Microplastics in the atmosphere of Ahvaz City, Iran

Profusion of microplastics in dental healthcare units; morphological, polymer, and seasonal trends with hazardous consequences for humans

Given the convenience of using plastics, addressing the growing concerns about their hazardous health effects is imperative. Consequently, a comprehensive risk assessment is necessary to gauge the potential harm microplastics pose. With its urgent call to action, this study aimed to investigate the indoor source and abundance of microplastics in private dental units during routine professional activities. The current analyzed microplastic quantity variations based on morphological characteristics, seasonal fluctuations and polymer-types. The polymer hazard index (PHI) was calculated to evaluate the significant human health risks posed to dental professionals by inhalation of microplastics. Dust samples were collected using a clean brush and steel pan from various flat and horizontal surfaces within each dental unit. The study found that clinical dental units had fewer microplastics (587 ± 184.9 MPs/g/day) than teaching hospitals (1083.80 ± 133.7MPs/g/day), with comparatively more abundance in winter (31 %). ATR-FTIR analysis determined polyethylene terephthalate to be a more abundant polymer (39 %). This study also found an average inhalation microplastic intake risk of 20.23 MP/g/day and 5259.85 MP/g/year for clinical and 29.45 MP/g/day and 765.12 MP/g/year for teaching hospital dental units. Female dental professionals have 1.1 times more microplastic inhalation risks than male dental professionals. According to PHI findings, overall minor to medium polymer risk was determined. In conclusion, this evidence-based research underscores the urgent need for a shift towards more sustainable practices in the dental healthcare sector. Dental professionals should prioritize using non-plastic material protective equipment and a proper ventilation system to reduce exposure to these particles.

Planetary boundaries transgressions: A review on the implications to public health

This literature review systematically examines the impacts of violating planetary boundaries from 2009 to 2023, emphasizing the implications for human health. Planetary boundaries define safe operational limits for Earth's systems, and their transgression poses significant threats to environmental stability and public health. This paper reviews extensive research on the health effects of breaches in these boundaries, including climate change, biodiversity loss, freshwater use, and aerosol loading. The review integrates findings from numerous studies, providing a critical overview of health impacts across various global regions. The analysis underscores the intricate links between planetary boundaries breaching impacts, highlighting urgent policy and governance challenges. The study's outcomes aim to inform policymakers, businesses, and communities, promoting sustainable development and resilience in the face of escalating global challenges.

A review on advancements in atmospheric microplastics research: The pivotal role of machine learning

Microplastics (MPs), recognized as emerging pollutants, pose significant potential impacts on the environment and human health. The investigation into atmospheric MPs is nascent due to the absence of effective characterization methods, leaving their concentration, distribution, sources, and impacts on human health largely undefined with evidence still emerging. This review compiles the latest literature on the sources, distribution, environmental behaviors, and toxicological effects of atmospheric MPs. It delves into the methodologies for source identification, distribution patterns, and the contemporary approaches to assess the toxicological effects of atmospheric MPs. Significantly, this review emphasizes the role of Machine Learning (ML) and Artificial Intelligence (AI) technologies as novel and promising tools in enhancing the precision and depth of research into atmospheric MPs, including but not limited to the spatiotemporal dynamics, source apportionment, and potential health impacts of atmospheric MPs. The integration of these advanced technologies facilitates a more nuanced understanding of MPs' behavior and effects, marking a pivotal advancement in the field. This review aims to deliver an in-depth view of atmospheric MPs, enhancing knowledge and awareness of their environmental and human health impacts. It calls upon scholars to focus on the research of atmospheric MPs based on new technologies of ML and AI, improving the database as well as offering fresh perspectives on this critical issue.

Microplastic atmospheric pollution in an urban Southern Brazil region: What can spider webs tell us?

The World Health Organization categorizes air pollution as the presence of one or more contaminants in the atmosphere such as smoke, dust, and particulate matter like microplastics, which are considered a priority pollutant. However, only a few studies have been developed on atmospheric pollution, and knowledge about MPs in the atmosphere is still limited. Spider webs have been tested and used as a passive sampling approach to study anthropogenic pollution. Despite this, studies on microplastic contamination using spiderwebs as samplers are scarce. Thus, this study uses spider webs as passive indicators to investigate air quality regarding microplastic contamination in an urbanized area. Therefore, 30 sampling points were selected, and webs of Nephilingis cruentata were collected. The spider webs were dipped in KOH 10 %. After digestion, the solution was washed and sieved through a 90 µm geological sieve. The remaining material was transferred to a Petri dish with filter paper, quantified, and identified by type and color. The chemical composition of the polymers was determined using Raman spectroscopy. 3138 microplastics were identified (2973 filaments and 165 fragments). The most frequent colors were blue and black. Raman spectroscopy revealed five types of polymers: Isotactic Polypropylene, Polyethylene Terephthalate, Polyurethane, Polyamide, and Direct Polyethylene.

