Bio concentration Factors

Guppies exposed to TPhTCl died as soon as a body burden 20 10 nM was reached. Accumulation of TPhTCl can be predicted using kinetic parameters41. The bio-concentration factors of both TBTC1 and TPhTCl via gill intake of goldfishes reached a plateau after 21 days of exposure42. 

BCF Bio concentration Factor sediment-to-fish has accumulation factor 4 NOEC biota to construct SSD in Figure 5... 

Bioconcentration in aquatic organisms occurs as a result of partitioning between the organism lipid and the surrounding water. If a substance is lipophilic, then equilibrium occurs with a relatively high Bio concentration Factor KB), or the organism/water partition coefficient. For example, the KB value ofpp1-DDT is 79,400 (log KB 4.9), heptachlor, 7900 (log KB 3.9)... 

Sijm, D.T.H.M., Middlekoop, J., Vrisekoop, K. (1995) Algal density dependent bio-concentration factors of hydrophobic chemicals. Chemosphere 31(9), 4001 4012. 

Veith, G.D., Defoe, D.L., Bergstedt, B.V. (1979b) Measuring and estimating the bio-concentration factor of chemicals in fish. J. Fish Res. Board Can. 26, 1040-1048. 

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] ... 

Instead of BCF sometimes the abbreviation Kg is also used, however, for clarity we do not recommend the use of this abbreviation. For aquatic organisms three different bio concentration factors (BCF) can be given [13] ... 

It is known that for very hydrophobic chemicals it can take a very long time (months to years) to reach steady-state concentrations in fish and other organisms. If the BCF value is calculated by dividing the non-equiUbrated chemical level in fish by the chemical concentration in water, the bio concentration factor is underestimated. However, steady-state residue concentrations can be extrapolated if the half-lives or elimination rate constants are available. 

It was also found that the bio concentration potential is dependent on the age, sex, and species of the aquatic organisms. Many of these factors can be eliminated if the test is performed under identical conditions with the organisms of the same species, strain, sex, age, etc. or if the bio concentration factor is related to the lipid content of the organism (see Sect. 5.4). Some other important factors which may affect the bio concentration potential of chemicals in fish and other aquatic organisms are the toxic effects, bio availability, concentration of the chemicals in water, pH of the water, and especially the lipid content of the organisms. These factors will be discussed in more detail in the following sections. 

BCF data reported for very lipophilic and super-hydrophobic chemicals in many cases have been underestimated from experiments with high content of particulate or dissolved organic matter. Bio concentration factors must be related to the bio available chemical concentration in the water, because only the truly dissolved fraction of the chemical is actually bioavailable [5,13,30] (see also Sect. 8.2). 

The real bio concentration factor on a lipid basis (BCFl) of a chemical should be independent of its concentration in the water. In all cases, however, where bioconcentration factors differ by some orders of magnitude for the same chemical, although they have been determined under nearly equal experimental conditions with fish of the same species, strain, sex, age, body weight, and lipid content, it has to be questioned whether a true bioconcentration factor was found. Consequently, all other experimental conditions have to be reexamined. 

LR, least-squares regression method GM, geometric mean fimctional regression method. BCFw, bio concentration factor on a wet weight basis. 

Bio concentration factor in fathead minnows determined by Brooke [395]. 

Bio concentration factor on a wet weight basis of C-ethinylestradiol ( C-EE2 mean measined concentration in water 12 ng 1 ) in fathead minnow after 239 days post hatching determined by R. Lange, T. H. Hutchinson, C. P. Croudace, G. H. Panter, J. P. Sumpter (1999) Environ Toxicol Chem (in preparation). 

Table 12. Bio concentration factors on a wet weight (BCF ) and on a lipid basis (BCFl) of Mirex in fish in dependence on the concentrations in the ambient water (Flow- through system)...

No. Fish species Body weight (g) Lipid content (%) Mean concentration of Mirex in Time of uptake (days) Bio concentration factor (BCF) ... 

BCF Bio concentration factor on a wet wt. basis. BCFl Bio concentration factor on a lipid basis. 

