Long Kristen E, Van Genderen Eric J, Klaine Stephen J
Clemson University, Clemson Institute of Environmental Toxicology, Pendleton, South Carolina 29670, USA.
Environ Toxicol Chem. 2004 Jan;23(1):72-5. doi: 10.1897/02-486.
The majority of metal toxicity data available for freshwater organisms have been generated in laboratory water at pH > 6.5 and hardness > 50 mg/L as CaCO3. Extrapolation of these results to soft surface waters (i.e., hardness < or = 40 mg/L as CaCO3), similar to predominant conditions in the southeastern United States, may prove challenging. For example, South Carolina has surface waters that average 20 mg/L as CaCO3, and exist at extremes of 1 and 600 mg/L as CaCO3. This research characterized the acute toxicity of Cu to Daphnia magna in waters with low hardness and low pH. The 48-h total Cu median lethal concentrations were related to water hardness over a hardness range of 8 to 51 mg/L as CaCO3. Although toxicological differences existed between water hardness of 7 and 20 mg/L as CaCO3 (p = 0.0001), differences in pH (range 5.5-8.5) did not influence acute Cu toxicity. Results of these laboratory studies will provide the data needed to more accurately predict organism response to Cu in waters with low pH and low hardness.
现有的大多数关于淡水生物的金属毒性数据是在pH值大于6.5且硬度大于50毫克/升（以碳酸钙计）的实验室用水中得出的。将这些结果外推至软地表水（即硬度小于或等于40毫克/升，以碳酸钙计），类似于美国东南部的主要情况，可能具有挑战性。例如，南卡罗来纳州的地表水平均硬度为20毫克/升（以碳酸钙计），极端情况下为1毫克/升和600毫克/升（以碳酸钙计）。本研究描述了在低硬度和低pH值水体中铜对大型溞的急性毒性。在硬度范围为8至51毫克/升（以碳酸钙计）时，48小时总铜半数致死浓度与水硬度相关。虽然硬度为7毫克/升和20毫克/升（以碳酸钙计）的水体之间存在毒理学差异（p = 0.0001），但pH值范围（5.5 - 8.5）的差异并未影响铜的急性毒性。这些实验室研究结果将提供更准确预测低pH值和低硬度水体中生物对铜反应所需的数据。
