//SYS23///SYS23/D/IPD3B2/JOURN/TEC/3B2/E001019S.3D ± 1 ± 25.7.2000 ± 7:50PM Toxicological and Environmental Chemistry, Vol. 00, pp. 1±9 ' 2000 OPA (Overseas Publishers Association) N.V. Reprints available directly from the publisher Published by license under Photocopying permitted by license only the Gordon and Breach Publishing Group. Printed in Malaysia. AN IMPROVED INDEX FOR MONITORING METAL POLLUTANTS IN SURFACE SEDIMENTS GIANPIERO ADAMI, PIERLUIGI BARBIERI and EDOARDO REISENHOFER Department of Chemical Sciences, University of Trieste, Via Giorgieri 1, 34127 Trieste, Italy (Received 12 April 2000; Revised ; In final form ) An approach for defining the quality of surface sediments of limited areas in terms of heavy metal contents is proposed. Sediments were taken on a bi-dimensional mapping, for checking possible different sources of pollution in the case study, a harbour zone. Non residual metals were determined by ICP-AES in cold diluted hydrochloric acid leachates of sediments. An ``enrichment factor'', r, can be computed for each metal: metals with r values exceeding unity can be considered as indicators of metal pollution. A ``total enrichment factor'', R, was proposed in order to assess the degree of pollution of sediments for each site. R is an adimen- sional value that accounts for the presence of metals that exceed threshold values determined by background concentrations. Keywords: Polluted sediments; metal enrichment factors; HCl sediment leaching; harbour of Trieste INTRODUCTION The seawaters of the harbour of Trieste (Northern Adriatic) are seriously exposed to urban and industrial wastes. The shoreline is densely inhabited, and there are also many industrial and harbour activities: shipbuilding, good stocking, and so on. All that implies both occasional and steady inputs of many chemical species by sewage discharges not completely known and *Corresponding author. Fax: 39-040-6763903. E-mail: reisen@univ.trieste.it 1