Naddy Rami B, Stubblefield William A, May Jeffrey R, Tucker Scott A, Hockett J Russell
ENSR, Fort Collins, Colorado 80521, USA.
Environ Toxicol Chem. 2002 Feb;21(2):347-52.
While it is generally accepted that water hardness affects copper toxicity, the major ions that contribute to water hardness (calcium [Ca] and magnesium [Mg]) may affect copper toxicity differently. This is important because the Ca:Mg ratio in standard laboratory-reconstituted waters often differs from the ratio in natural surface waters. Copper toxicity was assessed for five different aquatic species: rainbow trout (RBT), fathead minnow (FHM), Ceriodaphnia dubia, Daphnia magna, and an amphipod (Gammarus sp.) under different Ca:Mg ratios (4:0, 3:1, 1:1, 1:3, and 1:4 mass basis) at a common hardness (180 mg/L as CaCO3) and alkalinity (120 mg/L as CaCO3). Copper toxicity increased at lower Ca:Mg ratios for RBT but increased at higher Ca:Mg ratios for D. magna. Fathead minnows (<24 h old) were more sensitive to copper in 1:1 Ca:Mg waters compared to 3:1 Ca:Mg waters. The toxicity of copper did not vary under different Ca:Mg ratios for Gammarus sp., C. dubia, and 28-d-old FHM. The effect of Ca:Mg ratios on copper toxicity changed for D. magna in softer water (90 mg/L as CaCO3) compared with hard water studies.
虽然人们普遍认为水的硬度会影响铜的毒性，但构成水硬度的主要离子（钙[Ca]和镁[Mg]）对铜毒性的影响可能不同。这一点很重要，因为标准实验室配制水中的钙镁比通常与天然地表水的比例不同。在常见硬度（以碳酸钙计为180毫克/升）和碱度（以碳酸钙计为120毫克/升）下，针对五种不同的水生生物评估了不同钙镁比（质量比为4:0、3:1、1:1、1:3和1:4）时的铜毒性，这五种水生生物分别是虹鳟（RBT）、黑头呆鱼（FHM）、 dubia 角突网纹溞、大型溞和一种双甲藻（Gammarus sp.）。对于虹鳟，在较低钙镁比时铜毒性增加，但对于大型溞，在较高钙镁比时铜毒性增加。与钙镁比为3:1的水相比，24小时龄以下的黑头呆鱼在钙镁比为1:1的水中对铜更敏感。对于双甲藻、dubia角突网纹溞和28日龄的黑头呆鱼，铜的毒性在不同钙镁比下没有变化。与硬水研究相比，在较软水（以碳酸钙计为90毫克/升）中，钙镁比对大型溞铜毒性的影响发生了变化。