A green approach to nanoplastic detection: SERS with untreated filter paper for polystyrene nanoplastics

Plastic pollution at the nanoscale continues to pose adverse effects on environmental sustainability and human health. However, the detection of nanoplastics (NPLs) remains challenging due to limitations in methodology and instrumentation. Herein, a "green approach" for surface-enhanced Raman spectroscopy (SERS) was exploited to detect polystyrene nanospheres (PSNSs) in water, employing untreated filter paper and a simple syringe-filtration set-up. This SERS protocol not only enabled the filtration of nano-sized PSNSs, which are smaller than the pore size of the ordinary filter paper, but also offered SERS enhancement by utilizing quasi-spherical-shaped silver nanoparticles (AgNPs) as the SERS-active substrate. The filtering of NPLs was accomplished by adding an aggregating agent to the nanoparticle mixture, which caused the aggregation of NPLs and AgNPs, resulting in a larger cluster and more hot spots for SERS detection. The optimal aggregating agent and its concentration, as well as the volume ratio between the AgNPs and NPLs, were also optimized. This SERS method successfully detected and quantified PSNSs of various sizes (i.e., 100, 300, 460, 600, and 800 nm) down to a limit of detection (LOD) of about 0.31 μg mL-1. The method was also validated against the presence of several interferents (i.e., salts, sugars, amino acids, and surfactants) and was proven practical, as evidenced by the detection of 800nm PSNSs in drinking and tap water (LODs of 1.47 and 1.55 μg mL-1, respectively).

Airborne transboundary microplastics-A Swirl around the globe

Microplastics are persistent pollutants discovered and extensively researched in marine, freshwater, and terrestrial ecosystems but have yet to receive attention in an atmospheric context. Although recent reports stated the presence of microplastics in the air, their global existence and distribution are not critically discussed to date. This review aimed to investigate the current status of research on atmospheric microplastics through bibliometric analysis and by comparing and summarising published research on global distribution. The review also provides a summary of methods that have been used to collect samples, identify microplastics, quantify their occurrence, and determine their transport mechanisms. The bibliometric analysis revealed that atmospheric microplastic studies predominantly originated in China. Clothing, vehicle, and tire materials were the major primary sources while house furniture, construction materials, landfills, urban dust, plastic recycling processes, and agricultural sludge were precursor secondary sources. Polyethylene, polypropylene, and polyethylene terephthalate microfibres have most frequently found in indoor and outdoor atmospheres. Level of urbanization and temporal or spatial distributions governs the fate of airborne microplastics, however, the knowledge gap in the retention and circulation of microplastics through the atmosphere is still large. Many challenges and limitations were identified in the methods used, presentation of data, aerodynamic processes facilitating atmospheric transport, and scarcity of research in spatially and temporally diverse contexts. The review concluded that there was a greater need for globalization of research, methods and data standardization, and emphasizes the potential for future research with atmospheric transportation modelling and thermochemical analysis.

Probabilistic Estimation of Airborne Micro- and Nanoplastic Intake in Humans

Little research exists on the magnitude, variability, and uncertainty of human exposure to airborne micro- and nanoplastics (AMNPs), despite their critical role in human exposure to MNPs. We probabilistically estimate the global intake of AMNPs through three main pathways: indoor inhalation, outdoor inhalation, and ingestion during indoor meals, for both children and adults. The median inhalation of AMPs is 1,207.7 (90% CI, 42.5-8.48 × 104) and 1,354.7 (90% CI, 47.4-9.55 × 104) N/capita/day for children and adults, respectively. The annual intake of AMPs is 13.18 mg/capita/a for children and 19.10 mg/capita/a for adults, which is approximately one-fifth and one-third of the mass of a standard stamp, assuming a consistent daily intake of medians. The majority of AMP number intake occurs through inhalation, while the ingestion of deposited AMPs during meals contributes the most in terms of mass. Furthermore, the median ANP intake through outdoor inhalation is 9,638.1 N/day (8.23 × 10-6 μg/d) and 5,410.6 N/day (4.62 × 10-6 μg/d) for children and adults, respectively, compared to 5.30 × 105 N/day (5.79 × 10-4 μg/d) and 6.00 × 105 N/day (6.55 × 10-4 μg/d) via indoor inhalation. Considering the increased toxicity of smaller MNPs, the significant number of ANPs inhaled warrants great attention. Collaborative efforts are imperative to further elucidate and combat the current MPN risks.

