Background

The European Water Framework Directive (WFD) requires the monitoring of biota—preferably fish—to check the compliance of tissue concentrations of priority substances (PS) against substance-specific environmental quality standards (EQSs). In monitoring programs, different fish species are covered, which often are secondary consumers with a trophic level (TL) of about 3. For harmonization, a normalization of monitoring data to a common trophic level is proposed, i.e., TL 4 (predatory fish) in freshwaters, so that data would be sufficiently protective. For normalization, the biomagnification properties of the chemicals can be considered by applying substance-specific trophic magnification factors (TMFs). Alternatively, TL-corrected biomagnification factors (BMF_TLs) may be applied. Since it is impractical to derive site-specific TMFs or BMF_TLs, often data from literature will be used for normalization. However, available literature values for TMFs and BMF_TLs are quite varying. In the present study, the use of literature-derived TMFs and BMF_TLs in data normalization is studied more closely.

Results

An extensive literature evaluation was conducted to identify appropriate TMFs for the WFD PS polybrominated diphenyl ethers (PBDE), hexachlorobenzene, perfluorooctane sulfonate (PFOS), dioxins and dioxin-like compounds (PCDD/F + dl-PCB), hexabromocyclododecane, and mercury. The TMFs eventually derived were applied to PS monitoring data sets of fish from different trophic levels (chub, bream, roach, and perch) from two German rivers. For comparison, PFOS and PBDE data were also normalized using literature-retrieved BMF_TLs.

Conclusions

The evaluation illustrates that published TMFs and BMF_TLs for WFD PS are quite variable and the selection of appropriate values for TL 4 normalization can be challenging. The normalized concentrations partly included large uncertainties when considering the range of selected TMFs, but indicated whether an EQS exceedance at TL 4 can be expected. Normalization of the fish monitoring data revealed that levels of substances accumulating in the food web (TMF or BMF > 1) can be underestimated when relying on fish with TL < 4 for EQS compliance assessment. The evaluation also revealed that TMF specifically derived for freshwater ecosystems in Europe would be advantageous. Field-derived BMF_TLs seemed to be no appropriate alternative to TMFs, because they can vary even stronger than TMFs.

中文翻译：

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根据欧洲水框架指令对优先物质的营养放大因子的选择和应用以规范淡水鱼监测数据：一个案例研究

背景

欧洲水框架指令（WFD）要求对生物群（最好是鱼类）进行监控，以检查特定物质的环境质量标准（EQS）是否符合优先物质（PS）的组织浓度要求。在监测计划中，涵盖了不同的鱼类，这些鱼类通常是营养水平（TL）约为3的次要消费者。为实现协调一致，建议将监测数据标准化为常见的营养水平，即TL 4（掠食性鱼类）在淡水中，因此数据将具有足够的保护性。为了进行标准化，可以通过应用特定于物质的营养放大倍数（TMF）来考虑化学物质的生物放大特性。或者，使用TL校正的生物放大系数（BMF _TLs）可能适用。由于派生特定于站点的TMF或BMF _TL是不切实际的，因此通常会将来自文献的数据用于归一化。但是，TMF和BMF _TL的可用文献值相差很大。在本研究中，将更加仔细地研究文献衍生的TMF和BMF _TL在数据标准化中的使用。

结果

进行了广泛的文献评估，以确定WFD PS多溴联苯醚（PBDE），六氯苯，全氟辛烷磺酸（PFOS），二恶英和二恶英样化合物（PCDD / F + dl-PCB），六溴环十二烷和汞的合适TMF。最终得出的TMF被应用于PS监测来自德国两条河流的不同营养水平（bre，，蟑螂和鲈鱼）的鱼类数据集。为了进行比较，也使用文献检索的BMF _TL对PFOS和PBDE数据进行了标准化。

结论

该评估表明，针对WFD PS的已发布TMF和BMF _TL的变化很大，并且为TL 4标准化选择合适的值可能具有挑战性。考虑所选TMF的范围时，归一化浓度部分包括较大的不确定性，但指出是否可以预期EQS超过TL 4。鱼类监测数据的标准化表明，当依赖TL <4的鱼类进行EQS符合性评估时，食物网中所积聚的物质水平（TMF或BMF> 1）可能会被低估。评估还显示，专门用于欧洲淡水生态系统的TMF是有利的。场派生的BMF _TL似乎不是TMF的合适替代品，因为它们的变化甚至可能比TMF大。