Diamond Jerry, Stribling James, Bowersox Marcus, Latimer Henry
Tetra Tech, 400 Red Brook Boulevard, Suite 200, Owings Mills, Maryland 21117, USA.
Integr Environ Assess Manag. 2008 Oct;4(4):456-70. doi: 10.1897/IEAM_2008-005.1.
The types and quality of data needed to determine relationships between chronic whole effluent toxicity (WET) test results and in-stream biological condition were evaluated using information collected over a 1.5-y period from 6 different sites across the United States. A data-quality-objectives approach was used that included several proposed measurement quality objectives (MQOs) that specified desired precision, bias, and sensitivity of methods used. The 6 facilities used in this study (4 eastern and 2 western United States) all had design effluent concentrations >60% of the stream flow. In addition to at least quarterly chronic Ceriodaphnia dubia, Pimephales promelas (fathead minnow), and Selenastrum capricornutum (green algae) WET tests, other tests were conducted to address MQOs, including splits, duplicates, and blind positive and negative controls. Macroinvertebrate, fish, and periphyton bioassessments were conducted at multiple locations upstream and downstream of each facility. The test acceptance criteria of the US Environmental Protection Agency (USEPA) were met for most WET tests; however, this study demonstrated the need to incorporate other MQOs (minimum and maximum percent significant difference and performance on blind samples) to ensure accurate interpretation of effluent toxicity. More false positives, higher toxicity, and more "failed" (noncompliant) tests were observed using no-observed-effect concentration (NOEC) as compared to the IC25 endpoint (concentration causing > or =25% decrease in organism response compared to controls). Algae tests often indicated the most effluent toxicity in this study; however, this test was most susceptible to false positives and high interlaboratory variability. Overall, WET test results exhibited few relationships with bioassessment results even when accounting for actual effluent dilution. In general, neither frequency of WET noncompliance nor magnitude of toxicity in tests were significantly related to differences in biological condition upstream and downstream of a discharge. Periphyton assessments were most able to discriminate small changes downstream of the effluent, followed by macroinvertebrates and fish. Although sampling methods were robust, more replicate samples collected upstream and downstream of each facility were needed to increase detection power. In general, macroinvertebrate and periphyton assessments together appeared to be sufficient to address project objectives.
利用在美国6个不同地点1.5年期间收集的信息，评估了确定慢性全废水毒性（WET）测试结果与河流生物状况之间关系所需的数据类型和质量。采用了数据质量目标方法，其中包括几个提议的测量质量目标（MQO），这些目标规定了所用方法的期望精度、偏差和灵敏度。本研究中使用的6个设施（美国东部4个，西部2个）的设计废水浓度均超过河流流量的60%。除了至少每季度进行一次慢性的大型蚤、黑头呆鱼和羊角月牙藻WET测试外，还进行了其他测试以满足MQO，包括分割样本、重复样本以及盲法阳性和阴性对照。在每个设施上游和下游的多个地点进行了大型无脊椎动物、鱼类和周丛生物评估。大多数WET测试符合美国环境保护局（USEPA）的测试验收标准；然而，本研究表明需要纳入其他MQO（最小和最大显著差异百分比以及对盲样的性能）以确保对废水毒性进行准确解释。与IC25终点（与对照相比导致生物反应降低≥25%的浓度）相比，使用未观察到效应浓度（NOEC）时观察到更多的假阳性、更高的毒性和更多“不合格”（不符合规定）的测试。藻类测试在本研究中常常显示出最高的废水毒性；然而，该测试最容易出现假阳性和较高的实验室间变异性。总体而言，即使考虑实际废水稀释情况，WET测试结果与生物评估结果之间的关系也很少。一般来说，WET不符合规定的频率或测试中的毒性大小与排放上游和下游生物状况的差异均无显著关系。周丛生物评估最能够区分废水下游的微小变化，其次是大型无脊椎动物和鱼类。尽管采样方法可靠，但需要在每个设施的上游和下游收集更多的重复样本以提高检测能力。一般来说，大型无脊椎动物和周丛生物评估共同似乎足以实现项目目标。
