Distribution Characteristics and Ecological Risk Assessment of Arsenic in the Surface Sediment of Bohai Sea

Abstract

Arsenic is a carcinogen to both humans and animals. Thirteen typical surface sediment samples were taken at Tanghe and Daihe in Qinhuangdao, April, 2011. Hydride generation atomic fluorescence spectrometry (HG-AFS) was used to analyze arsenic (As) concentration. The correlations of sediment arsenic and sediment organic matter (SOM), pH, river water arsenic were discussed. Index of geoaccumulation (Igeo) and potential ecological risk index were cited to assess the arsenic pollution level and its potential ecological risk. The results show that, arsenic in river water sediment, estuary sediment and coast sediment of Daihe are lower than the average level of other Chinese rivers. Arsenic Igeo of these sediments are cleanliness. However, Arsenic concentration in the sampling points of Tanghe is higher than the average level of domestic rivers except river water sampling points. Their Igeo are light pollution. The potential ecological risk index of the two rivers are slight ecological harm. Arsenic concentration of different sampling points in the two rivers distributes as: estuary sediment As>coast sediment As> river water sediment As. The correlation among sediment arsenic, water arsenic, SOM and sediment pH are: 1) Arsenic in sediment has a extremely significant positive correlation with that in water at p<0.01; 2) Sediment arsenic shows a significant positive correlation with SOM at p<0.05; 3) However, there is a negative correlation between sediment pH and sediment arsenic.