AN INTEGRATED APPROACH TO THE ASSESSMENT OF THE ENVIRONMENTAL-QUALITYOF THE TIBER RIVER IN THE URBAN AREA OF ROME - A MUTAGENESIS ASSAY (MICRONUCLEUS TEST) AND AN ANALYSIS OF MACROBENTHIC COMMUNITY STRUCTURE

Our aim was to study the environmental pollution of the river Tiber wi thin the urban area of Rome. We studied both the stress of the macrobe nthic communities, described by density (calculated as animal biomass) and diversity (calculated with the Shannon index), and the mutagenic effects of waters and sediments, using the micronucleus test in root t ips of Vicia faba. Four places (stations) were studied: (1) Castel Giu bileo, at the entry of the urban area; (2) Ponte Tor di Quinto, immedi ately after the confluence of the tributary river Aniene; (3) Ponte Ma tteotti, at the entry of the historical city center; and (4) Ponte Sub licio, in the middle of the city center. Samples were collected in spr ing (May, 1989) with an intermediate pollution level, winter (January 1990) with a low one, and late summer (September 1990) with a high one . There is agreement between the environmental damage, measured by div ersity of macrobenthic community, and the mutagenic effect of media (w ater and sediments), identified by micronuclei: while Castel Giubileo shows an acceptable condition in all the seasons, and Ponte Sublicio a bad one, the intermediate stations show a recovery in January.