scientific data of the REE effect on living organisms in different habitats, including the mechanisms and specificity of their action, as well as bioaccumulation. Both REE’s natural geochemical anomalies and anthropogenic polluted zones are known. The REE soil accumulation in industrial areas is up to 2.3 µg/kg; in urban snow the REE content varies from 0.411 µg/kg to 1.463 µg/kg. The REE negative molecular mechanism provokes oxidative stress; the latter can be expressed as stimulation of vital functions at low doses of toxicants, and as inhibition of organisms with increasing concentrations. The REE toxic concentrations depends on the chemical element nature, as well as on set of environmental factors and the exposure target, but they are often 2–3 orders of magnitude higher than those of heavy metals. In the early 21th century, this served as a basis to consider REEs environmentally safety. But many sublethal and delayed effects of REEs including endocrine disorders and negative effects on the breeding potential of populations have now been shown. The complexity of REEs study is due to additive, antagonistic, or synergistic effects of their mixtures and combinations with other elements. Thus, a comprehensive study of rare earth elements remains an urgent task with preventive environmental importance. The vulnerable species identification, REEs delayed effects and the REEs co-action with other substances are the most promising scientific issues.