Up to this point, bioaccumulation and the various related phenomena (e.g., biomagnification, bioavailability, biotransport, etc.) have been discussed only in a conceptual framework. Yet in practice, the ability to determine bioaccumulation potential is a major endeavor of health regulatory agencies in performing risk assessments for pollutants of ecological concerns.

Once a pollutant is suspected to be a potential bioaccumulant, its concentrations will be measured in ambient media (usually water) and estimated in relevant organism tissues. The bioaccumulation potential for this pollutant is then qualified by a bioconcentration factor (BCF) value, which is usually measured as the ratio of the chemical�s residues in aquatic organisms (usually fish) to its level in ambient water (Code of Federal Regulations, 2003).

In the USA, pollutants are considered bioaccumulative if they have a degradation half-life > 30 days, a BCF > 1,000, or a log K_ow value > 4.2 (Corl, 2001; U.S. EPA, 1999, 2000). These values are below those adopted by Canada (CEPA, 1999) and many other Western countries.

Half-life is a measure of the time it takes for half of the material�s initial amount to be degraded. The chemical property K_ow is an octanol-water partition coefficient, which is the ratio of a chemical�s concentration in the octanol phase to its concentration in the water phase quantifying the potential for partitioning into organic matter. K_ow is inversely related to the compound�s water solubility; it represents the compound�s tendency to partition itself between an organic phase (e.g., a fish, a soil) and an aqueous phase. Its logarithmic form (log K_ow) is used in models to estimate bioaccumulation factors in fish, plants, etc.