Toxic Effects Of LAS, Cd(Ⅱ) Single And Combined Pollution On Carassius Auratus

With the development of agriculture and industry, much of contamination including Cd²⁺ and LAS was discharged into water system, which seriously endangered the growth and survival of aquatic animals. To investigate the effects of linear alkylbenzene sulphonates (LAS) and Cd(â…¡) single and combined pollution in Carassius auratus,the acute toxicity and joint toxicity tests of LAS,Cd(â…¡), Cd accumulation and the activities of enzymes including superoxide dismutas(SOD), catalase(CAT), Na⁺-K⁺-ATPase and acetylcholinesterase(AChE) were measured in Carassius auratus tissues under the reproductive toxicities of LAS and Cd²⁺ single or in their combinations by using exposed experiment. The main contents and results were summarized as the following:1. The acute toxicity and joint toxicity tests of LAS and Cd(â…¡) to Carassius auratusThe results showed that the LC₅₀ of 24h, 48h, 72h and 96h for LAS to Carassius auratus were 24.73, 19.83, 18.78 and 16.96 mg.L^-1 respectivly, and the LC₅₀ of 48h, 72h and 96h for Cd²⁺ were 10.26, 8.72 and 6.85 mg.L^-1 respectivly. The toxicity of Cd²⁺ was higher than that of the LAS. In addition, it also indicated that the joint toxicity of Cd²⁺ and LAS was synergistic while the toxicity was 1: 1 at 24h, 48h, 72h and 96 h by evaluation using marking additive index.2. The effects of LAS,Cd(â…¡) single and combined pollution on Cd accumulation in Carassius auratus tissuesCd accumulation in the tissues of Carassius auratus including gill , liver, brain, ovary and muscle were studied in concentrations of LAS (1.0 mg.L^-1, 5.0 mg.L^-1) and Cd²⁺(0.4 mg.L^-1, 2.0 mg.L^-1) stressed for 14 days by using exposed experiment. The results indicated that Cd²⁺ single exposure induced its accumulation significantly in all these five tissues with the sequence of liver >gill>brain>ovary>muscle. Meanwhile, the combined effects of Cd²⁺ and LAS exhibited a similar pattern in Cd accumulation compared with the Cd²⁺ single exposure in these tissues but different in concentration. 0.4 mg.L^-1 Cd²⁺ and 1.0 mg.L^-1 LAS induced higher Cd concentration in gill and brain, and 0.4 mg.L^-1 Cd²⁺ and 5.0 mg.L^-1 LAS induced higher Cd concentration in liver and ovary, similarly, the combination of 2.0 mg.L^-1 Cd²⁺ and all the levels of LAS induced higher Cd concentration in liver and muscle but decreased in brain, further, 2.0 mg.L^-1 Cd²⁺and 5.0 mg.L^-1 LAS increased higher Cd concentration in gill and ovary, as compared with the Cd²⁺ single exposure.3. The effects of LAS,Cd(â…¡) single and combined pollution on the activities of SOD,CAT and Na⁺-K⁺-ATPase in the gill and liver tissues of Carassius auratusThe results showed that the dose-effect was observed under singlepollution both in the liver and gill compared with control. Different pollution combined treatments produced different effects in changes of three enzymes activities in the liver and gill. Thus, 0.4 mg.L^-1 Cd²⁺ induced the SOD, CAT and Na⁺-K⁺-ATPase activities decreased with increase of LAS concentration, and the SOD, Na⁺-K⁺-ATPase activities in the liver and CAT activity in the gill were lower under combined stress than that of Cd²⁺ single treatment significantly, while, 2.0 mg.L^-1 Cd²⁺ and 5.0 mg.L^-1 LAS induced the SOD and Na⁺-K⁺-ATPase activities in the gill and the SOD activity in the liver decreased significantly compared with the Cd²⁺ or LAS single treatment. Finally, it can be concluded that the joint effects of the combined pollution on the SOD and Na⁺-K⁺-ATPase activities were synergistic under certain LAS and Cd²⁺ concentration4. The effects of LAS,Cd(â…¡) single and combined pollution on the activities of AChE in the brain of Carassius auratusThe results indicated that the AChE activity in the brain tissues was inhibited significantly with increase of concentrations under LAS or Cd²⁺ single exposure. LAS and Cd²⁺ combined treatments induced the AChE activity inhibited significantly compared with the Cd²⁺ or LAS single exposure. The joint effects of the combined pollution on the AChE activity was obviously synergistic, and different pollution combined treatments in LAS and Cd²⁺ concentrations produced different effects in changes of the AChE activity.