Characteristics, distribution patterns and sources of atmospheric microplastics in the Bohai and Yellow Seas, China

Although the prevalence of microplastics in the atmosphere has recently received considerable attention, there is little information available regarding the distribution of atmospheric microplastics over oceanic regions. In this study, during the summer and autumn months of 2022, we investigated atmospheric microplastics in four marine regions off the eastern coast of mainland China, namely, the southern, middle, and northern regions of the Yellow Sea, and the Bohai Sea. The abundance of atmospheric microplastics in these regions ranged from 1.65 to 16.80 items/100 m3 during summer and from 0.38 to 14.58 items/100 m3 during autumn, although we detected no significant differences in abundance among these regions. Polyamide, chlorinated polyethylene, and polyethylene terephthalate were identified as the main types of plastic polymer. On the basis of meteorological data and backward trajectory model analyses, we established that the atmospheric microplastics detected during summer were mainly derived from the adjacent marine atmosphere and that over the continental landmass in the vicinity of the sampling area, whereas microplastics detected during autumn appear to have originated mainly from the northeast of China. By influencing the settlement and migration of microplastics, meteorological factors, such as relative humidity and wind speed, were identified as potential factors determining the distribution and characteristics of the detected microplastics. Our findings in this study, revealing the origin and fate of marine atmospheric microplastics, make an important contribution to our current understanding of the distribution and transmission of microplastics within the surveyed region and potentially worldwide.

Atmospheric microplastic deposition associated with GDP and population growth: Insights from megacities in northern China

Microplastic (MP) pollution is evolving into one of the most pressing environmental concerns worldwide. This study assessed the impact of economic activities on atmospheric MP pollution across 17 megacities in northern China, analyzing the correlation between the deposition flux of atmospheric MPs and variables such as city population, gross domestic product (GDP), and industrial structure. The results have shown that the MP pollution is obviously impacted by human activities related to increased GDP, population, as well as tertiary service sector, in which the MP pollution shows most close relationship with the GDP growth. Polypropylene, polyamide, polyurethane, and polyethylene were identified as the primary components of atmospheric MPs. The average particle size of MPs in atmospheric dustfall is 78.3 µm, and the frequency of MP particles increases as the particle size decreases. The findings highlight the complex relationship between socio-economic development and atmospheric MP accumulation, providing essential insights for the formulation of targeted emission reduction strategies.

Analysis of photocatalytic degradation of polyamide microplastics in metal salt solution by high resolution mass spectrometry

Microplastic pollution has become one of the most concerned focuses in the world. Among many treatment methods, photocatalysis is considered to be one of the most environmentally friendly methods. In this work, the photodegradation behavior of polyamide microplastics is studied by using polyamide 6 PA6) as model microplastics and FeCl3 as catalyst. It is hoped that the PA6 fiber can be effectively degraded by utilizing the strong oxidizing active species that can be produced after FeCl3 is irradiated in water. The results shows that PA6 fiber can be almost completely degraded after 10 days of irradiation in FeCl3 aqueous solution, indicating that it is promising to use this new method to solve the problem of PA6 type microplastics. In addition, the chain scission mechanism and degradation process of PA6 are analyzed in detail by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS), which provides a new insight for the study of polymer degradation mechanism.

Potential Effects of Environmental and Occupational Exposure to Microplastics: An Overview of Air Contamination

Microplastics (MPs) are now ubiquitous environmental contaminants that lead to unavoidable human exposure; they have received increasing attention in recent years and have become an emerging area of research. The greatest concern is the negative impacts of MPs on marine, fresh-water, and terrestrial ecosystems, as well as human health, to the extent that the World Health Organization (WHO) calls for increased research and standardized methods to assess exposure to MPs. Many countries and international organizations are implementing or proposing legislation in this regard. This review aims to summarize the current state of legislation, indoor and outdoor contamination, and potential human health risk due to exposure to airborne MPs, considering that occupational exposure to MPs is also becoming a growing area of concern. Even though research regarding MPs has continuously increased in the last twenty years, the effects of MPs on human health have been scarcely investigated, and toxicity studies are still limited and not directly comparable, due to the lack of standardized studies in this field.

