Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The extent to which bioaccumulation may occur depends on the bioavailability of lanthanum for uptake. Bioavailability is affected by the substance’s water solubility as well as by the characteristics of the receiving environmental compartment, determining lanthanum speciation. Because lanthanum speciation and bioavailability are expected to be similar after release of water soluble lanthanum compounds (e.g., lanthanum trinitrate, lanthanum trichloride and lanthanum acetate) to the environment, data from laboratory studies using any soluble lanthanum compounds were lumped for covering the endpoint. Similarly, data from field studies, in which lanthanum distribution between water and biota was studied, were added to the lumped dataset for covering the endpoint.

The available information on bioaccumulation of lanthanum in the aquatic and terrestrial foodchain was thoroughly studied, yielding the following conclusions:

- In the aquatic foodchain, lanthanum has clearly the potential to bioconcentrate/bioaccumulate in organisms from lower trophic levels, such as aquatic plants and invertebrates. However, the available information on fish, including valuable information from a microcosm experiment, indicate that bioaccumulation of lanthanum decreases when ascending the foodchain. The values obtained for fish were very low and indicate that lanthanum does certainly not biomagnify and has a limited potential for bioaccumulation at higher levels in the foodchain. There is evidence that lanthanum is essential for living organisms. As for many other metals (even non-essential metals), organisms are able to regulate metal uptake and retainment, and bioaccumulation is expected to be limited. Also, a concentration dependency may exist for bioaccumulation of lanthanum in aquatic organisms, showing increasing BCF/BAF values with decreasing environmental concentrations (down to background levels). Indeed, for several field studies in which lanthanum exposure was very low, quite high BCF/BAF values were observed for aquatic plants or invertebrates.

- Based on a selection of reviews on the transfer of lanthanum and other rare earths from soil to plants, it could further be concluded that there is no potential for bioaccumulation of lanthanum in the terrestrial foodchain, as all BSAF values were < 1. BSAF values for a sediment dwelling amphipod were also consistently below 1.