Vanadium carbide

Bioaccumulation: aquatic / sediment

Description of key information

Several relevant studies are available on bioconcentration (BCF) or bioaccumulation (BAF) of vanadium in fish and invertebrates. However, reliable studies (Klimisch 1 or 2) could not be identified (e.g., standard studies not available, V concentration in exposure medium was not measured). The available data on fish and invertebrates based on information on measured V concentration in whole organisms (or whole soft tissue for bivalves) and nominal V concentration of the exposure medium were used in a weight-of-evidence approach. Data are available from laboratory tests with pentavalent (V2O5, NaVO3, NH4VO3, Na3VO4) or tetravalent (VOCl2) V substances and monitoring studies measuring V concentrations in aquatic organisms and the environment. Data are available for 5 fish species (freshwater and marine), 1 freshwater invertebrate species and 12 marine invertebrate species, including bivalves, crustaceans and echinoderms. Whereas the majority of results are based on organism’s wet weight, some BAF values for invertebrates are reported based on dry weight and could thus not be included in the weight-of-evidence approach. The median BCF or BAF values for fish and invertebrates are 8.1 (range 0.5–412) and 12.1 (range 1.4–900) L/kg wet weight, respectively. The overall median value is 12.0 L/kg wet weight. Regarding the BAF values based on dry weight, a median BAF value of 7.5 L/kg (range: 5.8-438.9) can be derived for invertebrates.

Furthermore, biota-sediment accumulation factors (BSAF) are available from supporting studies (Klimisch 3) for 1 freshwater and 3 marine sediment species, which range from 0.005 to 0.23 with a median BSAF of 0.03.

There is no indication for biomagnification of vanadium in marine food chains (Miramand and Fowler, 1998). Experimental BCF values of fish and invertebrates decrease with increasing vanadium concentrations of the exposure medium (Holdway et al., 1983; Ray et al., 1990; Edel and Sabbioni, 1993; Miramand et al., 1980; Miramand et al., 1981, Jensen-Fontaine et al., 2014). Therefore, the highest BCF values are considered not relevant for contaminated environments.

There is a large discrepancy (up to a factor 100) between BCF values for fish and invertebrates derived during 21-day uptake experiments with labelled 48V and BAF values based on analysis of total V in the same organisms and seawater (Miramand et al., 1980, 1981, 1982 and 1992). The difference was explained by a slow uptake of V, not reaching equilibrium within 21 days, or the contribution from food to bioaccumulation of vanadium. However, a clear conclusions could not be made.

Due to the uncertainty of each individual study, it was decided to apply all BCF and BAF data based on organism’s wet weight in a weight-of-evidence approach. The 5th, 50th and 95th percentiles of the BCF values according to the best-fitting distribution (log Weibull) are 1.3, 12.3 and 366 L/kg wet weight, respectively. The 50th percentile (12.3 L/kg wet weight) was selected for the chemical safety assessment.

Key value for chemical safety assessment

BCF (aquatic species):

12.3 L/kg ww