Quantitation of Atmospheric Suspended Polystyrene Nanoplastics by Active Sampling Prior to Pyrolysis-Gas Chromatography-Mass Spectrometry

In vitro effects of aged low-density polyethylene micro(nano)plastic particles on human airway epithelial cells

Airborne micro(nano)plastic (MNP) pollution has emerged as a major global concern due to its increasingly worrying adverse health effects. Environmental weathering and UV irradiation of plastic waste, together with tire wear, generate airborne MNPs with irregular shapes and varied sizes, with low-density polyethylene (LDPE) being the predominant plastic type. However, knowledge of MNPs' toxicological effects remains scarce, as current in vitro research mainly focuses on commercial polystyrene beads. In this study, we investigated for the first time the toxicological effects of environmentally relevant aged LDPE MNPs on human bronchial epithelial cells (BEAS-2B). UV-aged LDPE fragments of irregular sizes and shapes were used to mimic real atmospheric particles, and BEAS-2B cells were exposed to 10-1000 μg/cm2 of LDPE MNPs. Our results showed that MNPs were internalized by BEAS-2B cells and promoted epithelial-to-mesenchymal transition (EMT), characterized by reduced β-catenin and increased vimentin expression, enhanced motility, and disturbed cell cycle. Moreover, exposure to aged LDPE MNPs significantly increased intracellular ROS levels and reduced cell proliferation rate at the highest dose. LDPE MNPs triggered oxidative stress in BEAS-2B cells through activation of the NRF2 signaling pathway, with impaired autophagic flux indicated by increased expression of p62 and LC3A/B. Importantly, LDPE MNP exposure significantly increased the secretion of pro-inflammatory mediators (CD62E, CD62P, ICAM-1, IL-6, IL-8), accompanied by suppressive effects on mitochondrial respiration and glycolytic function at 1000 μg/cm2. Taken together, our findings suggest that inhalation of LDPE MNPs could impact the morphology and function of the human airway epithelium and respiratory health in general.

A critical review of the ecotoxic effects of microplastics on aquatic, soil and atmospheric ecosystems and current research challenges

The extensive use of plastics has brought unparalleled convenience to human social development. However, this has also led to severe environmental and health challenges, with microplastic (MP) pollution emerging as one of the most pressing issues. As ubiquitous environmental pollutants, MPs persist in ecosystems and pose potential risks to both ecological and human health. Studies reveal that MPs impact aquatic, soil, and atmospheric ecosystems by altering their physicochemical properties and causing toxicological harm to resident organisms. Despite these findings, a comprehensive assessment and analysis of MP impacts, especially on atmospheric ecosystems, remains lacking. Similarly, the environmental biotoxicity mechanisms associated with MPs are yet to be systematically described. This review provides an in-depth discussion of the sources and characteristics of MPs, laying the background for elaborating their ecological effects. Current knowledge on MP ecotoxicity in aquatic, soil, and atmospheric ecosystems is then synthesized. Potential molecular mechanisms of biotoxicity are explored. Oxidative stress, inflammatory responses, and metabolic signaling pathway impairment are considered important pathways through which MPs induce toxic injury in environmental animals and have received widespread attention. Additionally, this review emphasizes the challenges faced in studying ecotoxic effects and mechanisms of MPs, such as the lack of reliable detection of environmental MPs and in-depth mining of relevant data, and suggests possible directions for future research. Although progress has been made, significant knowledge gaps remain. Addressing these gaps is critical if effective strategies are to be developed to reduce the environmental and health risks posed by MPs.

Characterizing Atmospheric Oxidation and Cloud Condensation Nuclei Activity of Polystyrene Nanoplastic Particles

Nanoplastic particles (NPPs) are emerging anthropogenic pollutants and have been detected in urban, rural, and remote areas. Characterizing the lifetime, fate, and cloud-forming potential of atmospheric NPPs improves our understanding of their environmental processes and climate impacts. This study provides the first quantified heterogeneous reaction rate and lifetime of polystyrene (PS) NPPs against common atmospheric oxidants. The atomized PS NPPs were introduced to a Potential Aerosol Mass (PAM) oxidation flow reactor with ·OH exposure of 0 to 1.5 × 1012 molecules cm-3 s, equivalent to atmospheric exposure from 0 to 18 days, assuming an ambient ·OH concentration of 1 × 106 cm-3. The decay of the PS mass concentration was quantified by monitoring tracer ions, C6H6+ (m/z 78) and C8H8+ (m/z 104), by using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The pseudo-first-order rate constant of PS particles reacting with ·OH, kOH, was determined to be (3.2 ± 0.7) × 10-13 cm3 molecule-1 s-1, equivalent to a half-lifetime of a few hours to ∼80 days in the atmosphere, depending on particle sizes and hydroxyl radical concentrations. The hygroscopicity of 100 nm PS NPPs at different ·OH exposure levels was quantified using a cloud condensation nuclei counter (CCNC), showing a twofold increase of hygroscopicity parameter upon 27 days of atmospheric photooxidation.