Wearing face masks as a potential source for inhalation and oral uptake of inanimate toxins - A scoping review

BACKGROUND

From 2020 to 2023 many people around the world were forced to wear masks for large proportions of the day based on mandates and laws. We aimed to study the potential of face masks for the content and release of inanimate toxins.

METHODS

A scoping review of 1003 studies was performed (database search in PubMed/MEDLINE, qualitative and quantitative evaluation).

RESULTS

24 studies were included (experimental time 17 min to 15 days) evaluating content and/or release in 631 masks (273 surgical, 228 textile and 130 N95 masks). Most studies (63%) showed alarming results with high micro- and nanoplastics (MPs and NPs) release and exceedances could also be evidenced for volatile organic compounds (VOCs), xylene, acrolein, per-/polyfluoroalkyl substances (PFAS), phthalates (including di(2-ethylhexyl)-phthalate, DEHP) and for Pb, Cd, Co, Cu, Sb and TiO2.

DISCUSSION

Of course, masks filter larger dirt and plastic particles and fibers from the air we breathe and have specific indications, but according to our data they also carry risks. Depending on the application, a risk-benefit analysis is necessary.

CONCLUSION

Undoubtedly, mask mandates during the SARS-CoV-2 pandemic have been generating an additional source of potentially harmful exposition to toxins with health threatening and carcinogenic properties at population level with almost zero distance to the airways.

Mangrove plants are promising bioindicator of coastal atmospheric microplastics pollution

Plastics are commonly used by society and their break down into millimeter-sized bits known as microplastics (MPs). Due to the possibility of exposure, reports of them in atmospheric deposition, indoor, and outdoor air have sparked worry for public health. In tropical and subtropical regions all throughout the world, mangroves constitute a distinctive and significant type of coastal wetlands. Mangrove plants are considered to have the effect of accumulating sediment MPs, but the sedimentation of atmospheric MPs has not been reported. In this study, we illustrated the characteristics, abundance and spatial distribution of MPs in different species of mangrove leaves along the Seagull Island in Guangzhou. MPs samples from leaves in five species showed various shapes, colors, compositions, sizes and abundance. Acanthus ilicifolius had an average fallout rate of 1223 items/m2/day which has the highest abundance of MPs in all samples. Four shapes of MPs were found in all leaves surfaces including fiber, fragment, pellet, and film, with fiber is the most. The dominant types of MPs in all leaves were cellulose and rayon. Most of the total MPs size were smaller than 2 mm. Clearly, the microstructures of each species leaf surfaces had an impact on its ability to retain MPs. The plants rough blade surfaces and big folds or gullies caused more particles to accumulate and had a higher MPs retention capacity. Overall, our study contributes to a better knowledge of the condition of MPs pollution in atmosphere and the connection between leaves structure and the retention of MPs, which indicates that mangrove plants are promising bioindicator of coastal atmospheric MPs pollution.

Comparative study on physicochemical characteristics of atmospheric microplastics in winter in inland and coastal megacities: A case of Beijing and Shanghai, China

Atmospheric microplastics (MPs) have received global attention across various sectors of society due to their potential negative impacts. This study aims to understand the physicochemical characteristics of MPs in inland and coastal megacities for raising awareness about the urgent need to reduce plastic pollution. Laser Direct Infrared Imaging (LDIR) and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDX) techniques were employed to characterize atmospheric MPs in megacities (inland megacity Beijing and coastal megacity Shanghai) in China, focusing on their physicochemical characteristics, including compositional types, number concentration, morphology, size, possible sources, and potential health risks. The LDIR analysis identified sixteen different types of MPs present in the atmospheres of Beijing and Shanghai. The number concentration of atmospheric MPs in Beijing (3.0 items/m3) is 1.8 times that of Shanghai (1.7 items/m3). The study found that the variations in MP pollution between Beijing and Shanghai are influenced by the urban industrial structure and geographical location. Morphological analysis indicates that fragment MPs have the highest relative abundance in Beijing, while fibrous MPs dominate the atmosphere of Shanghai. Additionally, the study assessed the potential health risks of atmospheric MPs to urban residents. The results suggest that residents of Beijing face more severe health risks from atmospheric MPs compared to those in Shanghai. These findings underscore the urgency to address the issue of atmospheric MPs and provide crucial evidence for the formulation of relevant environmental and health policies.

