STEROLS IN SEDIMENT SAMPLES FROM VENICE LAGOON, ITALY

Sterols of different origin were analysed in sediment samples collecte d in the Venice Lagoon. The purpose of the study was to investigate th e degree of sewage contamination within the Lagoon using fecal sterols (coprostanol, epicoprostanol and coprostanone) and to analyse the pat tern of the sterols to plot the origin of the organic matter. Sediment ary coprostanol at Canal Grande within the city of Venice was more tha n one order of magnitude higher than other stations in the Lagoon and two orders higher than in a sediment sample collected in the open sea. The cholesterol/coprostanol ratio, like the percentage of coprostanol in total sterols at this sample site was very similar to values in se wage sludge. The different pattern of sterols at station 2 which had t he largest amount of total sterol indicates a difference in the origin of the organic material. Nevertheless the sterols used as tracer of t errestrial vascular plants did not show any particular trend at this s tation, receiving fresh water inputs. beta-sitosterol and cholestanol reached the highest levels at the station within the Chioggia basin. C opyright (C) 1996 Elsevier Science Ltd