Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, China.
J Hazard Mater. 2024 Oct 5;478:135515. doi: 10.1016/j.jhazmat.2024.135515. Epub 2024 Aug 13.
The behavior and fate of PFOS (perfluorooctanesulfonate) in the aquatic environment have received great attention due to its high toxicity and persistence. The nanoscale supramolecular mechanisms of interaction between PFOS and ubiquitous EPS (exopolymers) remain unclear though EPS have been widely-known to influence the bioavailability of PFOS. Typically, the exposure patterns of PFOS in aquatic animals changed with the EPS-PFOS interaction are not fully understood. This study hypothesized that PFOS exposure and accumulation pathways depended on the PFOS-EPS interactive assembly behavior and animal species. Two model animals, zebrafish and chironomid larvae, with different feeding habitats were chosen for the exposure and accumulation tests at the environmental concentrations of PFOS in the absence and presence of EPS. It was found that PFOS triggered the self-assembly of EPS to form large aggregates which significantly trapped PFOS. PFOS accumulation was significantly promoted in zebrafish but drastically reduced in chironomid larvae because of the nanoscale interactive assembly between EPS and PFOS. The decreased dermal uptake but increased oral uptake of PFOS by zebrafish with large mouthpart size could be ascribed to the increased ingestion of PFOS-enriched EPS aggregates as food. For the chironomid larvae with small mouthpart size, the PFOS-EPS assemblies reduced the dermal, oral and intestinal uptake of PFOS. The nano-visualization evidences confirmed that the PFOS-enriched EPS-PFOS assemblies blocked PFOS penetration through skin of both animals. These findings provide novel knowledge about the ecological risk of PFOS in aquatic environments.
全氟辛烷磺酸（PFOS）因其高毒性和持久性，其在水生态环境中的行为和归宿受到了广泛关注。尽管 EPS（胞外聚合物）已被广泛认为会影响 PFOS 的生物利用度，但 PFOS 与普遍存在的 EPS 之间的纳米级超分子相互作用机制仍不清楚。通常，水生动物中 PFOS 的暴露模式随 EPS-PFOS 相互作用而变化，但这种变化并不完全清楚。本研究假设 PFOS 的暴露和积累途径取决于 PFOS-EPS 相互作用的组装行为和动物种类。选择了两种具有不同摄食习性的模式动物（斑马鱼和摇蚊幼虫），在环境浓度的 PFOS 存在和不存在 EPS 的情况下进行暴露和积累测试。结果发现，PFOS 触发 EPS 自组装形成大的聚集体，从而显著捕获 PFOS。PFOS 在斑马鱼中的积累显著增加，但在摇蚊幼虫中却急剧减少，这是由于 EPS 和 PFOS 之间的纳米级相互作用组装所致。由于大嘴部大小的斑马鱼摄入富含 PFOS 的 EPS 聚集体作为食物，其皮肤对 PFOS 的摄取减少，但口服摄取增加。对于小嘴部大小的摇蚊幼虫，PFOS-EPS 组装减少了 PFOS 的皮肤、口服和肠道摄取。纳米可视化证据证实，富含 PFOS 的 EPS-PFOS 组装阻止了 PFOS 穿透两种动物的皮肤。这些发现为水生环境中 PFOS 的生态风险提供了新的认识。
