Contents and evaluation of heavy metals in common aquatic from Lingding Yang in Pearl River estuary, South China Sea

The contents of heavy metals in 14 species of common aquatic，including fishes, shrimps, bivalves and cephalopods collected from Lingding Yang in the Pearl River estuary of South Chian Ocean were investigated. The contents of cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), chromium (Cr) and nickel (Ni) in all aquatic were measured with a FAS. The standard reference materials Standard Oyster Tissue 1566 were also digested and analyzed with a FAS for quality control. Metal pollution index was used to compare the otherness between different organisms, and the Evaluation standards of trace metal elements in aquatic organisms and the Limiting standard of noxious and nocuous matters for aquatic products were introduced to evaluate the pollution levels and edible security. The results showed that there was an aggravating trend in metal pollution at the Pearl River estuary. Aquatic all received heavy metal contamination in different degree, even reached seriously polluted.Trace metals in many sea foods greatly exceeded the edible standard. For example, highest concentration of Cr and Pb in Collichthys lucidus were 23.93 and 48.05 times higher than the edible standard, respectively，Pb in Saurida elongate was 52.66 times higher than the standard，and Cu and Cd in Crassostrea rivularis were 740.27 and 89.59 times higher than the standard, respectively. A significant difference was found in enrichment ability between different organisms. The results indicated that the pollution of heavy metals in Pearl River estuary has actually threatened the health of consumers.