Biota, cadmium concentration

Studies of 30-60 days duration with three comparatively sensitive species of freshwater Ashes demonstrated that concentrations of >1.0 and < 3.0 xg Cd/L in water of low alkalinity caused reductions in growth, survival, and fecundity of brook trout (Salvelinusfontinalis), the most sensitive species tested. Under conditions of increasing alkalinity, the maximum allowable cadmium concentration range for brook trout increased to >7.0 and <12.0 p-g/L a similar case was made for the walleye (Stizostedion vitreum vitreum). Among all species of freshwater biota examined, cadmium concentrations of 0.47-5.0 pg/L were associated with decreases in standing crop. 

Lethal concentrations (LC) of cadmium to freshwater biota during various exposure intervals... 

Table 1.3 Lethal Concentrations (LC) of Cadmium to Freshwater Biota during Various Exposure Intervals (Concentrations shown are in pg Cd/L (ppb) of medium fatal to 10% or 50% of test organisms)... 

Sublethal effects in birds are similar to those in other species and include growth retardation, anemia, renal effects, and testicular damage (Hammons et al. 1978 Di Giulio et al. 1984 Blus et al. 1993). However, harmful damage effects were observed at higher concentrations when compared to aquatic biota. For example, Japanese quail (Coturnix japonica) fed 75 mg Cd/kg diet developed bone marrow hypoplasia, anemia, and hypertrophy of both heart ventricles at 6 weeks (Richardson et al. 1974). In zinc-deficient diets, effects were especially pronounced and included all of the signs mentioned plus testicular hypoplasia. A similar pattern was evident in cadmium-stressed quail on an iron-deficient diet. In all tests, 1% ascorbic acid in the diet prevented cadmium-induced effects in Japanese quail (Richardson et al. 1974). In studies with Japanese quail at environmentally relevant concentrations of 10 pg Cd/kg B W daily (for 4 days, administered per os), absorbed cadmium was transported in blood in a form that enhanced deposition in the kidney less than 0.7% of the total administered dose was recovered from liver plus kidneys plus duodenum (Scheuhammer 1988). 

J. J. Darbonne, M. G. Heagler, Concentrations of cadmium, lead, nickel and vanadium in biota from marsh restoration sites in southwest Louisiana, Microchem. J., 60 (1998), 242-248. 

Metal release from tidal Elbe river sediments by a process of oxidative remobilization has been described by Kersten (1989) (Figure 8.2). Short (30-cm) sediment cores were taken from a site, where diurnal inundation of the fine-grained fluvial deposits take place. In the upper part of the sediment column, total particulate cadmium content was 10 mg kg whereas in the deeper anoxic zone the total particulate concentration of Cd was 20 mg kg h Sequential extractions indicate that in the anoxic zone 60 -80% of the Cd was associated with the sulfidic/organic fraction. In the upper (oxic and transition) zone, the association of Cd in the carbonatic and exchangeable fractions simultaneously increase up to 40% of total Cd. This distribution suggests that the release of metals from particulate phases into the pore water and further transfer into biota is controlled by the frequent downward flux of oxygenated surface water. From the observed concentrations, it would be expected that long-term transfer of up to 50% of the Cd from the sediment subsurface would take place either into the anoxic zone located further below the sediment-water interface or released into the open water. 

Tab. 6.5 Concentrations of cadmium in biota (Eisler 1985) (see also Table 6.4)...

A review of concentrations of mercury, cadmium, lead, PCBs, DDT and metabolites, and HCH in water, sediments, and biota in coastal as well as open ocean areas of the world has been published [42]. 

---