Atmospheric Microplastics Research Articles

Atmospheric deposition of microplastics in the megalopolis (Shanghai) during rainy season: Characteristics, influence factors, and source

Urban areas are the hardest hit by microplastic pollution, and deposition is an important part of microplastic migration and transport in the atmosphere, therefore, the study of microplastics in an urban atmospheric deposition is of great significance. This study aims to investigate the deposition characteristics of atmospheric microplastics in megapolis, to clarify the influence of meteorological and anthropogenic factors, and to analyze the sources of atmospheric microplastics. Six sampling sites in Shanghai were selected to collect atmospheric deposition samples during the rainy season. The mean deposition flux of microplastics was 3261.22 ± 2847.99 P·m−2·d−1 (median: 2559.70 P·m−2·d−1), and the types were mainly polyamide (PA, 27.79 %), polyethylene terephthalate (PET, 27.29 %), polypropylene (PP, 16.95 %), and polyvinyl fluoride (PVF, 12.88 %). The microplastic with the particle size of <1000 μm accounted for 88.23 %, and the shape was mainly fiber (73.55 %). The results of correlation analysis and variance analysis of microplastic characteristics with meteorological and anthropogenic factors (land-use, atmospheric pollutants, and urban indicators) showed that wind and precipitation had effects on deposition flux, size and shape, and were more significant at small scales (individual cities), while at large scales, the population was the main influence of microplastics. Atmospheric microplastics in Shanghai may be dominated by exogenous sources, through a combination of microplastic characteristics, wind and backward trajectories. This study further reveals the fate of urban atmospheric microplastics, which has implications for the study of global microplastic pollution.

Occurrence and characteristics of atmospheric microplastics in Mexico City

While atmospheric microplastics have attracted scientific attention as a significant source of microplastic contamination in the environment, studies in large population centers remain sparse. Here we present the first report on the occurrence and distribution of atmospheric microplastics in Mexico City (Latin America's second most densely populated city), collected using PM10 and PM2.5 active samplers at seven monitoring stations (urban, residential, and industrial) during the dry and wet seasons of 2020. The results showed that microplastics were detected in all of the samples examined, with mean microplastic concentrations (items m−3) of 0.205 ± 0.061 and 0.110 ± 0.055 in PM10 and PM2.5, respectively. The spatial distribution of microplastics showed seasonal variation, with greater abundances in locations closer to industrial and urban centers. There was also a significant difference in microplastic concentrations in PM10 and PM2.5 between the dry and wet seasons. The mean PM2.5/PM10 ratio was 0.576, implying that microplastics were partitioned more towards PM2.5 than PM10 in Mexico City. Fibers were the most prominent shape (>75 %), and blue was the most common color (>60 %). The size characteristics indicated microplastics of varying lengths, ranging from 39 to 5000 μm, with 66 % being <500 μm. Metal contaminants such as aluminum, iron, and titanium were detected using SEM-EDX on randomly selected microplastics. The microplastics were identified as cellophane, polyethylene, polyethylene terephthalate, polyamide, and cellulose (rayon) using ATR-FTIR spectral analysis. Our findings unravel the extent and characteristics of atmospheric microplastics in the Mexico City metropolitan area, which will aid future research to better understand their fate, transport, and potential health risks, demanding more investigations and close monitoring.

First comparison of sampler surface areas for atmospheric microfibre deposition.

Recent studies have reported on the widespread abundance of atmospheric microplastics (At-MPs) and atmospheric anthropogenic microfibres (At-AMFs) in urban and remote locations. This study sought to test whether there were differences in the quantity of deposited At-AMFs collected when comparing three different surface sampler areas (small: 0.0113 m2 (Φ = 120mm), medium: 0.0254 m2 (Φ = 180mm) and large: 0.0346 m2 (Φ = 210mm)). The analysis revealed no statistically significant variation in the number of At-AMFs recorded, when data was presented in At-AMFs per m2 day-1. However, our findings indicate that for any given individual sampling event, the amount of deposition can range by ∼ 150 to 200 At-AMFs m2 d-1 even if samplers are kept relatively close together. To account for this, we would recommend that future studies collect data in duplicate or triplicate. Our results suggest that data can be compared across different sites and geographical regions-at least if comparing the overall mean and standard deviation of all samples collected. These findings are important because currently there is no standard sampler size for passive collection of At-AMFs and At-MPs.

