Collaborative Research: CAS-MNP--Precursors of Long-Distance Aerial Transport of Microplastics from Urban Environments

微塑料（MPs）是一种尺寸小于5毫米的塑料颗粒，已经在水环境中进行了超过15年的研究。这些研究提高了公众对MPs对水生生态系统（特别是鱼类及其食物网）的不利影响的认识，因此许多国家开始限制塑料的使用和处置。海洋被视为多磺酸盐的最终汇，多磺酸盐被认为主要通过水生环境（流入小溪、河流、溪流或污水排放等）在海洋中运输。越来越多的证据表明，MPs存在于许多被认为是原始的陆地系统中。然而，只有对远距离大气输送（100公里）和沉积的推测才能解释它们在这些地区的存在。这些发现激发了人们对下院议员如何从主要来源逃离并通过空中长途旅行的机制的兴趣。由于人类活动产生的物质会导致MPs的形成，因此城市被认为是MPs的主要来源。该项目的重点是了解MPs从城市源输送到大气中的主要过程和机制。该项目将为政策制定者和生态毒理学家提供必要的发现，他们关注的是，鉴于使用塑料的行业的迅速扩张，是否以及如何监管下院议员。需要面对的艰巨的科学挑战是城市环境中空气流动的复杂性和不同类型的颗粒物释放，城市冠层（街道、建筑物等）与颗粒物沉积/逸出之间的相互作用，颗粒物特性和天气条件。为了实现整个项目目标，提出了3个相互关联的科学问题：Q1与城市排放源相关的MPs如何被运输出城市系统？(任务1 - 3);城市地表形态的不同特征（如高密度城市中心与低密度居民区）如何与污染物源/汇分布（街道网络）的空间配置相互作用，从而影响污染物的运输和沉积？（任务4）和Q3如何量化与城市地表形态和天气模式相关的MPs成为空气传播的机会？(5)任务。最先进的计算机模拟运行和MP轨迹跟踪模型将被接口并用于解决Q1-Q3问题。将系统地探索表征城市的城市形态特性和MPs的物理化学特性，以揭示形态、MPs特性、天气模式和MPs出城运输之间的联系。数据驱动的方法（如机器学习）也将应用于模拟结果，以便制定可用于未来MP法规的模型。该项目探索了一种新的推广活动，利用非营利组织“维基教育”的资源。维基教育专门培训学生编辑维基百科中的信息，同时提供关于当今社会和可预见的未来所面临的问题的高质量信息。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。

Micro-plastics (MPs), which are plastic particles of sizes smaller than 5 mm, have been studied in aqueous environments for more than 15 years. These studies have raised public awareness about the adverse effects of MPs on aquatic ecosystems (fish in particular and their food-web in general) and many countries are beginning to limit the use and disposal of plastics because of them. Oceans are viewed as the ultimate sink of MPs, where MPs are assumed to be transported primarily via aquatic environments (runoff to creeks, rivers, streams, or sewage discharge, etc.). There is mounting evidence that MPs are present in many terrestrial systems that are presumed to be pristine. However, only speculation about long-distance atmospheric transport ( 100 km) and deposition has been offered to explain their presence in these regions. Such findings are prompting interest in the mechanisms by which MPs escape from their main source and travel long-distance aerially. Because of human activities that produce materials that lead to the formation of MPs, cities are considered major sources of MPs. This project is centered on understanding the primary processes and mechanisms in which MPs are transported from urban sources to the atmosphere. The project will lead to findings necessary for policy makers and eco-toxicologists concerned with whether and how MPs should be regulated in light of the rapid expansion in industries that use plastics. Daunting scientific challenges to be confronted are the complexity of air flow and variable releases of MP types in urban settings, the interaction between urban canopy (streets, buildings, etc.) and deposition/escape of MPs, the MP particulate properties, and weather conditions. To address the overall project goal, 3 inter-related science questions are proposed: Q1 How MPs associated with urban emission sources get transported out of an urban system? (Tasks 1-3); Q2 How do different characteristics of urban surface morphology (e.g. high-density urban center versus low-density residential areas) interact with the spatial configurations of MP source/sink distributions (street network) to impact their transport and deposition? (Task 4), and Q3 How to quantify the chance of MPs becoming air-borne in relation to urban surface morphology and weather patterns? (Task 5). The state-of-the science computer simulation runs and MP trajectory tracking models will be interfaced and used to address Q1-Q3. The urban morphological properties characterizing cities and the physical-chemical properties of MPs will be systematically explored to unpack connections between morphology, MP property, weather patterns and the transport of MPs out of cities. Data-driven approaches such as machine-learning will also be applied to simulation results to enable formulation of models that can be used for MP regulations in the future. The project explores a new outreach activity that leverages resources of a non-profit organization `Wiki Education'. Wiki Education specializes in training students to edit information in Wikipedia while providing high-quality information on issues confronting society today and in the foreseeable future.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.