Aging, bioavailability, and overestimation of risk from environmental pollutants

As they persist, or age, in soil, organic compounds become progressively less available for uptake by organisms, for exerting toxic effects, and for biodegradation and bioremediation by microorganisms. This declining bioavailability is not reflected by currently used methods for the chemical analysis of soils for determining concentrations of organic pollutants. As a result, such methods overestimate exposure, and thus risk, from toxic chemicals in contaminated sites.