Bioaccumulation, described

The environmental fate of chemicals describes the processes by which chemicals move and are transformed into the environment. Environmental fate processes that should be addressed include persistence in air, water and soil reactivity and degradation migration in groundwater removal from effluents by standard waste-water treatment methods and bioaccumulation in aquatic or terrestrial organisms. 

Table 2 includes an example of bioaccumulation, as described by Larsson et al. [48], where estrogen concentrations 4 to 6 orders of magnitude higher than those in water were found in the bile of a rainbow trout caged downstream of WWTPs. 

The octanol-water partition coefficient, Kow, is the most widely used descriptor of hydrophobicity in quantitative structure activity relationships (QSAR), which are used to describe sorption to organic matter, soil, and sediments [15], bioaccumulation [104], and toxicity [105 107J. Octanol is an amphiphilic bulk solvent with a molar volume of 0.12 dm3 mol when saturated with water. In the octanol-water system, octanol contains 2.3 mol dm 3 of water (one molecule of water per four molecules of octanol) and water is saturated with 4.5 x 10-3 mol dm 3 octanol. Octanol is more suitable than any other solvent system (for) mimicking biological membranes and organic matter properties, because it contains an aliphatic alkyl chain for pure van der Waals interactions plus the alcohol group, which can act as a hydrogen donor and acceptor. 

The modified terrestrial-aquatic model ecosystem described here has been found to be a useful tool in studying the environmental fate of drugs and related residues present in animal excreta used as manure. The operation of the ecosystem is relatively simple and yet it allows one to study the complex metabolic transformations of a drug or related residues in its various components. Especially interesting is the study of the degradation of a compound in the soil in the presence of microorganisms found in the animal excreta. This information is important since it eventually determines whether a compound and/ or its metabolites will bioaccumulate in the various elements of the environment. 

The scientific community provided much of the original impetus for improved environmental protection in Sweden. Swedish scientists, for instance, focused attention on the health hazards from organic mercury compounds used in agriculture several years before the Minimata poisonings in Japan brought those problems to the attention of the rest of the world.1 The Swedish chemist Soren Jensen was the first to describe the bioaccumulation properties of PCBs, and the pioneering radiation and biochemical re-... 

Parameters Used to Describe Experimental Bioaccumulation Data... 

Figure 10.5 Terms and parameters frequently used to describe accumulation of chemicals in aquatic organisms. Note that the term bioaccumulation (BAF,) is used to describe the total accumulation by all possible routes (e.g., passive uptake, intake by food and digestion, etc.). The term bioconcentration is sometimes...

Describe in words, the parameters (1) bioconcentration factor, (2) biomagnification factor, (3) biota-sediment- and biota-soil- accumulation factor, and (4) bioaccumulation factor. 

Source Predicted bioaccumulation factors were based upon their relative lipophilicity as described by, D. Mackay, Environ. Sci. Technol. 1982, 16 274-278. 

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