Levels of Toxic Elements in Fish from Fishing Ground Using Geothermal Water in Guanzhong Basin, China

Abstract

Levels of toxic elements in fish from fishing ground using geothermal water in Guanzhong Basin, China were investigated. Six elements including elements cadmium (Cd), arsenic (As), copper (Cu), fluorine (F), lead (Pb) and chromium (Cr) in fish were emphatically assessed because they were limited by safety requirements for non-environmental pollution aquatic products (GB/T18407.4-2001). Element F, Cr，Cu，As，Cd and Pb concentrations in fish muscle were in the range of 4.3-18.2 mg/kg wet weight (ww), 0.21-1.53 mg/kg ww, 2.34-2.92 mg/kg ww, nd-0.08 mg/kg ww, 0.01-0.13 mg/kg ww and 0.05-1.99 mg/kg ww, respectively. Element F concentration in each fish muscle was higher than its tolerance limit (2.0 mg/kg ww). Element Cd concentration in Tilapia muscle from Beida fishing ground exceeded its limit value (0.1 mg/kg ww). Tilapia muscle from Tezhong and Beida fishing grounds and Ctenopharyngodon idella muscle from Heyang and Changda fishing ground contained more than the safe limit of Pb (0.5 mg/kg).The bioconcentration factor (BCF) of 6 elements for fish muscle of ctenopharyngodon idella from Heyang and Changda fishing grounds were calculated. The results suggested that using geothermal heat for fish breeding may lower BCF of F and Cr but enhance bioaccumulation of Cu, As, Cd and Pb in fish muscle, which may increase health risk.