Collaborative Research: Terrestrial microplastic pollution: understudied sources, source tracking, and citizen science

微塑料是指小于5毫米的塑料颗粒。微塑料在全球的水生和陆地环境中都有发现。过去的研究已经证实，来自城市和农田的雨水、废水和径流可以将微塑料带入河流、湖泊和溪流。然而，微塑料如何在环境中移动的细节在很大程度上是未知的。这项研究的目标是通过测量城市、郊区和农村地区的塑料来解决我们知识上的这一差距。这些结果将确定土地利用对进入美国水生系统的微塑料的影响。这项研究的结果将用于评估立法禁止在消费品中使用微塑料的影响。接受过培训并参与测量社区水中塑料含量的公民科学团体将为这项研究提供便利。公民科学努力的影响将提高参与团体的科学素养，结果将传播给公众、利益相关者和负责管理微塑料废物的监管机构。尽管研究表明，每年有超过1270万公吨的微塑料废物进入海洋，但人们对不同陆地来源（例如生物固体的土地应用、城市雨水）的微塑料的相对重要性知之甚少。将对微塑料在环境中的迁移进行多管齐下的研究，包括实地调查和受控的实地研究，以解决这一知识差距。具体目标是量化两条未被报道的陆地运输路线的微塑料装载率、颗粒形态和组成，并评估不同地理位置淡水中的微塑料来源跟踪技术。到目前为止，还没有研究评估过跨地域的来源追踪。为了克服过去研究的这些局限性，聚合物鉴定将使用各种技术进行，包括FT-IR和/或微FT-IR。项目团队将利用与公民科学家正在进行的合作来开展这项研究。通过广泛的质量控制项目，包括对加标样品和FT-IR评估样品的分析，将对陆地和水生微塑料进行科学可靠的测量。在本项目结束时，项目团队将向科学界、利益相关者和公共社区传播有关不同地区微塑料负荷的定量信息，以便评估微塑料使用禁令和自愿逐步淘汰的影响。这项研究是第一个直接评估生物固体和雨水对塑料通量的影响的研究。重要的是，这项工作将通过评估淡水系统中跨地理位置的源跟踪技术来推进科学，这在以前没有使用一致的方法进行过。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Microplastics are plastic particles smaller than 5 millimeters. Microplastics are found in aquatic and terrestrial environments across the globe. Past research has established that stormwater, wastewater effluent, and runoff from urban areas and agricultural fields can carry microplastics into rivers, lakes, and streams. However, the details of how microplastics move in the environment is largely unknown. The goal of this research is to address this gap in our knowledge by measuring plastics in urban, suburban, and rural areas. These results will determine the influence of land use on microplastics entering into aquatic systems in the US. Results from this study will be used to assess the impact of legislative bans on microplastics in consumer products. The research will be facilitated by using citizen science groups trained and engaged to measure plastic levels in water in their communities. The impact of the citizen science efforts will increase the scientific literacy of the engaged groups, and results will be disseminated to the public, stakeholders, and regulatory agencies tasked with managing microplastics wastes. Although research has shown that over 12.7 million metric tons of microplastic waste enters the ocean on an annual basis, the relative importance of microplastics from different terrestrial sources (e.g., land application of biosolids, urban stormwater) is poorly understood. A multipronged study of microplastic transport in the environment involving field surveys and controlled field studies will be performed to address this knowledge gap. The specific objectives are to quantify loading rates, particle morphology, and composition of microplastics for two under-reported terrestrial transport routes and evaluate microplastic source tracking techniques in freshwater across disparate geographies. To date, no study has evaluated source tracking consistently across geographies. To overcome these limitations of past research, polymer identification will be performed using various techniques including FT-IR and/or micro-FT-IR. The project team will leverage ongoing collaborations with citizen scientists to carry out the research. Scientifically defensible measurements of terrestrial and aquatic microplastics will be achieved through an extensive quality control program that includes the analysis of spiked and FT-IR evaluated samples. At the conclusion of this project, the project team will disseminate quantitative information to the scientific, stakeholder, and public communities on microplastics loading across diverse geographies that will allow assessment of the influence of microplastic usage bans and voluntary phase outs. This study represents one of the first to directly evaluate the flux of plastics from land application of biosolids and stormwater. Importantly, this work will advance science by evaluating source tracking techniques across geographies in freshwater systems, which has not been performed previously using consistent methods.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.