Exploration of microplastic concentration in indoor and outdoor air samples: Morphological, polymeric, and elemental analysis

Microplastics are ubiquitously pervasive throughout the environment, but unlike aquatic and terrestrial microplastics, airborne microplastics have received less scientific attention. This study is the first of its kind to explicitly examine microplastics in the indoor and outdoor air (PM2.5) samples collected using active air samplers in Islamabad, Pakistan. The suspected synthetic particles were analyzed using ATR-FTIR, μ-Raman and SEM-EDX to categorize them based on their morphological characteristics, polymeric composition, and elemental makeup. Microplastics were found in all indoor and outdoor air samples, with indoor air samples (4.34 ± 1.93 items/m3) being significantly more contaminated than outdoor air samples (0.93 ± 0.32 items/m3) (P < 0.001). Among all the indoor air samples, samples taken from classroom (6.12 ± 0.51 items/m3) were more contaminated than samples taken from hallway (4.94 ± 0.78 items/m3) and laboratory (1.96 ± 0.44 items/m3). Fibers were found to be the prevalent shape type in indoor and outdoor airborne microplastics followed by fragments. Transparent- and black colored microplastic particles were predominant in both indoor and outdoor air samples. According to ATR-FTIR analysis, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polystyrene (PS) were the most prevalent polymer types in both indoor and outdoor environments. Results from μ-Raman analysis corroborated the presence of the polymers identified by ATR-FTIR. Morphological analysis of particles by SEM indicated signs of weathering on particles' surface i.e., grooves, breaks, shredded edges, pits etc. SEM-EDX of randomly chosen particles unraveled the presence of C and O as core elements, along with the presence of heavy metals at some spots due to foreign material adhering to their surface. Correlation analysis of environmental factors i.e., PM2.5, relative humidity, temperature, and wind speed with MPs abundance revealed non-significant relationships. The findings of this study call for further research on airborne MPs to better comprehend their dispersion, toxicity, interactions with other air pollutants, and attributable health risks.

Atmospheric microfibrous deposition over the Eastern Red Sea coast

The transport of microplastics through the atmosphere has been acknowledged as a significant route for their dispersion across different environments. Microplastics of fibrous shape often prevail in environmental samples, although their composition identification might be challenging and lead to an overestimation of plastic microfibers (MFs). Conversely, MFs of natural origin are rarely reported in microplastics studies despite the lack of consensus on the risks they may pose to the environment. In this study, airborne MFs collected in a sparsely populated residential area on the shore of the Eastern Red Sea were analyzed to investigate their abundance and polymer composition and assess their potential transport and deposition rates. The length of observed fibers ranged from 183 μm to 11,877 μm, with 3 % of fibers being >5 mm. The average length of MFs (< 5 mm) was 1378 ± 934 μm. Plastic MFs comprised 10 % of all identified MFs, with polyester being the most common plastic polymer (81.25 %). The mean abundance of airborne MFs was 0.9 ± 0.8 × 10-2 MFs m-3. The estimated mean atmospheric microfibrous deposition was 70 MFs m-2 d-1, with a component of 8 plastic MFs m-2 d-1. Based on the HYSPLIT backward trajectory analysis, fibers of local origin (estimated to travel approximately 25 km before sampling) were deposited at the sampling location. Air masses of northwestern origin traveling along the coast of the Eastern Red Sea dominated, potentially reducing the abundance of airborne MFs.

A comprehensive review of micro- and nano-plastics in the atmosphere: Occurrence, fate, toxicity, and strategies for risk reduction

