Due to their widespread use in high-tech products and processes, the rare earths and yttrium (REY) are nowadays considered as emerging microcontaminants in the environment. Accordingly, a good understanding of their biogeochemistry is highly relevant. Yet, the knowledge gap regarding the incorporation and fractionation of REY in biological and biogenic samples is still surprisingly large.
In contrast to marine and freshwater mollusc shells, only little has been published on REY in terrestrial mollusc shells. This is rather surprising as “Roman snails”, for example, are used for human consumption and considered a delicacy of the “French Cuisine”. The habitat of this land snail (Helix pomatia) extends over many countries in Europe. Its aragonitic shell precipitates from the snail’s mantle epithelium, implying that all REY incorporated into the shell must have been bioavailable to the organism.
We will present complete REY data for Helix pomatia shells from locations with different lithologies from several European countries. The shale-normalised REY (REYSN) patterns of all shells show a light and/or middle REY enrichment relative to heavy REY. Furthermore, most samples show small positive LaSN, pronounced negative CeSN and slightly positive YSN anomalies. We will discuss these features and compare the REYSN patterns with data of ambient substrate (rock or soil), plant samples and Cepaea snails, which are among the most widespread snails in Europe.