Theoretical bioaccumulation potential

In the literature, the estimated chemical s equilibrium concentration, C b , in the organism (i.e., the numerator of Eq. 10-3) is called the theoretical bioaccumulation potential, TBPh and is given by ... 

The estimation of BCF values from log is founded on a relatively profound theoretical basis. However, the predictive power of the respective QSARs should not be overestimated and their limitations must be realized. Principally, QSAR predictions of BCF values correspond to the average accumulation observed with the class of compounds under investigation. The assessment of the potential worst case requires a model that reflects the highest accumulation potential associated with the assumed lipophilicity. The respective bilinear QSAR (Table 4.15) formalizes the empirical rules for estimating log BCF (adjusted for the lipid content of the fish) from log P the bioconcentration potential corresponds to log P. Compounds of high lipophilicity with log P > 6-7 reveal no further increase in BCF. Factors resulting in less bioconcentration are neglected, as the various contributions are not systematically accountable. This procedure is recommended as a conservative approach to a realistic worst-case assessment of the bioaccumulation potential. 

Data were not available in the literature on the dietary exposure of creosote to children. Based on the bioaccumulation of creosote constituents in fish and other aquatic organisms, and the potential for uptake or contamination in plant food sources, dietary exposure is theoretically possible, but is unlikely to be significant. An exception to this may be in residential areas such as that built on the old Koppers Company, Inc. site. Homegrown produce grown in contaminated soils may provide a significant source of exposure to children. The drinking of chaparral tea may result in oral exposure to wood creosote. 

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