Micro- and nano-plastics (MNPs) have received considerable attention over the past 10 years due to their environmental prevalence and potential toxic effects. With the increase in global plastic production and disposal, MNP pollution has become a topic of emerging concern. In this review, we describe MNPs in the atmospheric environment, and potential toxicological effects of exposure to MNPs. Studies have reported the occurrence of MNPs in outdoor and indoor air at concentrations ranging from 0.0065 items m-3 to 1583 items m-3. Findings have identified plastic fragments, fibers, and films in sizes predominantly <1000 μm with polyamide (PA), polyester (PES), polyethylene terephthalate (PET), polypropylene (PP), rayon, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polyacrylonitrile (PAN), and ethyl vinyl acetate (EVA) as the major compounds. Exposure through indoor air and dust is an important pathway for humans. Airborne MNPs pose health risks to plants, animals, and humans. Atmospheric MNPs can enter organism bodies via inhalation and subsequent deposition in the lungs, which triggers inflammation and other adverse health effects. MNPs could be eliminated through source reduction, policy/regulation, environmental awareness and education, biodegradable materials, bioremediation, and efficient air-filtration systems. To achieve a sustainable society, it is crucial to implement effective strategies for reducing the usage of single-use plastics (SUPs). Further, governments play a pivotal role in addressing the pressing issue of MNPs pollution and must establish viable solutions to tackle this significant challenge.

A critical review of the recent trends in source tracing of microplastics in the environment

Microplastics are found across the globe because of their size and ability to transport across environments. The effects of microplastics on the micro- and macro-organisms have brought out concern over the potential risk to human health and the need to regulate their distribution at the source. Control of microplastic pollution requires region-specific management and mitigation strategies which can be developed with the information on sources and their contributions. This review provides an overview of the sources, fate, and distribution of microplastics along with techniques to source-trace microplastics. Source-tracing approaches provide both qualitative and quantitive information. Since better outcomes have been produced by the integration of techniques like backward trajectory analysis with cluster analysis, the significance of integrated and multi-dimensional approaches has been emphasized. The scope of the plastisphere, heavy metal, and biofilm microbial community in tracing the sources of microplastics are also highlighted. The present review allows the researchers and policymakers to understand the recent trends in the source-tracing of microplastics which will help them to develop techniques and comprehensive action plans to limit the microplastic discharge at sources.

A study on managing plastic waste to tackle the worldwide plastic contamination and environmental remediation

Over the past 50 years, the emergence of plastic waste as one of the most urgent environmental problems in the world has given rise to several proposals to address the rising levels of contaminants associated with plastic debris. Worldwide plastic production has increased significantly over the last 70 years, reaching a record high of 359 million tonnes in 2020. China is currently the world's largest plastic producer, with a share of 17.5%. Of the total marine waste, microplastics account for 75%, while land-based pollution accounts for responsible for 80-90%, and ocean-based pollution 10-20% only in overall pollution problems. Even at small dosages (10 μg/mL), microplastics have been found to cause toxic effects on human and animal health. This review examines the sources of microplastic contamination, the prevalent reaches of microplastics, their impacts, and the remediation methods for microplastic contamination. This review explains the relationship between the community composition and the presence of microplastic particulate matter in aquatic ecosystems. The interaction between microplastics and emerging pollutants, including heavy metals, has been linked to enhanced toxicity. The review article provided a comprehensive overview of microplastic, including its fate, environmental toxicity, and possible remediation strategies. The results of our study are of great value as they illustrate a current perspective and provide an in-depth analysis of the current status of microplastics in development, their test requirements, and remediation technologies suitable for various environments.

There's something in the air: A review of sources, prevalence and behaviour of microplastics in the atmosphere

Literature regarding microplastics in the atmosphere has advanced in recent years. However, studies have been undertaken in isolation with minimal collaboration and exploration of the relationships between air, deposition and dust. This review collates concentrations (particle count and mass-based), shape, size and polymetric characteristics for microplastics in ambient air (m3), deposition (m2/day), dust (microplastics/g) and snow (microplastics/L) from 124 peer-reviewed articles to provide a holistic overview and analysis of our current knowledge. In summary, ambient air featured concentrations between <1 to >1000 microplastics/m³ (outdoor) and <1 microplastic/m³ to 1583 ± 1181 (mean) microplastics/m³ (indoor), consisting of polyethylene terephthalate, polyethylene, polypropylene. No difference (p > 0.05) was observed between indoor and outdoor concentrations or the minimum size of microplastics (p > 0.5). Maximum microplastic sizes were larger indoors (p < 0.05). Deposition concentrations ranged between 0.5 and 1357 microplastics/m²/day (outdoor) and 475 to 19,600 microplastics/m²/day (indoor), including polyethylene, polystyrene, polypropylene, polyethylene terephthalate. Concentrations varied between indoor and outdoor deposition (p < 0.05), being more abundant indoors, potentially closer to sources/sinks. No difference was observed between the minimum or maximum reported microplastic sizes within indoor and outdoor deposition (p > 0.05). Road dust concentrations varied between 2 ± 2 and 477 microplastics/g (mean), consisting of polyvinyl chloride, polyethylene, polypropylene. Mean outdoor dust concentrations ranged from <1 microplastic/g (remote desert) to between 18 and 225 microplastics/g, comprised of polyethylene terephthalate, polyamide, polypropylene. Snow concentrations varied between 0.1 and 30,000 microplastics/L, containing polyethylene, polyamide, polypropylene. Concentrations within indoor dust varied between 10 and 67,000 microplastics/g, including polyethylene terephthalate, polyethylene, polypropylene. No difference was observed between indoor and outdoor concentrations (microplastics/g) or maximum size (p > 0.05). The minimum size of microplastics were smaller within outdoor dust (p > 0.05). Although comparability is hindered by differing sampling methods, analytical techniques, polymers investigated, spectral libraries and inconsistent terminology, this review provides a synopsis of knowledge to date regarding atmospheric microplastics.

