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.