Pillard David A, DuFresne Doree L, Mickley Mike C
ENSR, Fort Collins, Colorado 80521, USA.
Environ Toxicol Chem. 2002 Oct;21(10):2131-7.
The concentration and balance of major ions that comprise total dissolved solids (TDS) can influence the toxicity of effluents discharged to freshwater and marine environments. An additional complicating factor in waters released to saltwater systems is the effluent salinity since the toxicity of major ions changes with the salinity of the test solution. A study was conducted to evaluate the toxicity of six major seawater ions (bicarbonate, borate, calcium, magnesium, potassium, and sulfate) to the mysid shrimp, Americamysis bahia, at salinities of 10 and 20/1000. Logistic regression models were developed to predict organism survival at deficient and excess concentrations of the ions. Calcium and potassium caused significant mortality to mysid shrimp in both excess and deficient (relative to artificial seawater) solutions. Bicarbonate, borate, and magnesium displayed significant toxicity only in excess concentrations, while sulfate had no adverse impacts at any of the concentrations tested. As the salinity of the test solutions decreased, mysid shrimp tolerated increasingly lower calcium and potassium concentrations. Similarly, as salinity increased, the upper tolerance levels of calcium, potassium, and magnesium also increased. The models developed during these studies, and similar models developed by other researchers, were used to evaluate 11 actual effluents with unexplained toxicity that might be associated with TDS ions. The models correctly identified calcium as the primary toxicant in 9 of the 11 effluents. These results indicate the models can be used as an important tool to identify toxicity associated with major seawater ions.
构成总溶解固体（TDS）的主要离子的浓度和平衡会影响排放到淡水和海洋环境中的废水的毒性。排放到咸水系统的水体中，另一个复杂因素是废水盐度，因为主要离子的毒性会随测试溶液的盐度而变化。开展了一项研究，以评估六种主要海水离子（碳酸氢根、硼酸根、钙、镁、钾和硫酸根）在盐度为10和20‰时对海湾美虾的毒性。建立了逻辑回归模型，以预测离子浓度不足和过高时的生物存活率。钙和钾在过高和不足（相对于人工海水）浓度的溶液中均对海湾美虾造成显著死亡。碳酸氢根、硼酸根和镁仅在浓度过高时显示出显著毒性，而硫酸根在任何测试浓度下均无不利影响。随着测试溶液盐度降低，海湾美虾对钙和钾浓度的耐受度越来越低。同样，随着盐度增加，钙、钾和镁的耐受上限也会增加。在这些研究中建立的模型，以及其他研究人员建立的类似模型，被用于评估11种具有无法解释的毒性且可能与TDS离子有关的实际废水。这些模型在11种废水中的9种中正确地将钙识别为主要毒物。这些结果表明，这些模型可作为识别与主要海水离子相关毒性的重要工具。