Are we ignoring the role of urban forests in intercepting atmospheric microplastics?

Occurrences and characteristics of atmospheric microplastics(MPs) have been widely studied by previous studies, while the mitigation of airborne MPs pollution was not well understood. In this study, atmospheric samples of MPs were collected in pairs on the rooftop and under trees composed of representative afforested species Ficus microcarpa in Chengdu, Southwest China, to explore whether trees could intercept MPs. Results showed that the daily life of human beings and textile industries of urban areas were sources of airborne MPs as revealed by chemical compositions and air trajectories. The trees with the high coverage degree (88%) and large three-dimensional spaces formed by leaves did have the ability to intercept high-density MPs with small sizes under the force of gravity. The intercepting rate was about 16.3%, 12,593 n/m2 of fibers and 347.69 kg of MPs could be intercepted by urban forests for one year. However, threshold values of rainfall intensity (12 mm/d) and rainfall amounts (14 mm) were found to limit the intercepting mechanism, and intercepting effects decrease with the increase of rainfall amounts (r =−0.71). This work provides quantitative evidence that elucidated urban forests may act as receptors of airborne MPs, thus improving the air quality and human health.

Long-range transport of atmospheric microplastics deposited onto glacier in southeast Tibetan Plateau

Micoroplastics (MPs) can be transported through atmospheric circulations, and have caused global attentions due to their potential risk to the environment. In this study, MPs in snowpit samples collected from Demula (DML) glacier in southeast Tibetan Plateau were investigated. The results showed that the average abundance of MPs in snow was 9.55 ± 0.9 items L−1, with dominant shapes of plastic fibers and films. MPs size was dominated by MPs <200 μm, with detected minimum size of 48 μm from the DML glacier. MPs in snowpit indicated seasonal variations, showing relatively higher abundance during the monsoon season than that during the non-monsoon season. The chemical composition of MPs and backward air mass trajectory modeling revealed that MPs in DML snowpit mostly originated from the atmospheric long-range transport, suggesting the glacier in southeast Tibetan Plateau can be a temporal sink of atmospheric MPs. The surface structure of the MPs was rough and adhered to a large amount of mineral dust and metallic particles, revealed that these MPs have undergone severe weathering during transportation and after deposition. Based on the MPs data, multi-year average precipitation, and glacier mass balance of DML glacier, the deposition flux of MPs on DML glacier was estimated to be about 7640 ± 720 to 9550 ± 900 items m−2 yr−1 and the export from melting water was about 5.9 ± 1.3 × 109 to 6.6 ± 1.4 × 109 items yr−1, indicating the glacier may be also an important source of MPs to the downstream ecosystems. These results provided the current status of MPs pollution on the Tibetan Plateau glaciers and new data to the study of MPs in typical cryospheric regions.

Occurrence of Atmospheric (Micro)plastics and the Characteristics of the Plastic Associated Biofilms in the Coastal Zone of Dalian in Summer and Autumn

