ECOLOGICAL CHARACTERIZATION OF AN ABANDONED OPEN QUARRY USED FOR DISPOSAL OF PHARMACEUTICAL WASTES

Studying soil using an ecosystem approach is a necessary prerequisite for improving the understanding and management of its biodiversity and for developing a solid reserve of tools for evaluating and monitoring its state. Micro-organisms are essential components of ecosystems: they are the main mediators in detritus-based food web and make it possible for the energy contained in dead organic matter to be used by detritivores, are responsible for the complete mineralization of organic matter and recycling of nutrients, and are, finally, capable of performing a homeostatic action with exogenous molecules; the last is only possible to the extent that the quantity and toxicity of the molecules do not hamper or inhibit their activity. The presence of an abundant and varied microbial community is a necessary requisite for an immediate and effective response to the various natural and anthropic disturbances that can affect an ecosystem. The study of microbial communities is highly dependent on the availability of appropriate methods for identifying their structures (e.g. number and diversity of species) and their function (e.g. bacterial activities). We report some results regarding the study of soil and related groundwater quality of an Italian area contaminated by pharmaceutical residuals, using microbiological indicators. The microbiological indicators used were: the bacterial abundance (epifluorescence microscope total direct counts), the cell viability, the species diversity by assessing the bacterial community structure with the fluorescence in situ hybridization method (FISH) and the soil microbial activity by measuring the dehydrogenase activity. The overall results show a low quality state of both soil and groundwater monitored in terms of bacterial viability, activity and diversity.