The Safety Evaluation of the Acute Toxicological Effects of Inorganic-Cadmium on Scapharca broughtonii

Abstract:

Heavy metals are considered as the most deleterious contaminants in the environment due to their non-degrading and bioaccumulative properties. Shellfish have been used as an indictor for the toxicity of Cd, Pb, and other heavy metals. However, there are very few studies about the effects of heavy metals on Scapharca broughtonii. The safety of the seafood largely depends on the level of heavy metals accumulated in the body, which is determined by the content of heavy metals in the aquaculture environment. Here qualitative and quantitative methods were conducted to study the acute toxicity of cadmium on S. broughtonii with different sizes, which serves as a sign of the seafood safety. We determined the semi lethal concentration (LC50) and the safety concentration (SC50) of cadmium in different time courses (24 h, 48 h, 72 h and 96 h), by SPSS18.0 statistical software (Prob-lg). The LC50 values of small S. broughtonii were 131.11, 41.40, 3.57 and 3.37 mg/L corresponding to the time courses above, and the SC50 value was 1.24 mg/L. In the medium S. broughtonii the LC50 values were 54.10, 9.46, 2.54, and 0. 50 mg/L, and the SC50 value was 0.09 mg/L. About the large S. broughtonii the LC50 values were 157.36, 38.13, 8.90, 3.46 mg/L and the SC50 value was 0.67 mg/L. These results demonstrated that the SC50 values of Cd2+ in S. broughtonii were higher than the water quality standard in aquaculture. The toxicity of Cd2+ was identified as moderate for small S. broughtonii, extreme toxicity medium S. broughtonii, and high toxicity for large S. broughtonii. There was hermetie effect on inorganrc cadmium for small S. broughtonii.