The continuously growing plastic production and incomplete recycling processes open manifold entry routes for microplastic particles (MPs) into the environment. Since knowledge on trophic transfer of contaminants sorbed to MPs is still insufficient for freshwater systems, the transfer of the model pollutant benzo(k)fluoranthene (BkF) sorbed to polymethyl methacrylate (PMMA) particles in a limnic food web was investigated: Two freshwater invertebrates (Daphnia magna and Chironomus riparius larvae) were selected and either left untreated, exposed to pristine PMMA, PMMA-associated BkF, or exposed to dissolved BkF (BkF_aq). As second-level consumers, zebrafish (Danio rerio) were fed twice daily with pre-treated invertebrates over two days. Induction of hepatic cytochrome P450 by BkF was determined as 7-ethoxy-O-resorufin deethylase (EROD) activity. Both invertebrate species readily ingested PMMA particles, tracked via fluorescence microscopy and accumulated BkF_aq, measured via GC–MS. Fluorescence signals in gastrointestinal tracts of zebrafish were quantified with confocal laser scanning microscopy (CLSM). The fluorescence signal in gastrointestinal tracts of zebrafish was not altered, whereas, EROD activity was significantly induced when zebrafish were fed with Chironomus riparius, pre-exposed to BkF_aq. Trophic exposure scenarios with BkF sorbed to PMMA did not result in any alterations of investigated endpoints in both invertebrate species and zebrafish compared to controls. Given that BkF amounts were in the low ng-range, as detected by GC–MS, the transport of MP-sorbed BkF to zebrafish was less effective than direct exposure to waterborne BkF_aq, and the potential threat of trophic transfer of substances such as BkF in limnic food webs may have been overestimated.

不断增长的塑料生产和不完全的回收过程为微塑料颗粒（MP）进入环境打开了多种途径。由于对于淡水系统而言，关于吸附到MPs上的污染物的营养传递的知识仍然不足，因此，研究了将模型污染物苯并（k）荧蒽（BkF）吸附到床food食物网中的聚甲基丙烯酸甲酯（PMMA）颗粒上的过程：两个淡水无脊椎动物选择（Daphnia magna和Chironomus riparius幼虫），不进行处理，使其暴露于原始的PMMA，与PMMA相关的BkF，或暴露于溶解的BkF（BkF _aq）。作为二级消费者，斑马鱼（Danio rerio）在两天内每天喂食两次经过预处理的无脊椎动物。BkF对肝细胞色素P450的诱导被确定为7-乙氧基-O-试卤灵脱乙基酶（EROD）活性。两种无脊椎动物都容易摄入PMMA颗粒，通过荧光显微镜对其进行跟踪，并通过GC-MS测定其积累的BkF _aq。用共聚焦激光扫描显微镜（CLSM）量化斑马鱼胃肠道中的荧光信号。斑马鱼胃肠道中的荧光信号没有改变，而当斑马鱼喂食预先暴露于BkF _aq的河豚Chironomus riparius时，EROD活性被明显诱导。。与对照组相比，BkF吸附在PMMA上的营养暴露情况并未导致无脊椎动物和斑马鱼的研究终点发生任何变化。气相色谱-质谱法检测到，鉴于BkF的量处于低ng范围内，MP吸附的BkF向斑马鱼的运输要比直接暴露于水性BkF _aq的效率低，并且可能对诸如亚麻食物网中的BkF可能被高估了。