268 ANN IST SUPER SANITà 2008 | V OL. 44, NO. 3: 268-272 RESEARCH FROM ANIMAL T ESTING TO CLINICAL EXPERIENCE Summary. The Water Frame Directive 2000/60/CE underlines the importance of sediments and re- quests the creation of a European net (SedNet) for their management. Sediments play an important role for the river basin and offer a variety of habitats to many aquatic organisms. Microorganisms, such as Clostridia, are indispensable for a lot of symbiotic and pathogenic relationships with higher organisms and the disappearance of these communities could cause extinction of many species. Thus, Clostridia communities represent the most suitable microbiological indicators to characterize the ecological quality of sediments. The creation of SedNet may make it possible to develop a series of best recommendation in sediment management. Key words: microbiological indicators, sediments, water ecosystems, Clostridia. Riassunto (Indicatori microbiologici e gestione dei sedimenti). La Direttiva Europea sulle Acque 2000/60/CE sottolinea l’importanza dei sedimenti e richiede la creazione di una rete a scala europea (SedNet) per la loro gestione. I sedimenti rivestono un ruolo importante per la salute dei bacini idro- graici e forniscono una grande varietà di habitat per molti organismi acquatici. Microrganismi co- me i Clostridi sono indispensabili per numerose relazioni simbiontiche e patogeniche nei confronti di organismi superiori e la loro scomparsa potrebbe causare l’estinzione di numerose specie. Pertanto le comunità di Clostridi rappresentano i più idonei indicatori microbiologici nella caratterizzazione della qualità ecologica dei sedimenti. La creazione della rete SedNet potrà rendere possibile lo svi- luppo di una serie di raccomandazioni sulla gestione dei sedimenti. Parole chiave: indicatori microbiologici, sedimenti, ecosistemi acquatici, Clostridi. INTRODUCTION The European Union recently adopted a series of strategies, directives and recommendations that put the stress on an environmental approach in water monitor- ing, management and restoration. In particular, sedi- ment assumed higher and higher importance in the management of water resources. The Water Frame Directive 2000/60/CE [1] underlines the importance of this matrix and requests the creation of a European net (SedNet) that may work for the holistic approach to this aspect. In particular microbiological indicators rep- resent a fundamental tool to assess the quality state of sediments and to evaluate the related health hazards. About sediments Sediments consist of particulate matter that can be transported by luid low and which eventually is depos- ited as a layer of solid particles on the bed or bottom of water bodies. Sedimentation is deined the process of deposition by settling of a suspended material. The sediment will be transported as suspended load if the low is greater than the settling velocity. Sediments with an suficient diameter to settle but still move are known as bed load and the particles are transported by mechanisms like saltation (jumping up into the low, being transported a short distance then settling again). To characterize and identify pedological struc- tures it is important to use a basic language to fa- cilitate scientiic communication. In the year 1926 the International Society of Soil Science developed, based on the research of Novak, the following con- ventional classiication system (Table 1). This nomenclature in relation to the particle di- mensions can give helpful information about cri- teria of the systematic of the supericial in rela- tion to draining by supericial water, erosions and other forces. Also for a lot of cultures the physical mechanical constitution of the sediment is a funda- mental element. But over all Benton et al. [3] could proof a correlation of sediment grain-size composi- tion on ecotoxicity. Sediment plays an important role for the river ba- sin [4]. Its origin is in the weathering and erosion of minerals, organic material and soils in upstream areas usually after rain or snow melt. The sediment is trans- ported downstreams and settles along the river bed and banks by sedimentation. Because of embank- Microbiological indicators and sediment management Laura Mancini, Sirona Rosemann, Camilla Puccinelli, Simone Ciadamidaro, Stefania Marcheggiani and Francesca Anna Aulicino Dipartimento di Ambiente e Connessa Prevenzione Primaria, Istituto Superiore di Sanità, Rome, Italy Address for correspondence: Laura Mancini, Dipartimento di Ambiente e Connessa Prevenzione Primaria, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy. E-mail: laura.mancini@iss.it.