Assessment on Heavy Metals in Edible Bivalves in Dandong Market

From April to July 2012, four species of univalves were selected and 60 samples were chosen from each species of univalves by random sampling in Dandong market. The heavy metal contents of Pb, Cd, Cr, Cu, Zn, total As and total Hg in the edible parts of the univalves were determined by using incomplete digestion - AAS method, and the assessment on the pollution situation of the four species of univalves was made by using the single factor index method. The results showed that bullacta exarata was slightly polluted by Zn, the pollution index was 0.65, and the edible value was threatened, which should be paid attention to. The heavy metal contents in the edible parts of the other univalves were far lower than the pollution limit of the national standard of food safety and the edible value was safe. The heavy metal accumulation ability in bullacta exarata is higher than in the other three species of univalves. Bullacta excta should be the biological indicator for the monitoring of heavy metal pollution.