Microplastics have been considered emerging pollutants that are widely distributed in the water, soil, and atmospheric environment. Compared with the research breadth and depth of microplastics in marine and terrestrial environments, the study of atmospheric microplastics is still in its infancy. At present, there are few studies on microplastics in the atmospheric environment, and the understanding of their pollution characteristics and potential risks remains insufficient. In this study, the occurrence characteristics of atmospheric (micro)plastics were investigated in the coastal zone of Dalian in summer and autumn. The bacterial community structures and functions of plastic-associated biofilms in the coastal zone of Dalian in summer and autumn were also studied. The results of this study showed that the dominant type of atmospheric microplastics in Dalian was fiber, and the main colors of atmospheric microplastics were transparent, blue, and black. The dominant particle size range of the atmospheric microplastics was less than 1 mm, and the polymer compositions were mainly polyethylene terephthalate, cellophane, and ethylene-propylene-diene terpolymer (>90%). Obvious weathering characteristics and biofilm formation could be observed on the surface of atmospheric microplastics. Proteobacteria, Cyanobacteria, and Actinobacteria were the dominant bacterial phyla that colonized on the surface of atmospheric plastic debris in the coastal zone of Dalian in summer and autumn. The results from the prediction of gene function showed that several functional genes that are closely related to human diseases exist in the epiphytic biofilms of atmospheric plastic debris. The results of this study can provide a scientific basis for the environmental and health risk assessment of atmospheric microplastics and their associated biofilms.

Inhalable microplastics prevails in air: Exploring the size detection limit.

Microplastics (MPs) are ubiquitous in the environment, including the atmosphere. Yet, the size detection limit in measuring airborne MPs undermines the determination of the human MP exposure level through inhalation and also restricts the understanding of airborne MPs pollution behavior. To comprehensively and accurately assess the MPs pollution features in air, we demonstrate a qualitative and quantitively method using Raman microscopy to characterize the suspended atmospheric MPs. Our methodology has achieved detailed characterization of MPs down to 1μm and ensured all the MPs to be counted regardless of their transparency. Further, a case study of indoor and outdoor samples from eight sampling sites were conducted in Shanghai, China. Inhalable MPs prevails in all samples with higher concentrations occur indoors. Indoor MPs varied strongly in composition compare to outdoor. Ventilation played an important role in lowering indoor MPs concentrations, and MPs in better ventilated indoors displayed similar distribution patterns as outdoors. MPs detected were mainly Polyethylene, Polyester, Phenolic Resin and Polyvinyl chloride. 77% of the Polyethylene detected were transparent films, suggesting the fragmentation from PE film products, such as plastic bags and cling films. Our work confirmed the widespread existences of inhalable MPs in air and provides solid foundations for future studies to understand the realistic MPs exposure conditions through inhalation.

Distribution and transport of atmospheric microplastics and the environmental impacts: A review

新兴污染物微塑料广泛分布于水体、陆地和大气环境中，大气中的微塑料研究起步较晚，但其潜在生态环境影响的范围更广。本文以2015年以来发表的大气微塑料相关文献为基础，对室外环境大气和室内大气中微塑料的分布、来源、迁移过程和生态环境影响进行了系统的综述。研究结果表明大气微塑料已分布于全球大气中，其分布特征与室内外环境、下垫面类型和污染扩散等环境因素相关。大气环境中微塑料主要来源于塑料制品的生产、使用和回收过程,少量来源于陆地和海洋中积累的微塑料；值得关注的是，新冠疫情中口罩的使用可能加重了大气中的微塑料污染。微塑料在大气环境中可发生悬浮、沉降和扩散等迁移过程，并受到微塑料形态、风力、风向和降水等因素的影响；微塑料在大气中的扩散，也称大气传输，是全球塑料循环的重要一环，目前多采用HYSPLIT进行后向轨迹模拟以研究其扩散路径，主要通过统计沉降量并结合空气动力学模型估算其传输量。大气中的微塑料能够影响区域大气环境质量，可能通过影响热收支和水循环等因素改变区域与全球气候；在迁移过程中吸附重金属、有机污染物和有害微生物，对暴露人群产生健康风险；通过进入食物链和提供微生态位等方式影响大气生态系统，通过沉降进入并影响陆地和水体生态系统。基于以上分析，本文提出未来大气微塑料的研究需要优先关注研究方法标准化、源清单建立、迁移机制和生态环境影响等问题。