Phosphorescent Naphthalene-Doped Carbon Nitride Quantum Dots for Selective Detection of Polyamide Microplastics

Fluorescent dye labeling is a visual method for the detection of microplastics (MPs). However, the interference from the background fluorescence in complex environmental samples results in overestimation of the MP number, and the nonspecific fluorescent dye cannot selectively detect a single type of MPs. Herein, phosphorescent naphthalene-doped carbon nitride quantum dots (NDCNQDs) were prepared via incomplete condensation of urea with 1,5-diaminonaphthalene at 250 °C and used as a specific dye to stain polyamide (PA) MPs via hydrogen bonding. A phosphorescence imaging method for the selective detection of PA MPs was proposed. Benefitting from the long lifetime of phosphorescence, the interference from the background fluorescence in environmental samples was avoided. The recoveries for PA MPs in pond water samples and pond mud samples were 91.2-108.4%. PA MPs in environmental samples (e.g., streamwater, sediment, house dust) were analyzed without complicated pretreatment. This work provides a strategy for the specific detection of PA MPs in environmental samples.

Micro(nano)plastics (< 4 μm): An important but ignored concern during intravenous infusion

Micro(nano)plastics (MNPs) have been observed in human blood, and atheroma, and they are associated with cardiovascular events. However, their sources remain poorly understood. Intravenous infusion products (IVIPs) might introduce MNPs directly into the human blood, which threatens health, but they remain unknown. Herein, simulated intravenous therapy was performed to detect multiple MNPs with sizes < 4 μm released from commonly used IVIPs through established analytical methods such as modified Raman spectroscopy and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDS). Results showed that polypropylene- and polyvinyl chloride- MNPs were identified from six different IVIPs during intravenous therapy via modified Raman spectroscopy. Furthermore, SEM-EDS analysis observed irregular or near-spherical MNPs ranging from 10 nm to 3.6 μm, with a number concentration of (5.82 ± 0.86) × 104 items/L during intravenous therapy. These MNPs could directly enter the human blood with infusion fluids via intravenous therapy, posing serious risks to human health and affecting the safe use of IVIPs. Overall, these findings revealed that intravenous therapy could introduce MNPs, especially nanoplastics, directly into the human blood, highlighting the importance of considering MNPs in evaluating the safety of IVIPs.

Plastic Smell: A Review of the Hidden Threat of Airborne Micro and Nanoplastics to Human Health and the Environment

Airborne micro and nanoplastics (MPs/NPs) are a growing issue due to their possible health hazards. Since the current bibliography lacks a thorough evaluation, this review examines the sources, environmental dynamics, and health impacts of airborne MPs/NPs. Through atmospheric transport processes, these neo-pollutants spread around the world after being released, potentially settling in urban and remote areas. This review is the first to compare active and passive aerosol sampling methods, and microscopy, thermochemical, and spectroscopy analytical techniques, with a focus on their limitations in precisely quantifying micro-nanoscale plastic particles. It also draws attention to the potential toxicological effects of inhaled MPs/NPs, which can lead to oxidative stress, respiratory inflammation, and other negative health consequences. This review concludes by examining how airborne MPs/NPs may worsen their ecological impact by serving as carriers of hazardous chemicals and microbial pollutants. Despite growing awareness, there still are many unanswered questions, especially about the impact of long-term exposure and how atmospheric conditions affect the spread of MPs/NPs. The aim of this review was to bring attention to the issue of airborne MP/NP effects and to promote the development of advanced monitoring systems, a new multidisciplinary scientific field for the study of these novel pollutants, and global regulatory frameworks.

Quantification of the Uptake and Biodistribution of Nanoplastics in Escherichia coli

Nanoplastics (NPs) are prevalent in the environment, posing risks to ecosystems and human health. While research into their effects on bacterial activity has increased, the mechanisms underlying NP-bacteria interactions─specifically whether NPs penetrate cells or adhere to the cell surface─remain poorly understood. This knowledge gap largely stems from the absence of quantitative analytical methods. Herein, we developed a novel approach combining lysozyme treatment with pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) to differentiate between intracellular and cell wall-bound NPs in Escherichia coli (E. coli) quantitatively. The method involves selective removal of the bacterial cell wall using lysozyme, protein corona-induced extraction to enrich cell wall-bound NPs, and hydrogen peroxide digestion to eliminate protoplast interference before Py-GC/MS analysis. Validation with europium (Eu)-labeled NPs, quantified by inductively coupled plasma mass spectrometry (ICP-MS), confirmed the method's accuracy and reliability. Using this approach, we found that after NP exposure, only a small fraction (9.6-10.5%) of NPs penetrated E. coli cells, while the majority (36.9-63.8%) adhered to the cell surface. Transmission electron microscopy further corroborated these findings. Consequently, this work provides a robust tool for the quantification of NP uptake and biodistribution in bacterial systems, advancing our understanding of NP-microorganism interactions and their environmental implications.

