Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The available information on bioaccumulation of zirconium in the aquatic and terrestrial food chain was studied in algae and higher terrestrial plants, respectively, yielding the following conclusions:

- Although no data are available on other aquatic organisms besides algae and cyanobacteria, it can be concluded that zirconium has no potential to bioconcentrate/bioaccumulate in the aquatic food chain. A rapid uptake of zirconium from the medium was observed as well as a rapid desorption. The BCF values obtained for cyanobacteria and microalgae were very low, the highest value being 0.064 L/kg ww.

- Based on a study on the transfer of zirconium from soil to plants, it could further be concluded that there is no potential for bioaccumulation of zirconium in the terrestrial food chain, as all BSAF values were well below 1.

The available information on bioaccumulation of yttrium in the aquatic and terrestrial food chain yielded the following conclusions:

- BCF/BAF values for aquatic plants, aquatic invertebrates and fish were 992.7, 27.36 to 1482.6 and 1.3 to 54 L/kg ww, respectively. As for other rare earth elements, bioaccumulation seems to become less substantial when ascending the food chain, indicating no potential for biomagnification (as confirmed by data from a microcosm study). A key BAF value of 4.65 L/kg ww was calculated for fish. Based on the available data, the potential of yttrium for bioconcentration/bioaccumulation is concluded to be very low.

- Based on information from review publications on rare earth elements in terrestrial plants, it can be concluded that there is no potential for bioaccumulation of yttrium in the terrestrial food chain, as all reported BSAF values were well below 1.

Because based on the low water solubility of yttrium zirconium oxide, the release of yttrium and zirconium in the environment, and hence their bioavailability, is expected to be very limited, it can be concluded - taking into account the available data on bioaccumulation in aquatic and terrestrial organisms - that no bioaccumulation of yttrium or zirconium from yttrium zirconium oxide is to be expected in the terrestrial environment and only limited bioaccumulation may occur in the aquatic environment, levelling out when ascending the food chain.

Categories Display