Daphnia bioconcentration factors

The bioconcentration factor (BCF) for chromium(VI) in rainbow trout (Salmo gairdneri) is 1. In bottom-feeder bivalves, such as the oyster (Crassostrea virginica), blue mussel (Mytilus edulis), and soft shell clam (Mya arenaria), the BCF values for chromium(III) and chromium(VI) may range from 86 to 192 (EPA 1980, 1984a Fishbein 1981 Schmidt and Andren 1984). The bioavailability of chromium(ni) to freshwater invertebrates (Daphnia pulex) decreased with the addition of humic acid (Ramelow et al. 

Fig. 5. Relationship between the steady-state bioconcentration factors on a wet weight basis (BCFw) of lindane (y-HCH) in mussel, Daphnia, and different fish species and their lipid content (Lw in % on a wet weight basis). The highest BCF values 3860 and 4240 were calculated for eels from the outdoor environment. From Geyer et al. [40] (with permission)...

The EU classifies pentaBDE as R50/50, "Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment."This decision is based on the EC50 value of 0.014 mg/l seen in a 48-hour Daphnia study, the lack of biodegradation, and the high bioconcentration factor (p.15). 

Analogous relationships between BCF and other descriptors, generally collinear with log have been derived such as water solubility (Metcalf et ai, 1973, 1975 Chiou et aL, 1977 Kenaga and Goring, 1980). The bioconcentration factors for Daphnia, molluscs, mussels, algae and microorganisms have also been related to log P or water solubility (Table 4.14). 

ECOLOGICAL PROPERTIES Aquatic toxicity. Zebra fish, 96-h LC50 Aquatic toxicity, Daphnia magna, 48-h, EC50 Bioconcentration factor Partition coefficient mg 1- mg 1-1 49.3-437.1 (in carp logKow >100 69/24H 30 days) 10.03... 

Southworth etaL (1978) reported that elimination rates in the cladoceran Daphnia pulex increased in the order perylene>benz[a]anthracene= methylanthracene > pyrene > phenanthrene > anthracene > naphthalene. Hence, naphthalene often occurs in relatively low concentrations in natural invertebrate populations. Anderson etal. (1976) demonstrated that methyl-derivatives of naphthalene were retained in invertebrates longer than the parent compound owing to a decrease in solubility and rate of volatilization. Varanasi and Malins (1977) reported bioconcentration factors of 2, 8, 17, and 27 for clams Rangia cuneata exposed to naphthalene, methyl-naphthalene, dimethylnaphthalene, and trimethylnaphthalene, respectively. 

Bioconcentration is the result of direct uptake of a chemical by an organism only from water. Experimentally, the result of such a process is reported as the bio concentration factor (BCF). Consequently, the BCF is defined as the ratio of steady state concentration of the chemical in aquatic organisms (Cp) such as fish, mussels, water flea (Daphnia), algae etc. and the corresponding freely dissolved chemical concentration in the surrounding water (Cw) [2a,b,c, 4, 10-14] ... 

Table 4. Summary of regression analysis for bioconcentration of organic chemicals by algae, water flea (Daphnia), mussels, and different fish species. Furthermore, the equation to predict the bioaccumulation factor (BAF) of chemicals in human (fat) is presented...

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