Microplastic ingestion from atmospheric deposition during dining/drinking activities

Human-health risks from microplastics have attracted considerable attention, but little is known about human-exposure pathways and intensities. Recent studies posited that inhalation of atmospheric microplastics was the dominant human-exposure pathway. Herein, our study identified that atmospheric microplastics ingested from deposition during routine dining/drinking activities represent another important exposure pathway. We measured abundances of atmospheric-deposited microplastics of up to 105 items m-2 d-1 in dining/drinking venues, with 90% smaller than 100 µm and a dominance of amorphous fragments rather than fibers. Typical work-life scenarios projected an annual ingestion of 1.9 × 105 to 1.3 × 106 microplastics through atmospheric deposition on diet, with higher exposure rates for indoor versus outdoor dining/drinking settings. Ingestion of atmospheric-deposited microplastics through diet was similar in magnitude to presumed inhalation exposure, but 2–3 orders of magnitude greater than direct ingestion from food sources. Simple mitigation strategies (e.g., covering and rinsing dishware) can substantially reduce the exposure of atmospheric deposition microplastics through diet.

Airborne microplastics: A review of current perspectives and environmental implications

Microplastics (MPs), as an entirely anthropogenic type of pollution, are considered to be stratigraphic markers of the Anthropocene Epoch, and have become of increasing public concern over the past decade. Recent studies have revealed that the atmosphere is an efficient medium to disseminate MPs from their sources to remote mountains and marine areas. However, current research on atmospheric MPs (i.e. airborne MPs) is generally less highlighted than MP water and soil pollution studies due to the lack of standard methods for the identification and quantification of atmospheric MPs. This paper reviews the published literature on airborne MPs, gives an overview of the advantages and disadvantages of current airborne MPs collection techniques, extraction methods and identification (i.e., ‘passive’ and ‘active’ sampling, density separation and visual identification), and lays a foundation for future studies. The physical and chemical characteristics, classification, spatial and temporal scale distributions, sources, transport, and environmental impacts of airborne MPs are summarized. There are substantial research gaps in the quantification of airborne MPs and the exploration of toxicity mechanisms of inhalable MPs. The establishment of accredited methods is an urgent challenge for a better understanding on airborne MPs and their environmental and health effects. As one of the constituents in many aerosols, airborne MPs should be treated as a recognized pollutant for long-term monitoring, and the factors that specifically affect airborne MPs could be better addressed by means of the characterization of individual MPs. In the future, the effects and interaction of MPs in the atmosphere, lithosphere and hydrosphere are also of critical importance.

Atmospheric microplastics in the Northwestern Pacific Ocean: Distribution, source, and deposition

Microplastic pollution is recognized as a ubiquitous global issue. However, limited information is available concerning microplastics in the marine air. Here we present the occurrence and distribution of atmospheric microplastics in the Northwestern Pacific Ocean, with abundance ranging from 0.0046 to 0.064 items/m3. The microplastics were in various shapes and polymer types, of which fibrous rayon (67%) and polyethylene terephthalate (PET, 23%) accounted for the majority. The atmospheric microplastics in the pelagic area showed higher abundance and smaller size compared to those in the nearshore area, indicating smaller-sized microplastics in the atmosphere might travel long distances over the ocean. The atmospheric microplastic distribution was not only affected by weather conditions but might also be related to the microplastic sources. The microplastic polymer types combined with the backward trajectory model analysis showed that atmospheric microplastics in the Northwestern Pacific Ocean mainly originated from the land and the adjacent oceanic atmosphere. Spearman's correlation coefficient of the relationship between the features of microplastics in the atmosphere and surface seawater tended to increase with increasing offshore distances. Our field-based research revealed that atmospheric microplastics were a non-negligible source of marine microplastic pollution.

