Understanding UK airborne microplastic pollution: sources, pathways and fate

微小的塑料碎片，被称为微塑料，是一类复杂的颗粒污染物。它们源于降解的塑料垃圾和人类活动，例如洗合成衣服或使用合成轮胎驾驶，在世界各地的栖息地无处不在。微塑料包括不同的塑料类型和形状，大小跨越几个数量级，并藏有有害的化学物质和微生物。实验室研究表明，它们会对水生和陆生物种造成生物危害，因此欧盟委员会建议采取措施，尽量减少它们的释放。最近有证据表明，室外灰尘中存在微塑料，这表明微塑料可以通过空气传播，使空气成为扩散和进入更广泛环境的新媒介。这也引起了人们对人类通过吸入接触微塑料的担忧。它们是否以足够小的尺寸进入中央和深气道尚未被测量，但对于未来研究微塑料对人口健康的影响至关重要。考虑到它们的潜在来源，预计城市环境中的水平会更高，既会增加人口暴露，又会成为原始和敏感生境的来源。该项目旨在评估英国空气中微塑料污染的程度和命运。这将包括检查微塑料的来源、大小分布、运输和命运，这将通过以下目标实现：为不同类型空气样本中的微塑料制定标准化工作流程和分析方法（O1）；微塑料在不同环境下的大气沉积负荷测量（O2）；了解微塑性沉积（O3）的季节变化；城市和农村环境中空气中微塑料尺寸分布的量化（O4）；识别空气中微塑料（O5）的来源（点、线、区）；表明微塑料是否垂直混合在150m (O6)；以及在多媒体研究中对微塑料的环境命运的评估（O7）。微塑料污染作为一个领域正在呈指数级增长，但对大气的研究仍然不足。这是英国第一个解决空气中微塑料问题的大型项目，也是第一个测量与健康有关的微塑料尺寸分数的大型项目，解决了两个关键的知识空白。关于空气中微塑料的各种来源和水平的证据将提供一个基线，以评估减少微塑料释放的有效性，并表明是否有必要将其纳入未来的空气质量监测计划和沉积网络。颗粒物对健康的相关影响已得到确认，主要与道路运输和燃料燃烧排放有关。随着全球减少此类排放的压力增加，PM的组成可能会发生变化。结合塑料使用量的预测增长，特别是在纺织行业（每年4%），空气中微塑料的比例浓度将变得越来越重要。因此，建立空气中微塑料负担的基线知识是及时的。

Microscopic plastic debris, known as microplastics, are a complex class of particulate pollutants. They originate from degraded plastic litter and human activity, such as washing synthetic clothes or driving with synthetic tyres, and are ubiquitous across habitats worldwide. Microplastics comprise different plastic types and shapes, span several orders of magnitude in size, and harbour harmful chemicals and microbes. They have shown to cause biological harm in aquatic and terrestrial species in laboratory studies, leading the European Commission to recommend measures to minimise their release. Recent evidence demonstrating their presence in outdoor dust suggests that microplastics can be airborne, presenting air as a novel vehicle for dispersion and entry into the wider environment. This also raises concern for human exposure to microplastics via inhalation. Whether they occur in sizes small enough to enter the central and deep airways has not been measured but is imperative for future studies on the impacts of microplastics on population health. Considering their potential sources, higher levels are anticipated in urban environments, presenting both a greater population exposure and a source to pristine and sensitive habitats.This project aims to assess the extent and fate of airborne microplastic pollution in the UK. This will include examining microplastic sources, size-distribution, transport, and fate, which will be achieved through the following objectives: development of a standardised work flow and analytical methods for microplastics in different types of air samples (O1); measurement of atmospheric deposition loadings for microplastics in different environments (O2); understanding the seasonal variation of microplastic deposition (O3); quantification of size distributions for airborne microplastics in urban and rural environments (O4); identification of the sources (point, linear, area) of airborne microplastics (O5); an indication of whether microplastics are vertically mixed >150 m (O6); and an evaluation of the environmental fate of microplastics in a multi-media study (O7).Microplastic pollution is growing exponentially as a field, yet the atmosphere remains understudied. This is the first large UK project to address airborne microplastics and the first to measure microplastics in health-relevant size fractions, addressing two key knowledge gaps. Evidence of the various sources and levels of airborne microplastics will provide a baseline to assess the efficacy of efforts to minimise release and indicate whether it is necessary to incorporate into future air quality monitoring programmes and deposition networks. The associated health effects of particulate matter (PM) are well-established and primarily associated with road transport and fuel burning emissions. As global pressure to reduce such emissions increases, PM composition is likely to shift. In combination with a predicted increase in plastic use, especially in the textile sector (4%/year), the proportional concentration of airborne microplastics will become increasingly important. It is therefore timely to establish baseline knowledge of airborne microplastic burdens.