Distribution Patterns and Accumulation Factors of Rare Earth Elements in the Organism of Manchurian Wapiti and Wild Boar in Primorsky Krai, Russian Far East.

Abstract

This study presents a comparative analysis of rare earth element (REE) distribution in 24 organs and tissues of four Manchurian wapiti (Cervus canadensis xanthopygus) and four wild boar (Sus scrofa) harvested near the borders of five protected natural areas in Primorsky Krai, Russian Far East. A total of 192 biological samples (96 per species) were analyzed using ICP-MS. At the level of all analyzed organ and tissue samples, statistically significant interspecific differences (p = 0.004) were observed only for europium (Eu), with wapiti showing the most pronounced Eu anomaly in bone tissue (δEu = 190 compared to 52 in wild boar). Analysis of REE concentrations among individual organs and tissues revealed species-specific accumulation patterns: in Manchurian wapiti, REE are deposited primarily in hair and intestine, whereas in wild boar, the liver serves as an additional major depot alongside hair. Elevated concentrations of heavy REE were detected in wild boar lung tissue. The presence of REE in the central nervous system of both species suggests that these elements can reach neural tissues, raising questions about their potential neurotoxicity. These results indicate that interspecific differences in REE accumulation and distribution may be related to behavioral and physiological factors, including dietary habits, digestive system type, and species-specific target organs. This study provides data and potential insights for understanding REE behavior in the body of terrestrial mammals.