Understanding UK airborne microplastic pollution: sources, pathways and fate

微小的塑料碎片，又称微塑料，是一种复杂的颗粒性污染物。它们源于降解的塑料垃圾和人类活动，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，跨越几个数量级的大小，并含有有害化学物质和微生物。实验室研究表明，它们会对水生和陆地物种造成生物危害，导致欧盟委员会建议采取措施，将它们的释放降至最低。最近的证据表明，在室外粉尘中存在微塑料，这表明微塑料可以在空气中传播，使空气成为一种分散和进入更广泛环境的新工具。这也引起了人们对人类通过吸入接触微塑料的担忧。它们的尺寸是否小到足以进入中央和深层呼吸道还没有被测量，但对于未来关于微塑料对人口健康的影响的研究来说，这是必不可少的。考虑到它们的潜在来源，预计城市环境中的微塑料污染水平会更高，这既意味着更大的人口暴露，也是原始和敏感栖息地的来源。该项目旨在评估英国空气中微塑料污染的程度和命运。这将包括审查微塑料的来源、粒度分布、运输和去向，将通过下列目标来实现：制定不同类型空气样品中微塑料的标准化工作流程和分析方法(O1)；测量不同环境中微塑料的大气沉积负荷(O2)；了解微塑料沉积的季节变化(O3)；量化城市和农村环境中空气微塑料的粒度分布(O4)；确定空气微塑料的来源(点、线、面)；指示微塑料是否垂直混合；150米(O6)；在一项多媒体研究中对微塑料的环境命运进行了评估(O7)。作为一个领域，微塑料污染呈指数级增长，但对大气的研究仍然不足。这是英国第一个处理空气中微塑料的大型项目，也是第一个测量与健康相关的尺寸组分的微塑料的项目，解决了两个关键的知识空白。空气中微塑料的各种来源和水平的证据将为评估尽量减少排放的努力的效力提供基线，并表明是否有必要将其纳入未来的空气质量监测方案和沉积网络。颗粒物(PM)对健康的相关影响是公认的，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的构成可能会发生变化。再加上预计塑料使用量的增加，特别是在纺织行业(4%/年)，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荷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.