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

微塑料是小于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，雨水、废水和城市地区和农田的径流可以将微塑料带入河流、湖泊和溪流。然而，关于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中的这一差距。这些结果将决定土地利用对进入美国水生系统的微塑料的影响。这项研究的结果将被用来评估立法禁止消费产品中的微塑料的影响。这项研究将通过使用经过培训和参与的公民科学团体来测量其社区水中的塑料含量来促进。公民科学努力的影响将提高参与群体的科学素养，结果将传播给公众、利益攸关方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，但人们对来自不同陆地来源(例如，生物固体的陆地应用、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传输进行多管齐下的研究，包括实地调查和受控实地研究，以解决这一知识差距。具体目标是量化两条报告不足的陆上运输路线的微塑料的负载率、颗粒形态和成分，并评估跨越不同地理位置的淡水微塑料来源追踪技术。到目前为止，还没有研究评估跨地理位置的始终如一的来源跟踪。为了克服过去研究的这些局限性，将使用包括FT-IR和/或微型FT-IR在内的各种技术来进行聚合物识别。该项目团队将利用与公民科学家的持续合作来开展这项研究。陆地和水生微塑料的科学可防御性测量将通过广泛的质量控制计划实现，其中包括分析添加的样品和FT-IR评估样品。在该项目结束时，项目组将向科学、利益攸关方和公共社区传播有关不同地区微塑料装载的量化信息，以评估微塑料使用禁令和自愿淘汰的影响。这项研究是第一次直接评估生物固体和雨水在陆地上使用的塑料的通量。重要的是，这项工作将通过评估淡水系统中跨地理位置的来源追踪技术来促进科学发展，这是以前从未使用一致的方法进行的。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.