Per- and polyfluoroalkyl substances (PFAS) are an important class of emerging contaminants in the environment. Most studies on the impact of PFAS mixtures considered phenotypic endpoints, which may not adequately reflect the sublethal effects on organisms. To fill this knowledge gap, we investigated the subchronic impact of environmentally relevant concentrations of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)—as individual compounds and a mixture (PFOS+PFOA)—on earthworm (Eisenia fetida), using phenotypic and molecular endpoints. PFAS decreased the survival (12.2–16.3%), biomass (9.0–9.8%), and reproduction (15.6–19.8%) of E. fetida after 28 d of exposure. The bioaccumulation of PFOS after 28 d increased (from 2790.7 ng/g-dw to 5224.9 ng/g-dw) while that of PFOA decreased (from 780.2 ng/g-dw to 280.5 ng/g-dw) when E. fetida was exposed to the mixture compared to the individual compounds. These bioaccumulation trends were partly attributed to changes in the soil distribution coefficient (K_d) of PFOS and PFOA when present in the mixture. Eighty percent of the (p and FDR < 0.05) altered metabolites after 28 d were similarly perturbed by both PFOA and PFOS+PFOA. The pathways dysregulated are related to the metabolism of amino acids, energy, and sulfur. We showed that PFOA dominates the molecular-level impact of the binary PFAS mixture.

全氟烷基物质和多氟烷基物质 (PFAS) 是环境中一类重要的新兴污染物。大多数关于 PFAS 混合物影响的研究都考虑了表型终点，这可能无法充分反映对生物体的亚致死影响。为了填补这一知识空白，我们利用表型研究了环境相关浓度的全氟辛酸 (PFOA) 和全氟辛烷磺酸 (PFOS)（单独化合物和混合物 (PFOS+PFOA)）对蚯蚓 ( Eisenia fetida ) 的亚慢性影响。和分子终点。PFAS 降低了臭艾球菌的存活率 (12.2–16.3%)、生物量 (9.0–9.8%) 和繁殖率 (15.6–19.8%)暴露28天后。28天后，当恶臭艾美球菌被处理后，PFOS的生物累积量增加（从2790.7 ng/g-dw到5224.9 ng/g-dw），而PFOA的生物累积量则下降（从780.2 ng/g-dw到280.5 ng/g-dw）。与单独的化合物相比，暴露于混合物中。这些生物累积趋势部分归因于混合物中存在的 PFOS 和 PFOA 的土壤分配系数 ( K _{d ) 的变化。}28 天后， 80%（p和 FDR < 0.05）改变的代谢物同样受到 PFOA 和 PFOS+PFOA 的干扰。失调的途径与氨基酸、能量和硫的代谢有关。我们表明，PFOA 在二元 PFAS 混合物的分子水平影响中占主导地位。