Lanthanum chloride, anhydrous

Bioaccumulation: aquatic / sediment

Description of key information

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. (20019, 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

Additional information

No bioaccumulation studies are available for Lanthanum chloride. 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 for naturally occurring substances such as metals, is more complex and most concepts and tools to assess the bioaccumulation were inadequate for the assessment of metals since the methods were originally developed on limited results obtained for neutral lipophilic organic substances that have shown that their potential to bioaccumulate and/or to biomagnify is directly related to the inherent properties of the substance.

However, several field studies are available in which the concentration of Lanthanum is based on the element. Biota of different trophic levels such as molluscs, worms, and crustaceans were investigated in these studies. Furthermore, some of them compared the estimation of the BCF in the field with additional investigations of the natural sediment/surface water and biota in laboratory studies. One study with mixed REE, amongst others the analogue substance Lanthanum trinitrate, in carp is available.

 

Sun et al. (1996) investigated the bioaccumulation of mixed REE nitrate hydrates (amongst others Lanthanum) in Cyprinus carpio. Large variations of BCFs (calculated as the concentration of test substance in fish tissue (mg/kg) divided by the nominal concentration of test substance in the test) were observed for different tissues, the highest BCF was found in the internal organs with a range of 45.2- 828, distinct lower BCFs were stated in the gills, skeleton and muscle which were in the range of 0.44 – 13.8.

 

BCFs, available from field data showed distinct higher BCF values, as reported for molluscs, worms and crustaceans:

 

Sneller et al. (2000) reported BCFs for different species, sampled from 6 locations in the dutch Rhine estuary. The range of the stated BCF for bivalves, worms and crustaceans were 15000 – 50000, 8000 - 120000 and 10000 – 40000, respectively.

 

Stronkhorst and Yland (1998) and Sneller et al. (2000) compared the bioaccumulation in Corophium volutator (amphipoda) in a laboratory and a field study. The calculated BCF in the laboratory examination was 22387 corresponding to the pore water and 107152 corresponding to the surface water, the BCF in the field study was 28840. So the BCF related to pore water was about a factor of 5 lower than the BCF related to the surface water. Probably the BCF related to pore water was more realistic, since the shrimps generally are in contact with the pore water and not with the surface water. The BCF (related to pore water) calculated for the field was higher than the BCF (related to the pore water) calculated for the laboratory experiments. This can be attributed to the fact, that the pore water concentration in the laboratory experiments was increased by the stirred sediment. The BSAF (biota sediment accumulation factor) was low (2.57), induced by the high adsorption of Lanthanum to the sediment.

 

The low BSAF for Corophium volutator was confirmed by Moermond et al. (2001), who stated a BSAF of 0.079 in a field study and 0.386 in a laboratory study.

 

A further field study was conducted by Weltje et al. (2002), who determined the BCF in snails and bivalves at five locations in the Netherlands. The calculated range for the BCF was 9000 – 250000 and 14000 – 30000 for snails and bivalves (on a dry weight basis), respectively. Furthermore the BCF in two aquatic plants (based on dry weight) was investigated: The range of the BCF for Potamogeton pectinatus was 6000 - 300000 based on the concentration in surface water and 2000 - 300000 based on the concentration in pore water. For Lemna minor a range of approx. 10000 - 20000 was stated based on the concentration in surface water.

 

The BCFs, calculated in field studies, showed wide variations of up to three orders of magnitude. This can be attributed to variations in abiotic parameters of different sampling locations as well as to different affinities among organisms to lanthanum. Fishes, which are only tested in the laboratory study by Sun et al. (1996) showed the lowest bioaccumulation potential, compared to crustaceans, snails, bivalves, worms and aquatic plants.

However, bioaccumulation may be underestimated in this laboratory study, because the calculation is based on nominal concentrations in the medium. In addition, actual measured concentrations may not be completely bioavailable: a smaller or bigger part of the total dissolved test substance may not be present in the ionic form, but rather be bound to DOC. Measuring total dissolved Lanthanum concentration may then have repercussions on the calculation of BCFs. Therefore, one must keep in mind that reported BCFs might underestimate the real situation.

Nevertheless, all the investigations showed, that Lanthanum has a potential to bioaccumulate.

It is known that organisms are able to modulate both accumulation and potential toxic impact of internal concentrations of metals through (1) active regulation, (2) storage, or (3) a combination of active regulation and storage over a wide range of environmental exposure conditions. Although these homeostatic control mechanisms have evolved largely for essential metals, it should be noted that non-essential metals are also often regulated to varying degrees because the mechanisms for regulating essential metals are not entirely metal-specific. Chassard-Bouchard and Hallégot (1984) examined the Lanthanum content in Mytilus edulis collected from French coastal waters of the Channel, Atlantic Ocean and. 139La+ was detected within lysosomes of digestive gland, labial palp and gill epithelium, macrophage hemocytes and chitinous tissue. Furthermore, Lanthanum was always associated with high phosphorus contents in the lysosomes. Thus, Lanthanum which exists in sea water at trace level is taken up by the Mussel, via gill and digestive tractus, in a soluble form and then concentrated in the form of an insoluble phosphate in the storage organelles. This process can be assessed as detoxification mechanism, comparable to the process observed after oral uptake of Lanthanum in vertebrates.

Chassard-Bouchard, C. and Hallégot P. (1884): Bioaccumulation of lanthanum by the mussels Mytilus edulis collected from French coasts. Microanalysis by X-ray spectrography and secondary ion emission. C R Acad Sci III. 298(20): 567 -572