Sources and fate of atmospheric microplastics revealed from inverse and dispersion modelling: From global emissions to deposition

We combine observations from Western USA and inverse modelling to constrain global atmospheric emissions of microplastics (MPs) and microfibers (MFs). The latter are used further to model their global atmospheric dynamics. Global annual MP emissions were calculated as 9.6 ± 3.6 Tg and MF emissions as 6.5 ± 2.9 Tg. Global average monthly MP concentrations were 47 ng m-3 and 33 ng m-3 for MFs, at maximum. The largest deposition of agricultural MPs occurred close to the world’s largest agricultural regions. Road MPs mostly deposited in the East Coast of USA, Central Europe, and Southeastern Asia; MPs resuspended with mineral dust near Sahara and Middle East. Only 1.8% of the emitted mass of oceanic MPs was transferred to land, and 1.4% of land MPs to ocean; the rest were deposited in the same environment. Previous studies reported that 0.74–1.9 Tg y-1 of land-based atmospheric MPs/MFs (< 5 mm) are transported to the ocean, while riverine transport is between 3.3 and 14 Tg y-1. We calculate that 0.418 ± 0.201 Tg y-1 MPs/MFs (size up to 250 and 2500 µm) were transported from the land to ocean (large particles were ignored). Model validation against observations showed that particle removal must be urgently updated in global models.

Occurrence and human exposure risks of atmospheric microplastics: A review

Microplastics have attracted global attention as an emerging and ubiquitous contaminant in the environment. There are several pathways of human microplastic exposure, however, atmospheric microplastic pollution has yet rarely been elucidated systematically, especially the impact of atmospheric microplastics on human health. This review summarizes the current state of knowledge about microplastic pollution in atmosphere based on sample types, and the factors affecting microplastic transport or deposition as well as human exposure and potential risks on humans are discussed. Microplastics have been reported in suspended particular particles, atmospheric fallout, road dust and wet precipitation around the world, but the abundance of atmospheric microplastics varies in different regions. The abundance of microplastics in the atmosphere is greatly affected by human activities and meteorological factors, but the influence mechanisms on the transport and deposition processes remain to be clarified. Furthermore, atmospheric microplastics can pose potential health threats once inhaled, and the intake is age-related, with probably less intake for adults than children. Knowledge gaps and perspectives for further studies of atmospheric microplastic pollution status and human risk assessments are also proposed.

Airborne and marine microplastics from an oceanographic survey at the Baltic Sea: An emerging role of air-sea interaction?

Microplastics (MPs) pollution is one of the most important problems of the Earth. They have been found in all the natural environments, including oceans and the atmosphere. In this study, the concentrations of both atmospheric and marine MPs were measured over the Baltic along a research cruise that started in the Gdansk harbour, till the Gotland island, and the way back. A deposition box (based on a combination of active/passive sampling) was used to collect airborne MPs while, marine MPs concentrations were investigated during the cruise using a dedicated net. Ancillary data were obtained using a combination of particle counters (OPC, LAS and CPC), Aethalometer (AE33 Magee Scientific), spectrofluorometer (sea surface samples, Varian Cary Eclipse), and meteorological sensors. Results showed airborne microplastics average concentrations higher in the Gdansk harbour (161 ± 75 m−3) compared to the open Baltic Sea and to the Gotland island (24 ± 9 and 45 ± 20 m−3). These latter values are closer to the ones measured in the sea (79 ± 18 m−3). The MPs composition was investigated using μ-Raman (for the airborne ones) and FTIR (for marine ones); similar results (e.g. polyethylene, polyethylene terephthalates, polyurethane) were found in the two environmental compartments. The concentrations and similar composition in air and sea suggested a linkage between the two compartments. For this purpose, the atmospheric MPs' equivalent aerodynamic diameter was calculated (28 ± 3 μm) first showing the capability of atmospheric MPs to remain suspended in the air. At the same time, the computed turnover times (0.3–90 h; depending on MPs size) limited the transport distance range. The estimated MPs sea emission fluxes (4–18 ∗ 106 μm3 m−2 s−1 range) finally showed the contemporary presence of atmospheric transport together with a continuous emission from the sea surface enabling a grasshopper long-range transport of microplastics across the sea.

