Background

This study aims to describe and test a tiered approach for assessing compliance to Environmental Quality standards (EQSs) for priority substances in biota in line with the European Water Framework Directive. This approach is based on caged gammarids and trophic magnification factors (TMFs) at the first tier, with fish analyzed at the second tier at sites predicted to exceed the EQS at the first tier. A dataset was implemented by monitoring perfluorooctane sulfonate (PFOS) in caged gammarids exposed at 15 sites in French rivers, and in fish muscle and rest-of-body from the same sites. Isotopic ratios (δ¹³C and δ¹⁵ N) were also measured in gammarids and fish. Two scenarios were developed to compare measured PFOS concentrations in fish against predicted concentrations based on measures in caged gammarids and TMFs. Scenario (1) compared measured PFOS concentrations in fish fillets with predicted PFOS concentrations based on measured concentrations in caged gammarids and δ¹⁵ N. Scenario (2) tested whether or not EQS exceedance was correctly predicted based on measured concentrations in caged gammarids and trophic levels (TLs) from wild fish and gammarid populations.

Results

δ¹³C and δ¹⁵ N variations showed that caged gammarids used local food resources during exposure in the field. PFOS concentrations in gammarids were fairly variable through time at each site. In fish, concentrations ranged from < 1 to 250 ng g⁻¹ (wet weight). After adjustment to the TL at which the EQS is set, 12 sites were above the EQS for PFOS. In scenario (1), predicted concentrations were almost correct at 7 sites out of 15. Most incorrect predictions were overestimations that were slightly improved by applying a lower (neutral) TMF. In scenario (2) we tested several variants for parameters involved in the predictions. The most efficient combination yielded two wrong predictions out of 15. This result was obtained with a higher (more conservative) TMF value, mean concentrations in gammarids from several field exposures during a year, and a TL for gammarids at the median of the distribution in French rivers.

Conclusion

The proposed tiered approach was thus efficient. However, the number of sites was relatively limited, and the dataset was biased towards EQS exceedance. The tiered approach warrants further validation.

中文翻译：

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根据《水框架指令》监测生物群中的优先物质：基于笼中无脊椎动物的分层方法效果如何？针对法国河流中全氟辛烷磺酸的概念验证研究

背景

这项研究旨在描述和测试一种分层方法，用于评估根据欧洲水框架指令对生物群中优先物质的环境质量标准（EQS）的合规性。这种方法基于第一层的笼状γ-射线和营养放大因子（TMF），第二层的鱼类分析预计将超过第一层的EQS。通过监测法国河流中15个地点暴露的笼状γ-甲酰胺，以及相同地点的鱼肌肉和身体其余部位中的全氟辛烷磺酸（PFOS）来实现数据集。同位素比率（δ ¹³ C和δ ¹⁵ N）也在γ-线虫和鱼类中测量。开发了两种方案，根据笼中伽马鱼和TMF中的测量值将鱼中的全氟辛烷磺酸浓度与预测的浓度进行比较。方案（1）相比较测得的全氟辛烷磺酸的浓度在鱼片与基于在笼gammarids和δ测量的浓度预测PFOS浓度¹⁵  N.情形（2）测试是否EQS超标被正确预测基于在笼gammarids和营养水平测量的浓度（TLs）来自野生鱼类和伽马虫种群。

结果

δ ¹³ C和δ ^15个 Ñ变化表明，笼gammarids场曝光期间所使用的本地食物资源。每个地点的γ-全氟辛烷磺酸浓度随时间变化很大。在鱼类中，浓度范围<1至250 ng g ^-1（湿重）。调整了设置EQS的TL后，PFOS的EQS上方有12个站点。在场景（1）中，在15个位置中的7个位置的预测浓度几乎是正确的，大多数不正确的预测是高估，通过应用较低的（中性）TMF可以稍微改善这一点。在场景（2）中，我们针对预测中涉及的参数测试了几种变体。最有效的组合产生了15个错误的两个预测结果。获得此结果的原因是更高的TMF值（更保守），一年中几次野外暴露的γ-射线平均浓度以及γ-射线分布中值的TL值。法国河流。

结论

因此，建议的分层方法非常有效。但是，站点数量相对有限，并且数据集偏向于超出EQS。分层方法需要进一步验证。