METABOLISM: accelerator Mass SpEctrometry to quanTify nanoplastics and decipher their fAte and Behavior in envirOnmentaL and bIological SysteMs

调查纳米塑料(NPs)对水生生物影响的研究使用的浓度比公开海洋中预测的浓度高2至7个数量级，以便能够追踪NPs。这些研究将社区分为两类：一类是因观察到的生态毒理效应而发出警报的人，另一类是预测环境中NP浓度远低于任何阈值效应的人。事实上，大多数实验的设计都不充分，因此结果并不令人满意。由于缺乏合适的NP模型、跟踪方法和环境现实浓度的监测策略，符合目的的实验设计一直受到阻碍。使用14C标记的NPs和传统的核技术，我们最近模拟了扇贝，长期暴露于环境现实NP浓度(15ug/L)可能会在身体组织中积累并达到NPs浓度，响起警报的人已经观察到了影响。令人惊讶的是，这表明NPs可能已经超过了对生物的影响和对海洋生物的危害。在这里，我们将提供一种创新的方法，它将克服在现实环境中检测、测绘和量化NPs的分析限制。通过将14C标记的NPs与加速器质谱仪(AMS)的最终灵敏度相结合，新陈代谢将允许调查海洋中的NPs是否已经超过组织中的“阈值效应”浓度。新陈代谢将：i)提供具有代表性的固有放射性标记NP模型；ii)在环境现实NP浓度(ppt水平)下与模型生物(即贻贝)进行NP慢性暴露；iii)开发燃烧AMS以产生毒物动力学数据；iv)探索LA-AMS以产生空间分辨率14C测量以量化NPs的组织分布。这对于制定有关塑料垃圾的适当管理战略至关重要。如果成功，新陈代谢确实将支持政策制定者改善对NPs和其他新出现问题的污染物(CEC)的环境风险评估。据设想，这里提出的方法将使CEC的研究发生阶段性变化，并将允许研究其命运的许多不同方面(例如，转化、碎裂、生物矿化、生物分布)。新陈代谢选择了一种高度创新的方法来解决其研究问题。它结合了放射化学和解锁AMS的力量，以解决重要的环境问题。它将建立14C标记的NPs作为执行现实的基于实验室的研究的黄金标准。基础研究将产生超出其总体目标的关键影响。例如，拟议的研究将对在生物医学研究(即微量剂量)中使用14C作为低水平示踪剂产生巨大影响，而在生物医学研究中往往缺少适当的方法。提出的方法是独一无二的，将允许进行超出最先进水平的开创性科学。新陈代谢建立了一个跨学科的研究团队，整合了环境分析化学、放射化学和物理学的相关专业知识。

Studies investigating the effects of nanoplastics (NPs) on aquatic organisms used concentrations between 2 to 7 order-of-magnitudes higher than those predicted in the open ocean in order to be able to track NPs. These studies divided the community between those sounding the alarm due to the observed ecotoxicological effects, and those predicting that NP concentrations in the environment are far below any threshold-effect. In reality most experiments were inadequately designed, and thus the results unsatisfying. Fit-to-purpose experimental designs have been hindered by a lack of appropriate NP models, tracking methods, and monitoring strategies for environmentally realistic concentrations.Using 14C-labelled NPs and conventional nuclear techniques, we have recently modelled that scallops, chronically exposed (over a year) to environmentally realistic NP concentrations (15 ug/L) might accumulate and reach NPs concentrations in body tissue where effects have been observed by those sounding the alarm. Astonishingly, this suggests that NPs might already be beyond threshold-effects in organisms and harming the marine biota.Here, we will deliver an innovative approach that will overcome the analytical limitations for detecting, mapping and quantifying NPs in realistic environmental settings. By combining 14C-labelling of NPs with the ultimate sensitivity of Accelerator Mass Spectrometry (AMS), METABOLISM will allow to investigate whether NPs in the oceans are already beyond "threshold-effect" concentrations in tissues. METABOLISM will: i) provide representative intrinsically radiolabelled NP models; ii) perform chronic NP exposures with a model organism (i.e. mussels) at environmentally realistic NP concentrations (ppt-levels); iii) develop the combustion AMS to generate toxicokinetic data; iv) explore the LA-AMS to produce spatially-resolve 14C measurement to quantify tissue distribution of NPs.The approach proposed here is essential and will produce unique, valuable and fundamental knowledge on the combined long-term accumulation of NPs in aquatic environments. This is critical for developing appropriate management strategies regarding plastic litter. If successful, METABOLISM will indeed support policy makers in improving environmental risk assessments of NPs and other contaminants of emerging concerns (CEC). It is envisioned that the approach proposed herein will enable a step-change in the research on CECs and will allow the study of many different aspects of their fates (e.g., transformation, fragmentation, biomineralization, biodistribution). METABOLISM chooses a highly innovative approach to address its research questions. It combines radiochemistry and unlock the power of the AMS to resolve important environmental questions. It will establish 14C-labelled NPs as a gold standard for performing realistic laboratory-based studies. It is fundamental research that will have a critical impact beyond its overall goal. The research proposed will, for instance, have a huge impact on the use of 14C as low-level tracer in biomedical studies (i.e. micro-dosing), where appropriate methods are often missing. The approach proposed is unique and will allow to perform ground-breaking science that goes beyond the state-of-the-art. METABOLISM builds an inter-disciplinary research team that integrates the relevant expertise in environmental analytical chemistry, radiochemistry and physics.