Pollution of surface sediments and its assessment of potential ecological risk in the Yangtze Estuary

Through analyzing the contents of typical pollutants (PCB,Hg,Cd,Pb and As) in surface sediments of the Yangtze Estuary, with adopting pollution parameter techniques of single factor and Hakanson potential ecological risk index techniques,Based on the monitoring data of surface sediments in the Yangtze Estuary(Aug., 2004,),the quality status of these sediments were evaluated. The degree of potential ecological risks on these sediments ,the main factors of environment pollution and potential ecological risks in them ere determined quantitatively; The variation trends on the integrated potential ecological risks of these sediments and single potential ecological risks of every typical pollutants in them were analyzed. The results showed that the order of pollution extents of every typical pollutant was AsPbHgPCBCd. The average integrated index of all typical pollutants cd was 1.37,with rather good sediment quality in the Yangtze Estuary,the contents of every typical pollutant was less than reference values,As was main environment pollution factor;The surface sediments of the Yangtze Estuary only possessed rather light potential ecological risks,the sequence of potential ecological risk of different water area was North Shore of the Hangzhou BaySouth Branch of the Yangtze EstuaryNorth Branch of the Yangtze EstuaryOutside of the Yangtze Estuary;Every typical pollutant also possessed rather light potential ecological risks,the sequence of potential ecological risk of different typical pollutants was HgPCBCdAsPb,Hg was main factor of potential ecological risks in the Yangtze Estuary; The variation trends on the integrated potential ecological risks of these sediments and single potential ecological risks of every typical pollutants were increasing in recent years.