[en] The Northern Adriatic Sea was interested by continuous direct discharge of phosphogypsum from a local phosphate fertilizer industry up to 1985 following a productive activity of about twenty years.As it is known, due to the remarkable amounts of natural radioactivity connected with the productive cycle of fertilizers from phosphate ores, the release to the environment of huge amounts of potentially hazardous wastes might be in principle of major radioecological concern.In this respect Ra-226 and its decay products are expected to be the main responsible of radioactivity background enhancement.Taking into account that discharge at sea (depth 30-35 m) was interrupted over ten years ago, following the closing of the plant, the main scope of this investigation was to assess the long-term effect of the disposal of phosphogypsum in the marine environment and in particular the possible enrichment of the radioactive fraction after solubilization of the gypsum carrier. In order to assess the actual radioecological influence of discharged slurries on the marine environment a preliminary sampling was carried out.Radioactivity data obtained from sediment cores clearly indicate anomalies in respect to typical 'background' values obtained from homologous samples collected in an unaffected area in proximity of the disposal site.As an example, Ra-226 activities in sediment were found to be one hundred fold higher than natural background.Radioactivity data from sediments cores collected in sites interested by bottom sea currents coming from discharge area will be also reported and discussed.(authors)