Contents and evaluation of heavy metals in whale shark from China's eastern coast

The aim of this study was to provide the information of the heavy metals content in different tissues of whale shark for the references of colleagues who study the heavy metals of marine fish. The contents of heavy metals in the muscle, liver, epidermis and gill of whale shark from the east coast of China were investigated. The contents of copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), Hg (total mercury) and iAs (inorganic arsenic) in these organs and tissues were measured with an atomic absorption spectrophotometer (AAS) and atomic fluorescence spectrophotometer (AFS). The results showed that the average contents of Cu, Zn, Pb, Cd, Hg and iAs in different tissues were 1.69-22.04 μg/g, 7.43-141.29 μg/g, 0.30-4.46 μg/g, 0.11-31.75 μg/g, 0.00022-0.011 μg/g and 0.16-0.64 μg/g (wet weight), respectively. Six heavy metals contents in whale shark were in the order of Zn>Cu>Pb>Cd>iAs>Hg. Compared with other study results, the hepatic Cu concentration of whale shark is higher than that of Pacific sleeper sharks and Greenland sharks. However, the heavy metal levels of muscle are consistent with those reported by other studies of marine fish species. The marine heavy metals pollution status was reflected by the data obtained, the level of Hg of ocean may ascend from 2007 to 2010. Additionally, fresh whale shark was a dangerous food based on the comparison with limits of the Food and Agricultural Organization of the United Nations (FAO).