PAHs, bioconcentration factors

PAH bioconcentration factor (BCF) for selected species of aquatic organisms... 

Table 25.6 PAH Bioconcentration Factors (BCF) for Selected Species of Aquatic Organisms...

Eadie, B.J., W.R. Faust, P.F. Landrum, and N.R. Morehead. 1984. Factors affecting bioconcentration of PAH by the dominant benthic organisms of the Great Lakes. Pages 363-377 in M. Cooke and A.J. Dennis (eds.). Polynuclear Aromatic Hydrocarbons Mechanisms, Methods and Metabolism. Battelle Press, Columbus, OH. 

Because PAHs are hydrophobic, they tend to accumulate in lipids of organisms that are unable to metabolize them. There are several partition coefficients that can describe the accumulation of PAHs in organisms. Direct partitioning of aqueous phase PAHs to an organism is described by the bioconcentration factor ... 

This study was undertaken to test the ability of our previous molecular connectivity models to accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, alkenylbenzenes, chlorobenzenes, polychlorinated biphenyls, chlorinated alkanes and alkenes, heterocyclic arid substituted PAHs, and halogenated phenols. Tests performed on large groups of such compounds clearly demonstrate that these simple nonempirical models accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of the above compounds. Moreover, they outperform traditional empirical models based on 1-octanol/ water partition coefficients or water solubilities in accuracy, speed, and range of applicability. These results show that the molecular connectivity models are a very accurate predictive tool for the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of a wide range of organic chemicals and that it can be confidently used to rank potentially hazardous chemicals and thus to create a priority testing list. ... 

Fig. 2. Bioconcentration factors (BCF) for Rhepoxynius abronius determined with dry weight divided by interstitial water concentration. Closed symbols, calculated with total PAH in interstitial water open symbols, BCF calculated with free PAH in interstitial water (where large X is the predicted BCF (data from...

Murray AP, Richardson BJ, Gibbs CF (1991) Bioconcentration factors for petroleum hydrocarbons, PAHs, LABs, and biogenic hydrocarbons in the blue mussel. Mar Pollut Bull 22 595-603. 

PAHs are widely distributed in the environment as evidenced by their detection in sediments, soils, air, surface waters, and plant and animal tissues. However, the ecological impact of PAHs is uncertain. PAHs show little tendency for bioconcentration despite their high lipid solubility (Pucknat 1981), probably because most PAHs are rapidly metabolized. Sims and Overcash (1983) list a variety of research needs regarding PAHs in soil-plant systems. Specifically, research is needed to establish the rates of PAH decomposition in soils the soil PAH levels above which PAH constituents adversely affect the food chain and enhancement factors that increase degradation rates of PAHs, especially PAHs with more than three rings. Once these factors have been determined, PAH disposal into soils may become feasible at environmentally nonhazardous levels. 

Elimination Kinetics. Determination of the rate of elimination is a useful exercise that can be used to calculate the half-life ty and determine the persistence of PAHs in tissue, in addition to modeling steady-state tissue burdens. The balance between uptake and elimination will determine the bioconcentration or bioaccumulation factor, which can be compared to an expected value (for example, see BCFpred in Appendix). Computation of half-life is also a good benchmark for interspecific comparison of the per-... 

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