Toxicity and Biodistribution of Fragmented Polypropylene Microplastics in ICR Mice

Currently, polypropylene (PP) is used in various products, thus leading to high daily exposure in humans. Thus, it is necessary to evaluate the toxicological effects, biodistribution, and accumulation of PP microplastics in the human body. In this study, administration of two particle sizes of PP microplastics (approximately 5 and 10-50 µm) did not lead to any significant changes in several toxicological evaluation parameters, including body weight and pathological examination, compared with the control group in ICR mice. Therefore, the approximate lethal dose and no-observed-adverse-effect level of PP microplastics in ICR mice were established as ≥2000 mg/kg. Furthermore, we manufactured cyanine 5.5 carboxylic acid (Cy5.5-COOH)-labeled fragmented PP microplastics to monitor real-time in vivo biodistribution. After oral administration of the Cy5.5-COOH-labeled microplastics to the mice, most of the PP microplastics were detected in the gastrointestinal tract and observed to be out of the body after 24 h in IVIS Spectrum CT. Therefore, this study provides a new insight into the short-term toxicity, distribution, and accumulation of PP microplastics in mammals.

Spatial analysis of the influence on "microplastic communities" in the water at a medium scale

The issue of microplastics in freshwater has been growing in concern. Besides their abundance, the characteristics of microplastics are also important issues. The concept of "microplastic communities" has been utilized to assess differences in microplastic characteristics. In this study, we utilized the "microplastic community" approach to evaluate the impact of land use on microplastic characteristics in water at a provincial scale in China. The abundance of microplastics in water bodies in Hubei Province varied between 0.33 items/L and 5.40 items/L, with an average of 1.74 items/L. Microplastics were significantly more abundant in rivers than in lakes and reservoirs, and their abundance was negatively correlated with the distance from the nearest residential district of sampling sites. Similarities of microplastic communities were significantly different in mountainous and plain areas. Anthropogenic surfaces increased microplastic abundance and tended to decrease the size of microplastics, whereas natural vegetation had the opposite effect. The effect of land use on microplastic community similarity was greater than that of geographic distance. However, spatial scale limits the effect of various factors on microplastic community similarity. This study revealed the comprehensive influence of land use on microplastic characteristics in water and emphasized the importance of spatial scale in the study of microplastic characteristics.

Characterization and quantification of microplastics in indoor environments

Microplastics (MPs) have gradually attracted attention; however, people have paid limited attention to the existence of airborne microplastics, especially in indoor environments. In this study, we tracked microplastic deposition in offices, laboratories, dining halls, and dormitories. Results showed that the average microplastic abundance in the dormitory was the highest (14088.05 pcs/m³), followed by in the office (13097.13 pcs/m³), laboratory (7512.55 pcs/m³) and dining hall (4308.26 pcs/m³). The microplastics deposited at indoor environment were mostly dark, elongated and solid. The average particle size of the microplastics sampled at the four sampling points was 66.15 μm, but the size of the microplastics in the laboratory environment was smaller and more harmful. Airflow tests using air conditioners showed that turbulence increases the resuspension of microplastics. Our results also show that the frequency of human activities is one of the main factors leading to changes in the content of microplastics in indoor air, and turbulence caused by airflow will lead to the migration of microplastics in the indoor environment. In conclusion, indoor environments are prone to high microplastic concentration, which may pose certain potential risks to human health.