Outdoor Atmospheric Microplastics within the Humber Region (United Kingdom): Quantification and Chemical Characterisation of Deposited Particles Present

Atmospheric microplastics (MPs) have been consistently captured within air samples on a global scale. Locations with high human activity are reported to have high MP levels. An urban sampling site in the Humber region (U.K.) has been sampled over a 13-month period, providing a seasonal variation profile of MP levels, size, shape, and polymer types that humans are exposed to. Mean MP levels, measured using passive fallout into a container, were 3055 ± 5072 MP m−2 day−1 (1164 median). An increase in levels with a decrease in MP size was observed, consisting of mainly film-shaped MPs (67%) that were polyethylene (31%) and nylon (28%) polymer types. No relationship between rainfall and MP fallout levels was observed. In parallel, MPs within five urbanised locations relevant to human exposure were characterised over a 2-week period. An overall MP mean (and standard deviation) of 1500 ± 1279 was observed (1012 median), from which petroleum resin accounted for 32% of MP polymer type, with a higher prevalence within industrial and roadside zones. These comprised mainly fragment (52%) and film (42%) shapes, and the MPs levels increased with decreasing particle size. The results provide novel information on characterising polymer levels and types, and can inform cellular toxicity studies, investigating the consequences of human MP exposure.

Microplastics in the atmosphere: a review

Microplastics (MPs) are ubiquitous environmental contaminants of considerable persistence and have been a global concern for the past decade. Recently, atmospheric MPs have gained attention. The presence of MPs in the air has been reported from different regions and in air masses over water bodies, demonstrating MPs’ capability of long-range transport and wide spatial distribution away from their source of origin. This review of atmospheric MPs raises questions about the validity and legitimacy of approaches adopted for assessing MP in indoor and outdoor aerosols. The review also provides insight into active and passive sampling techniques and draws attention to the use of the data produced. MP abundance in the atmosphere varies widely among studies due to the disparities in methods employed and the heterogeneity in reporting, making comparisons across spatio-temporal domains infructuous. This review also highlights the paucity of data on atmospheric MPs, and the eminent need to harmonize the methodology for generating a useful comparable dataset that can be used for human health risk assessments.

First Quantification and Chemical Characterization of Atmospheric Microplastics Observed in Seoul, South Korea

First Quantification and Chemical Characterization of Atmospheric Microplastics Observed in Seoul, South Korea

Ecological and human health risks of atmospheric microplastics (MPs): a review

Microplastics (MPs) in the atmosphere are ubiquitous and persistent emerging pollutants which have been an environmental issue of global concern.

Long Range Transport of Atmospheric Microplastics Deposited Onto Glacier in Southeast Tibetan Plateau

Long Range Transport of Atmospheric Microplastics Deposited Onto Glacier in Southeast Tibetan Plateau

The deposition of atmospheric microplastics in Jakarta-Indonesia: The coastal urban area

The air pollution in Jakarta has been recorded regularly; meanwhile, the information of atmospheric microplastics is still unknown. This study examines the characteristics (shape, size, and polymer) and deposition rate of atmospheric microplastics in Jakarta. The sample was obtained by putting a rain gauge for 12 months. All microplastic samples were analyzed for polymer using FT-IR. The lowest to the highest percentage of atmospheric microplastic based on shape were foam<fragment<fiber, meanwhile based on size were of 500–1000 μm < 300–500 μm. The detected polymers included polyester, polystyrene, polybutadiene, and polyethylene. The microplastics deposition rate ranged from 3 to 40 particles m−2d−1, with an average of 15 particles m−2d−1. The rainy season's deposition rate (23.422 particles m−2d−1) was higher than the dry season (5.745 particles m−2d−1). Our study proves that the atmospheric microplastic exists in Jakarta's air and needs to be considered to monitor by the government regularly.