State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Xianlin Campus, Nanjing University, Nanjing 210023, Jiangsu, PR China.
Ecotoxicol Environ Saf. 2013 Sep;95:83-90. doi: 10.1016/j.ecoenv.2013.05.020. Epub 2013 Jun 12.
This study investigated the effect of pH on cadmium toxicity to three aquatic organisms: Photobacterium phosphoreum, Daphnia magna and Carassius auratus. The acute toxicity of Cd(2+) to P. phosphoreum and D. magna at five pH values (5.0, 6.0, 7.0, 8.0, and 9.0) was assessed by calculating EC50 values. We determined that Cd(2+) was least toxic under acidic conditions, and D. magna was more sensitive to the toxicity of Cd than P. phosphoreum. To evaluate Cd(2+)-induced hepatic oxidative stress in C. auratus at three pH levels (5.0, 7.25, 9.0), the activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), the level of glutathione and the malondialdehyde content in the liver were measured. Oxidative damage was observed after 7d Cd exposure at pH 9.0. An important finding of the current research was that Cd(2+) was generally more toxic to the three test organisms in alkaline environments than in acidic environments.
本研究探讨了 pH 值对三种水生生物（发光菌、大型溞和金鱼）镉毒性的影响。通过计算 EC50 值评估了 Cd(2+) 在五个 pH 值（5.0、6.0、7.0、8.0 和 9.0）下对 P. phosphoreum 和 D. magna 的急性毒性。结果表明，Cd(2+) 在酸性条件下毒性最小，而 D. magna 对 Cd 的毒性比 P. phosphoreum 更敏感。为了评估 Cd(2+) 在三个 pH 值（5.0、7.25、9.0）下对金鱼肝脏的氧化应激，测定了抗氧化酶（超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶）的活性、谷胱甘肽水平和肝组织丙二醛含量。在 pH 9.0 下 Cd 暴露 7d 后观察到氧化损伤。本研究的一个重要发现是，Cd(2+) 在碱性环境下通常比在酸性环境下对三种受试生物的毒性更大。
