Center for Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
Integr Environ Assess Manag. 2013 Jan;9(1):63-9. doi: 10.1002/ieam.1326. Epub 2012 Sep 18.
Biotic ligand models (BLMs) have been broadly accepted and used in ecological risk assessment of heavy metals for toxicity normalization with respect to water chemistry. However, the importance of assessing bioavailability by using BLMs has not been widely recognized among Japanese stakeholders. Failing to consider bioavailability may result in less effective risk management than would be possible if currently available state-of-the-art methods were used to relate bioavailable concentrations to toxic effects. In this study, an ecological risk assessment was conducted using BLMs for 6 rivers in Tokyo to stimulate discussion about bioavailability of heavy metals and the use of BLMs in ecological risk management in Japan. In the risk analysis, a Bayesian approach was used to take advantage of information from previous analyses and to calculate uncertainties in the estimation of risk. Risks were judged to be a concern if the predicted environmental concentration exceeded the 5th percentile concentration (HC5) of the species sensitivity distribution. Based on this criterion, risks to stream biota from exposure to Cu were judged not to be very severe, but it would be desirable to conduct further monitoring and field surveys to determine whether temporary exposure to concentrations exceeding the HC5 causes any irreversible effects on the river ecosystem. The risk of exposure to Ni was a concern at only 1 of the 6 sites. BLM corrections affected these conclusions in the case of Cu but were moot in the case of Ni. The use of BLMs in risk assessment calculations for Japanese rivers requires water quality information that is, unfortunately, not always available.
生物配体模型 (BLMs) 在重金属的生态风险评估中被广泛接受和使用，用于对水化学进行毒性归一化。然而，在日本利益相关者中，评估生物可利用性的重要性并没有得到广泛认可。如果不考虑生物利用度，可能会导致风险管理效果不如使用当前可用的最先进方法将生物有效浓度与毒性效应联系起来那么有效。在这项研究中，使用 BLMs 对东京的 6 条河流进行了生态风险评估，以激发关于重金属生物利用度和 BLMs 在日本生态风险管理中的应用的讨论。在风险分析中，采用贝叶斯方法利用来自先前分析的信息，并计算风险估计的不确定性。如果预测的环境浓度超过物种敏感性分布的第 5 百分位数浓度 (HC5)，则认为风险令人担忧。根据这一标准，溪流生物群暴露于 Cu 所带来的风险被认为不是很严重，但最好进行进一步的监测和现场调查，以确定临时暴露于超过 HC5 的浓度是否会对河流生态系统造成任何不可逆的影响。在 6 个地点中，只有 1 个地点的 Ni 暴露风险令人担忧。BLM 修正对 Cu 的结论有影响，但对 Ni 的结论没有影响。在日本河流的风险评估计算中使用 BLMs 需要水质信息，但不幸的是，这些信息并不总是可用。
