Cobalt:: freshwaters ecosystems

Ecosystems: 

Key Concerns

Data are available on the toxicity of cobalt to freshwater algae, invertebrates and fish. Seventy two hour EC50 values for growth of an alga (Selanstrum capricornutum) exposed to cobalt in the absence of EDTA range form 0.02 to 0.27 mg/l (Grimwood et al. 1998). Forty eight hour EC50 values for immobilization of Daphnia magna ranged from 1.1 to 1.5 mg/l (Biesinger and Christensen 1972; Khangarot and Ray 1987). Ninety six hour LC50 values for crayfish (Austropotamobius sp. and Orconectes limosus) were 8.8 and 10.2 mg/l, respectively, with corresponding 30 day LC50 values of 0.8 and 0.9 mg/l (Boutet and Chaisemartin 1973). LC50 values for various species of fly larvae (Ephemere lla subvaria, Acroneuria lycorias and Hydropsyche betteni) exposed to cobalt for 4 to 8 days range from 16 to 32 mg/l (Warnick and Bell 1969). Ninety six hour LC50 values for fathead minnow (Pimephales promelasi) and a teleost (Colisa fascialatus) were 12.7 to 24.8, and 102 mg/l, respectively (Srivaastiva and Agrawal 1979; Curtis and Ward 1981). No effects on the growth or survival of zebrafish (Brachydanio rerio) were reported following exposure to a cobalt concentration of 2 mg/l for 96 hours (Grimwood et al. 1998).

Environmental limit: 

Habitat/ Ecosystem Type Critical Load/ Level Status Reliability Indication of exceedance Reference
Freshwaters

3 µg/l

Provisional Environmental Quality Standard (EQS) reliable i.e. a number of published papers of various studies show comparable results

Guideline value for the protection of freshwater life, expressed as an annual mean. The corresponding provisional Maximum Acceptable Concentration (MAC) was 100 µg/l.

1169

References: 

Biesinger, K. E.; Christensen, G. M. 1972 Effects of various metals on survival, growth, reporduction, and metabolism of Daphnia magna Journal of the Fisheries Research Board of Canada 1691-1700
Boutet, C ; Chaisemartin, C 1973 Propriétés toxiques spécifiques des sels métalliques chez Austropotamobius pallipes pallipes et Orconectes limosus Comptes Rendus des séances de la Société de Biologie 1933-1938
Grimwood, M ; Dixon, E ; Bailey, K ; Dunning, J 1998 Proposed Environmental Quality Standards for Cobalt in Water
Khangarot, B. S.; Ray, P. K. 1987 Daphnia magna as a model to assess heavy metal toxicity: comparative assessment with the mouse system Acta Hydrochim Hydrobiol 427-432
Srivaastiva, R. N.; Agrawal, S. J. 1979 Hematological anomalies in a fresh water teleost, Colisa fasciatus on acute exposure to cobalt Acta. Pharmacol. Toxicol 197-199
Warnick, S ; Bell, H 1969 The acute toxicity of some heavy metals to different species of aqautic insects Journal of the Water Pollution Control Federation 280-284