생물학적 이용성과 Aging 이 오염토양의 정화수준 결정에 미치는 영향

Abstract

Organic contaminants become progressively persistent in the environment and hence less available to living organisms and extraction. This phenomenon has been termed aging or sequestration. As a result of aging, remediation efforts for cleaning up organic chemical-contaminated sites have been challenged in removing so called "aged fractions" which are not practically (bio)degraded or extracted. Some portion of persistent organic chemicals may still be present in a site of interest where extensive remedial efforts have been applied. Data collected so far demonstrate that aged fractions of toxic pollutants behave much differently from unaged fractions in the environment so that, in most cases, they do not exhibit the chemicals inherent toxicity. Aged fractions are less mobile, less bioavailable. and desorption- and extraction-resistant. Such facts have resulted in a great impact on remediation practices and risk assessment paradigm by altering exposure frequency and pathways of soil pollutants to receptors. As a consequence, the concepts of environmentally acceptable endpoint and risk-based remediation have emerged. However, it is worthwhile noticing that the degree of aging of a contaminant in a site and the availability of aged fractions should be determined on a site basis since aging phenomenon seems to be chemical-and soil-specific. Therefore, determination of acceptable endpoint of pollutants of interest at a site is a prerequisite for the successful performance of risk-based remediation.