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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Lutetium oxalate is a poorly water soluble solid compound which may give rise to very small dissolved lutetium concentrations in water. Any dissolved lutetium will be subject to speciation, and because of the complexation behaviour of lutetium with environmentally relevant ligands such as phosphates, carbonates, etc. under environmentally relevant conditions, and the consequent precipitation of its complexes formed with these ligands, only very small concentrations of dissolved lutetium can be expected to occur in the aquatic environment.  Considering the organic part, i.e. oxalate, the acid residue of oxalic acid, is readily biodegradable.

The behaviour of lutetium oxalate in the environment is assessed following an elemental approach, i.e. with the focus on (dissolved) lutetium. It is clear that in this respect, hydrolysis resulting in abiotic degradation is not a relevant parameter for this compound. Similarly, biodegradation is not considered relevant for inorganic compounds.

Although lutetium oxalate is not expected to give rise to high levels of lutetium available for uptake by living organisms or available for adsorption to particulate matter, the information from such studies is considered relevant and informative of the environmental fate of any lutetium released from this compound in the environment. Therefore, the endpoints bioaccumulation and adsorption have been assessed in this dossier based on the literature data dealing with the lutetium element.

For aquatic bioaccumulation, a bibliographical review based on ca. 60 publications (1964-2016), containing information on the accumulation of lanthanides (including lutetium), yttrium and/or zirconium in aquatic organisms, was written to cover this endpoint. Based on the pool of evidence discussed in this review, the overall conclusion was drawn that lanthanides such as lutetium are unlikely to biomagnify in predatory organisms or humans exposed via the environment.

For adsorption, based on all available information, key log Kp values of 5.20, 5.11 and 3.72 L/kg were obtained for lutetium partitioning in suspended matter-water, sediment-water, and soil-water systems, respectively. The overall conclusion is that lutetium strongly adsorbs to particulate matter. As a result, partitioning to sediment and soil may be expected over time upon release to the aquatic environment.

Additional information