The acute toxicity and joint toxicity effect of cadmium, zinc and chromium on Culter alburnus Basilewsky larva

Heavy metal pollution is one of the most hazards of environmental pollution these years in fishery.With the development of industry and agriculture, a lot of heavy metal pollutants are released through various methods into the water body.Biological monitoring can reflect the environmental pollution conditions completely, sensitively and continuously.Culter alburnus Basilewsky is a widely exiting fish all over the whole country that with highly economic value.In order to estimate the acute toxicity and joint toxicity of heavy metal Cd²⁺,Zn²⁺ and Cr⁶⁺ toward C.alburnus Basilewsky, single chemical and mixture experiments were tested in still water at(22±1)℃.Resultsof single toxicity tests are as following: LC₅₀ of Cd²⁺ on C.alburnus in 24 h, 48 h, 72 h, 96 h were respectively 12.29,9.56,7.41 and 6.05 mg/L,LC₅₀ of Zn²⁺ were respectively 41.92,34.43,27.37 and 22.23 mg/L,LC₅₀ of Cr⁶⁺ were respectively 39.47,32.68,27.25 and 25.72 mg/L;the safety concentrations for Cd²⁺,Zn²⁺ and Cr⁶⁺ were respectively 0.605,2.223 and 2.572 mg/L.Joint toxicity experiments indicated that AI>0 of the coexistence of Cd²⁺/Zn²⁺ in 24 h, 48 h, 72 h, 96 h, as well as Zn²⁺/Cr⁶⁺ and Cd²⁺/Cr⁶⁺.Every coexistence group showed synergy.Among these groups, the joint toxicity of Zn²⁺/Cr⁶⁺ suggested the most intensive.