Wageningen Environmental Research, Wageningen University and Research, P.O. Box 47, 6700, AA Wageningen, the Netherlands.
Wageningen Environmental Research, Wageningen University and Research, P.O. Box 47, 6700, AA Wageningen, the Netherlands; Current Address: Department of Biology, University of Aveiro, 3810-193, Aveiro, Portugal.
Ecotoxicol Environ Saf. 2020 Jun 1;195:110504. doi: 10.1016/j.ecoenv.2020.110504. Epub 2020 Mar 25.
28-Day sediment-spiked laboratory toxicity tests with eight benthic macroinvertebrates and the lipophilic fungicide fludioxonil were conducted to verify the proposed tiered sediment effect assessment procedure as recommended by the European Food Safety Authority (EFSA). The test species were the oligochaetes Lumbriculus variegatus and Tubifex tubifex, the insects Chironomus riparius and Caenis horaria, the crustaceans Hyalella azteca and Asellus aquaticus and the bivalves Corbicula fluminalis and Pisidium amnicum. Toxicity estimates were expressed in terms of total concentration of dry sediment as well as in pore water concentration. Field-collected sediment, also used in a previously performed sediment-spiked microcosm experiment, was used in tests with all species. L. variegatus and C. riparius had similar lowest 28d-L(E)C values when expressed in terms of total sediment concentration, but in terms of pore water concentration L. variegatus was more sensitive. Three of the six additional benthic test species (A. aquaticus, C. horaria, C. fluminalis) had 28d-EC values a factor of 2-6 lower than that of L. variegatus. Comparing different effect assessment tiers for sediment organisms, i.e. Tier-0 (Modified Equilibrium Partitioning approach), Tier-1 (Standard Test Species approach), Tier-2 (Species Sensitivity Distribution (SSD) approach) and Tier-3 (Model Ecosystem approach), it is concluded that the tiers based on sediment-spiked laboratory toxicity tests provide sufficient protection when compared with the Tier-3 Regulatory Acceptable Concentration (RAC). Differences between Tier-1 and Tier-2 RACs, however, appear to be relatively small and not always consistent, irrespective of expressing the RAC in terms of total sediment or pore water concentration. Derivation of RACs by means of the SSD approach may be a challenge, because it is difficult obtaining a sufficient number of valid chronic EC values with appropriate 95% confidence bands for sediment-dwelling macroinvertebrates. Therefore, this paper proposes a Tier-2 Weight-of-Evidence approach to be used in case an insufficient number of valid additional toxicity data is made available. Similar studies with pesticides that differ in fate properties and toxic mode-of-action are necessary for further validation of the tiered effect assessment approach for sediment organisms.
28 天的底栖大型无脊椎动物和脂溶性杀真菌剂氟啶胺的沉积物加标实验室毒性测试，以验证欧洲食品安全局 (EFSA) 建议的分层沉积物效应评估程序。测试物种包括寡毛纲环节动物（Lumbriculus variegatus 和 Tubifex tubifex）、昆虫（Chironomus riparius 和 Caenis horaria）、甲壳纲动物（Hyalella azteca 和 Asellus aquaticus）和双壳纲动物（Corbicula fluminalis 和 Pisidium amnicum）。毒性估计值以干沉积物的总浓度和孔隙水浓度表示。在所有物种的测试中，使用了现场采集的沉积物，该沉积物也用于之前进行的沉积物加标微宇宙实验。当以总沉积物浓度表示时，L. variegatus 和 C. riparius 的最低 28d-L(E)C 值相似，但以孔隙水浓度表示时，L. variegatus 更为敏感。在另外 6 种底栖测试物种中（A. aquaticus、C. horaria、C. fluminalis），有 3 种的 28d-EC 值比 L. variegatus 低 2-6 倍。比较沉积物生物的不同效应评估层次，即 Tier-0（改良平衡分配方法）、Tier-1（标准测试物种方法）、Tier-2（物种敏感性分布 (SSD) 方法）和 Tier-3（模型生态系统方法），可以得出结论，与 Tier-3 监管可接受浓度 (RAC) 相比，基于沉积物加标实验室毒性测试的层次提供了足够的保护。然而，Tier-1 和 Tier-2 RAC 之间的差异似乎相对较小，并不总是一致，无论以总沉积物还是孔隙水浓度表示 RAC 都是如此。通过 SSD 方法推导 RAC 可能具有挑战性，因为很难获得足够数量的具有适当 95%置信区间的有效慢性 EC 值，用于生活在沉积物中的大型无脊椎动物。因此，本文提出了一种 Tier-2 证据权重方法，以便在无法获得足够数量的有效额外毒性数据时使用。需要对具有不同归宿特性和毒性作用模式的农药进行类似的研究，以进一步验证沉积物生物的分层效应评估方法。
