Abstract：
While the inclusion of synthetic polymers such as primary microplastics within personal care products have been widely restricted under EU/UK Law, water-soluble polymers (WSPs) have so far slipped the net of global chemical regulation despite evidence that these could be polluting wastewater effluents at concentrations greatly exceeding those of microplastics. Polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) represent WSPs with common industry and household uses, down-the-drain disposal and a direct route to wastewater treatment plants, conveying high risk of environmental leaching into freshwater ecosystems. The current study is the first investigating the impacts of predicted environmental concentrations of these WSPs on life-history traits of two freshwater species also constituting a disease model (fish - Poecilia reticulata and parasite - Gyrodactylus turnbulli). Single effects of WSPs on fish as well as their interactive effects with infection of the ectoparasite were determined over a 45-day exposure. Generally, WSPs reduced fish growth and increased routine metabolic rate of fish implying a depleted energetic budget, however these effects were dose, exposure time and polymer dependent. Parasitic infection alone caused a significant reduction in fish growth and enhanced fish routine metabolic rate. In contrast, a non-additive effect on metabolic rate was evident in fish experiencing simultaneous infection and WSP exposure, suggesting a protective effect of the two WSPs for fish also exposed to a metazoan ectoparasite. Off-host parasite survival was significantly lowered by both WSPs; however, parasite counts of infected fish also exposed to WSP were not significantly different from the control, implying more complex mechanisms may underpin this stressor interaction. Distinct detrimental impacts were inflicted on both organisms implying environmental leaching of WSPs may be causing significant disruption to interspecies interactions within freshwater ecosystems. Additionally, these results could contribute to sustainable development in industry, as we conclude PVA represents a less harmful alternative to PVP.
摘要：
虽然在个人护理产品中加入合成聚合物（如主要的微塑料）受到欧盟/英国法律的广泛限制，尽管有证据表明，水溶性聚合物（WSP）可能会污染废水废水，其浓度大大超过微塑料的浓度，但到目前为止，水溶性聚合物（WSP）已经滑落了全球化学法规的网。聚乙烯醇（PVA）和聚乙烯吡咯烷酮（PVP）代表具有常见的工业和家庭用途的WSP，下泄处理和通往废水处理厂的直接途径，将环境浸出的高风险传递到淡水生态系统中。当前的研究是首次调查这些WSP的预测环境浓度对两种淡水物种的生活史特征的影响，这两种淡水物种也构成了疾病模型（鱼类-网纹Poeciliareticulata和寄生虫-Gyrodactylusturnbulli）。在45天的暴露时间内，确定了WSP对鱼类的单一作用以及它们与体外寄生虫感染的相互作用作用。一般来说,WSP减少了鱼类的生长，增加了鱼类的常规代谢率，这意味着精力充沛的预算。然而这些影响是剂量，暴露时间和聚合物依赖性。仅寄生虫感染就导致鱼类生长显着降低，并提高了鱼类的常规代谢率。相比之下,在同时感染和WSP暴露的鱼类中，对代谢率的非累加效应是明显的，表明两种WSP对也暴露于后生动物外寄生虫的鱼类具有保护作用。两种WSP均显着降低了宿主外寄生虫的存活率；但是，也暴露于WSP的受感染鱼类的寄生虫计数与对照没有显着差异，暗示更复杂的机制可能是这种应激源相互作用的基础。两种生物都受到了明显的有害影响，这意味着WSP的环境浸出可能会对淡水生态系统中的种间相互作用造成重大破坏。此外,这些结果有助于工业的可持续发展，正如我们得出的结论，PVA代表了PVP的一种危害较小的替代品。