A recent study by Vetter et al. [225] showed that 11 polychlorinated bornanes were abundant in different seal species. The most important persistent 7 polychlorinated bornanes with their lUPAC name, different abbreviations, chemical structure, molecular formula, n-octanol/water partition coefficient (log Kqw) and predicted bio concentration factors (BCF and BCFl) in fish are compiled in Table 13. The predicted BCFl values of hepta-, octa- and nonachlorobornanes are between 600,000 and 71,000,000, and the predicted BCF values of these congeners in fish with 5 % lipid range from ca. 32,000 to 3,500,000. Furthermore, in Table 13 the BCF and BCFl values of two polychlorinated bornane congeners (Parlar No. 26 and No. 50) are included, which were calculated by the authors from the measured concentrations in zooplankton and different fish species and the water of a Canadian fresh water lake [226]. It is obvious that the BCF values of the chlorinated bornanes calculated from concentrations in aquatic organisms and water from the environment are by a factor between 1 and ca. 70 greater than the BCFs predicted from the log values. This can be explained in part by bio accumulation. 

Spehar et al. [231] investigated the bioconcentration potential of hexachloro-norbornadiene and heptachloronorbornene using 30-day flow-through test with early juvenile fathead minnows Pimephales promelas) with a body weight of 0.12 g and 4% lipid content. The measured mean concentrations of hexa-chloronorbornadiene (HCND) in water was 20.0 3.9 pg and the water concentration of heptachloronorbornene (HepCNB) was 25.9 3.4 pg b. The bioconcentration factors on a wet weight basis after 30 days in this fish species were 6,400 and 11,200, respectively. The bio concentration factors on a lipid basis (BCFl) of HCND and HepCNB after 30 days were 160,000 and 280,000, respectively (see Table 13). 

However, in 1985 Oliver and Niimi [251] investigated the bio concentration of hexabromobenzene (HBB) and other highly lipophilic organic chemicals in a flow-through test in rainbow trout Oncorhynchus mykiss). After 96 days, they found a bio concentration factor (BCF ) on a wet weight basis of 1400 (lipid = 7.6%) and a BCFl value of 18,000. But these authors stated also that no steady-state after 96 days was reached. However, the metabolism of HBB was not investigated. Nevertheless, these experiments by Oliver and Niimi [251] have clearly shown that hexabromobenzene can be taken up from water by fish and is bio concentrated to a relatively high amount. However, the BCFl value of HBB is lower than predicted from its Kqw value. 

Water solubility is one of the major parameters which affect the fate and distribution in the environment. Hydrophobic compounds with high octanol-water partition coefficients tend to bio accumulate. Opperhuizen and Voors [63] have shown that hydrophobicity of PCDEs determines the bio concentration factor of PCDEs and that bioconcentration kinetics of PCDEs resemble those of PCBs. 

Biomagnification of PCDEs in food chains has not been studied much. Their food-chain bio accumulation potential, however, is high because their n-octa-nol-water coefficients are high [59]. Log K(1W values of PCDEs 29 and 77 determined by Opperhuizen and Voors [63] were 5.44 and 5.78, respectively. The bio-concentration factors (ml g1) were 1.5 x 104 and 3.2 x 10 respectively, being similar to those of corresponding PCBs. 

Organic hydrophobic chemicals tend to be stored in the lipid parts of an organism. Differences in Hpid content between organisms thus result in differences in bio concentration factors. Therefore, the BCF in fish is usually normalized for the lipid content of the studied organism [22], resulting in... 

The biomagnification factor (BMP) is equal to the ratio of the uptake and elimination rate constant at steady state, similar to the bio concentration factor ... 

The most persistent nonionic surfactants are based on alkylphenol ethoxy-lates. These ethoxylates are only moderately accumulated by marine fauna. The bio concentration factors in common mussels Mytilus edulis) decreased from 350 to 50 from nonylphenol to nonylphenol tri-ethoxylate [150]. 

Bio concentration factor (BCF) The biological accumulation factor associated with direct uptake of a substance from the water in the absence of at r possible intake through the food chaim... 

The dependency of the physico-chemical properties on the chain length causes a different distribution pattern for the different PFC. The longer the perfluorinated carbon chain, the higher the bio-concentration factors and the higher the tendency to adsorb to solid matrices. Thus short chain PFC are more likely to be found in aqueous matrices whereas long chain PFC are predominantly in solid matrices. 

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