Crossland N O
Biology Department, University of Mississippi, Oxford.
Toxicol Lett. 1992 Dec;64-65 Spec No:511-7. doi: 10.1016/0378-4274(92)90226-a.
Hazard assessment of chemicals in freshwater environments depends on comparing concentrations that are expected to occur in water and sediment, i.e. expected environmental concentrations (EEC), with those that are estimated to have no biological effects, i.e. the no-observed effect concentrations (NOEC). The difference between these two estimates is the margin of safety. The EEC can be estimated from data for chemical release rates, physicochemical properties and environmental parameters that affect transport and transformation. The NOEC can be estimated from the results of toxicity tests using aquatic plants, invertebrates and fish. When making these estimates it may be necessary to extrapolate from relatively limited laboratory data to the real world. Inevitably, this involves some degree of uncertainty. Such uncertainty can often be resolved by carrying out controlled field tests, using small, outdoor enclosures (microcosms), relatively large, outdoor ponds (mesocosms) and experimental streams. In this paper the advantages and disadvantages of various experimental approaches and systems will be reviewed.
淡水环境中化学物质的危害评估取决于将预计在水和沉积物中出现的浓度，即预期环境浓度（EEC），与估计不会产生生物效应的浓度，即无观测效应浓度（NOEC）进行比较。这两个估计值之间的差异就是安全边际。EEC可以根据化学物质释放速率、物理化学性质以及影响迁移和转化的环境参数数据来估计。NOEC可以根据使用水生植物、无脊椎动物和鱼类进行的毒性测试结果来估计。在进行这些估计时，可能需要从相对有限的实验室数据推断到现实世界。不可避免地，这涉及到一定程度的不确定性。这种不确定性通常可以通过进行受控的现场测试来解决，这些测试使用小型户外围隔（微观世界）、相对较大的户外池塘（中观世界）和实验溪流。本文将综述各种实验方法和系统的优缺点。
