ABSTRACT
Soil quality assessment is of paramount importance to manage soil resources for sustainable future use. This framework is much more important when a remediation program has to be implemented for restoring a polluted environment. Indeed, to assess the results of restoration of polluted sites it is mandatory not only to measure the remaining amount of pollutants still present in the restored environment, or their transformation in non-toxic end products, but also to evaluate the quality of sites in terms of their safety and regain of their original properties. Additionally, it is important to monitor whether and how soil biological functions have been affected by, during and after the remediation process. In this context, two aspects of this matter need to be analyzed: to well identify and define soil quality and to find reliable, reproducible, low-cost and environmentally friendly indicators capable of monitoring the status of a soil and its changes. This chapter will try to give a brief overview on: (i) the basic concepts of soil heath and soil indicators, (ii) enzyme activities suitable to detect soil changes and examples related mainly to polluted soils, and (iii) numerical indexes and some models based on enzyme activities.
