ABSTRACT
Remediation of contaminated sites is often established on the basis of risk assessments that rely on both toxicological impact on ecosystem and human health. The success of bioremediation, contaminated site rehabilitation and production of contaminant free food is largely dependent on the availability of the contaminants for plants, animals and m icrobial biota in the terrestrial environm ent. C onsequently 'bioavailability' is used as the key indicator of potential risk that contaminants pose to both environmental and human health. However, the definition of the term 'bioavailability' and the concept on which it is based are unclear, the methods adopted vary throughout the world and therefore there is no single standard technique for the assessment of either plant availability of contaminants or their ecotoxicological impacts on soil biota. In this book, while attempting to define the bioavailability, we have taken into consideration that bioavailability is a function of both soil, nature of contaminant, species/receptor organisms and environmental perturbations including the duration of contamination (i.e., contaminant ageing).