Transport of microplastics in the body and interaction with biological barriers, and controlling of microplastics pollution

Microplastics (MPs) are one novel environmental pollutant sized < 5 mm that is ubiquitously present in numerous environmental media and particularly susceptible to interact with various toxic chemicals. Importantly, MPs can enter the food chain, and are bio-enriched and bio-accumulated with trophic levels, eventually endangering ecosystems and human health. However, there need to be more understanding regarding the bio-interaction of MPs with the host, particularly for biological barriers. This review aimed to summarize the latest findings regarding the main exposure routes of MPs that generated health burdens on humans. Furthermore, their interactions with biological barriers that generate adverse health effects and the underlying mechanisms were also reviewed. Additionally, we provided a comprehensive overview of recent advances regarding the removing and controlling of MPs. Finally, we discussed the future directions for MPs hazard prevention to provide helpful information for regulating decision-making and guiding safer plastics applications.

From multi to single-particle analysis: A seasonal spectroscopic study of airborne particulate matter in Zaragoza, Spain

It is distinguished that deficient outdoor air quality is responsible for substantial health and climate issues. The aim of our study was to investigate the air quality in the city of Zaragoza (Spain) by characterizing atmospheric particulate matter (PM₁₀) during two seasons (winter and spring). PM₁₀ samples were collected in 2022 in quartz filters through a low-volume sampler and chemically analysed by complementary analytical techniques: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), Laser Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy (RS) and Field Emission Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (FESEM-EDS). Results have revealed, together with a temperature inversion phenomenon in winter, the presence of both natural (Al, Ca, Mg, Ti, Sr, Fe, etc.) and anthropogenic particles. The latter mainly formed by black carbon with an origin on fossil fuel combustion emissions. Additionally, chemical analyses of PM₁₀ filters showed the presence of three types of microplastics suspended in the air of the city: polyethylene terephthalate (PET), polyamides (PA) and polystyrene (PS). The results obtained from this research are of special interest to take into account for future air quality policies, particularly those with the aim of reducing air pollution in cities.

Microplastic Pollution: Chemical Characterization and Impact on Wildlife

Microplastics are small pieces of plastic that are less than 5 mm in size and can be found in most environments, including the oceans, rivers, and air. These small plastic particles can have negative impacts on wildlife and the environment. In this review of the literature, we analyze the presence of microplastics in various species of wildlife, including fish, birds, and mammals. We describe a variety of analytical techniques, such as microscopy and spectrometry, which identify and quantify the microplastics in the samples. In addition, techniques of sample preparation are discussed. Summary results show that microplastics are present in all the wildlife species studied, with the highest concentrations often found in fish and birds. The literature suggests that microplastics are widely distributed in the environment and have the potential to affect a wide range of species. Further research is required to fully understand the impacts of microplastics on wildlife and the environment.

Quantification and characterization of additives, plasticizers, and small microplastics (5-100 μm) in highway stormwater runoff

Highway stormwater (HSW) runoff is a significant pathway for transferring microplastics from land-based sources to the other surrounding environmental compartments. Small microplastics (SMPs, 5-100 μm), additives, plasticizers, natural, and nonplastic synthetic fibers, together with other components of micro-litter (APFs), were assessed in HSW samples via Micro-FTIR; oleo-extraction and purification procedures previously developed were optimized to accomplish this goal. The distribution of SMPs and APFs observed in distinct HSW runoff varied significantly since rainfall events may play a crucial role in the concentration and distribution of these pollutants. The SMPs' abundance varied from 11932 ± 151 to 18966 ± 191 SMPs/L. The dominating polymers were vinyl ester (VE), polyamide 6 (PA6), fluorocarbon, and polyester (PES). The APFs' concentrations ranged from 12825 ± 157 to 96425 ± 430 APFs/L. Most APFs originated from vehicle and tire wear (e.g., Dioctyl adipate or 5-Methyl-1H-benzotriazole). Other sources of these pollutants might be pipes, highway signs, packaging from garbage debris, road marking paints, atmospheric deposition, and other inputs. Assessing SMPs in HSW runoff can help evaluating the potential threat they may represent to receiving water bodies and air compartments. Besides, APFs in HSW runoff may be efficient proxies of macro- and 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 PM_2.5 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 PM_2.5, 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 PM_2.5 between the dry and wet seasons. The mean PM_2.5/PM₁₀ ratio was 0.576, implying that microplastics were partitioned more towards PM_2.5 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.