Dilanthanum tricarbonate

Bioaccumulation: aquatic / sediment

Description of key information

It is to be expected that bioaccumulation is low.

Additional information

No bioaccumulation studies are available for Lanthanum carbonate in fish and other biota.

According to “Guidance on information requirements and chemical safety assessment Appendix R.7.13-2: Environmental risk assessment for metals and metal compounds”, the determination for bioaccumulation potential of naturally occurring substances, such as metals, is more complex. Most available concepts and tools to assess the bioaccumulation are inadequate for the assessment of metals, since the methods were originally developed on limited results obtained for neutral lipophilic organic substances. The potential to bioaccumulate and/or to biomagnify of this substances is directly related to the inherent properties of the substances.

Lanthanum carbonate is a poorly soluble substance, which is considered to be abiotic stable under normal environmental condition (pH, temperature). A release of Lanthanum ions is to be expected in a relevant amount only at pH < 4, or bicarbonate if excess of carbon dioxide exists. At pH values above 6, Lanthanum carbonate may undergo hydrolysis, forming Lanthanum bicarbonate. The insoluble Lanthanum hydroxide increases with increasing pH value. However, release of Lanthanum ions under environmetal conditions is in principle negligible.

Several monitoring studies are available, in which the concentration of elementary Lanthanum in biota of different trophic levels, such as molluscs, worms, and crustaceans, but except fish, were investigated in these studies. In some monitoring studies, the authors compared the BCF estimated based on the monitoring data with the BCF derived on the basis of laboratory data measured in natural sediment, surface water and biota (crustaceans) as well. In addition, one study with mixed REE, amongst others the analogue substance Lanthanum trinitrate, in carp is available. The data were generated with soluble Lanthanum compounds, as well as the monitoring data, which are considered to be attributed to soluble Lanthanum compounds.

Short overview of available data:

Sun et al. (1996), carp: BCF for muscle, skeleton , gills and internal organs were 0.5 — 1.27, 0.44 — 3.66, 3.86 — 13.8 and 45.2 — 828, respectively.

Sneller et al. (2000), bivalves, worms, crustaceans: BCF is 15000 – 50000, 8000 - 120000 and 10000 – 40000, respectively

Sneller et al. (2000), Corophium volutator: BCF(lab, pore water) = 22387, BCF(lab, surface water) = 107152, BCF(field) = 228840

Snellet et al. (2000), Corophium volutator: BSAF = 2.57

Moermond et al. (2001), Corophium volutator: BSAF(field) = 0.079, BSAF(lab) = 0.386

Weltje et al. (2002), snails and bivalves: BCF is 9000 - 250000 and 14000 - 30000, respectively

Weltje et al. (2002), aquatic plants: BCF is 2000 - 300000

 

The investigations showed that basically, Lanthanum has potential to bioaccumulate. But due to the poor water solubility, the bioavailable lanthanum ions released from Lanthanum carbonate is considered to be unlikely under environmental conditions. Moreover, the potential of gastrointestinal absorption and cuticular uptake of Lanthanum carbonate is expected to be low. Most Lanthanum carbonate ingested will be excreted soon. Therefore, bioaccumulation of Lanthanum carbonate is not to be expected.