Determination and Evaluation of Heavy Metal Content of Freshwater Economic Fish in Northeast Guangdong

Concentrations of lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn) and manganese (Mn) were measured in various organs (such as in liver and muscle) from 9 species of freshwater economic fishes which were collected from northeast area of Guangdong Province. The concentration of metals was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). Results showed that the levels of metals in hepatopancreas of the fishes were found in order of Znu003ePbu003eCuu003eHgu003eCd, while in muscles were Znu003eCru003ePbu003eMnu003eCuu003eCd. In general, the metals concentrations were significantly higher in liver samples than that in muscle samples. Based on the “pollution index of single factor”, the fishes, to one degree or another, were polluted by Pb, Cd, Cr, Cu and Zn, and pollution levels were mostly followed by Pbu003eCdu003eCru003eCuu003eZn. The indexes of Pb and Cd tested in hepatopancreas of the fishes were in a majority exceeded the national safety criteria for food in China. What’s more, it was found that the contents of the heavy metals in fishes did not vary with the trophic level which they belong to. In summary, the fishes were polluted by Pb, Cd, Cr, Cu and Zn to some extent, which indicated that hidden danger of heavy metals pollution was present in ecological environment or safety in fishery production in the area.