Quantification of micro- and nano-plastics in atmospheric fine particles by pyrolysis-gas chromatography-mass spectrometry with chromatographic peak reconstruction

The effects of micro- and nano-plastics (MNPs) on human health are of global concern because MNPs are ubiquitous, persistent, and potentially toxic, particularly when bound to atmospheric fine particles (PM2.5). Traditional quantitative analysis of MNPs by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) is often inaccurate because of false positive signals caused by similar polymers and organic compounds. In this study, a reliable analytical strategy combining HNO3 digestion and chromatographic peak reconstruction was developed to improve the precision of pyrolysis-gas chromatography-mass spectrometry analysis of multiple MNPs bound to PM2.5. The optimized HNO3 digestion method using high-pressure oxidation conditions effectively removed organic matter within two hours, giving recovery rates of 64 %-110 % for eight target MNPs. The chromatographic peak reconstruction procedure minimized interferences caused by similar polymers and achieved high accuracy (101 % ± 10 %) for polyvinyl chloride, polyethylene terephthalate, and polystyrene, whose concentrations are often overestimated due to overlapping pyrolysis products. Quantification uncertainties for MNPs in real PM2.5 samples were up to 52 % lower using the new method than using previous methods. The method was validated using PM2.5 from urban Guangzhou. The total concentrations of the eight target MNPs in the PM2.5 samples were 100-990 ng/m3 (median 277 ng/m3) and the dominant MNPs were polyethylene, polyethylene terephthalate, and polyvinyl chloride, which contributed > 90 % of the MNPs. The new method allows the robust and accurate quantification of MNPs in atmospheric fine particles and will be useful in future studies on the environmental behaviors of MNPs and risks they pose.

Aerosol mass concentrations and dry/wet deposition of atmospheric microplastics at a remote coastal location in New Zealand

This study quantified airborne microplastic concentrations by mass and number counts using both active and passive sampling at a remote coastal location in Southern New Zealand. Seven polymers were quantified using pyrolysis gas chromatography mass spectrometry (Pyr-GC/MS) in atmospheric samples, finding that plastics comprised at least 0.14 % of total suspended particulate mass at the remote coastal site. Air parcel back trajectories suggest that airborne microplastics at the site, observed at an average concentration of 65 ± 6 ng m-3, have origins from the Southern Ocean. Additionally, the results demonstrate that reporting atmospheric deposition of microplastics by number counts may underestimate the true amount of plastics present in samples, as size limitations associated with microscopic imaging do not allow for quantification of the most abundant sizes and types of environmental microplastics. With current uncertainties related to aerosol formation in the Southern Ocean and the associated impacts on climate forcing, further research is urgently needed on the production of airborne microplastics originating from the Southern Ocean, a possible microplastic reservoir.

Determination of 4-tert-butyl pyrocatechol content in styrene with high accuracy using a chromatographic device under safe conditions: a laboratory study

A novel analytical method was developed for the determination of 4-tert-butylpyrocatechol (TBC) in styrene. Various measurement methods were compared. TBCs were analyzed using a straightforward method, which had significantly less contamination, and no additional chemicals were added to the solution. A non-polar column and temperature programming was then followed by an analysis and quantification of the final product to achieve this objective. In the range of 5 to 40 mg/kg (R2 ≥ 0.9999), the TBC peak area demonstrated notable linearity. Using the same technique, the obtained results were compared to TBC-containing real, standard, and proficiency test (PT) samples. This method showed the limit of detection (LOD) of 0.04-0.56 mg/kg and the limit of quantification (LOQ) of 0.15-1.96 mg/kg. The relative standard deviation (n = 15) was statistically lower than 10%. With fewer reagent requirements, contamination, and exposure to styrene due to carcinogenicity, this technique enables easy analysis of large amounts of samples. Therefore, it is possible to use it as a cutting-edge and creative method to measure the TBC content of styrene, particularly during routine analysis.

An Atmospheric Chemistry Perspective on Airborne Micro- and Nanoplastic Particles

Micro- and nanoplastic particles (MNPPs) are emerging pollutants with significant environmental impacts due to their persistence, increasing concentrations, and potential health risks. Most MNPP studies have focused on identifying, quantifying, and assessing their ecotoxicological impacts in water or soil. However, the atmosphere is crucial in transporting and chemically transforming MNPPs. Further, well-established aerosol particle characterization techniques are underutilized and inconsistently applied in existing atmospheric MNPP studies. This perspective synthesizes the existing literature and addresses future research needs unique to atmospheric MNPPs, highlighting the need to bridge the microplastics and atmospheric aerosol communities to better understand their sources, chemical transformations, transport mechanisms, as well as their health effects and ecological impacts, which differ from those in soil and water. Advancing research in these areas requires standardized methods and a multidisciplinary approach to comprehensively assess MNPP interactions across environmental compartments, providing essential insights into their environmental fate and risks.

Nanoplastics as Gene and Epigenetic Modulators of Endocrine Functions: A Perspective

Nanoplastics (NPs) represent a major challenge in environmental contamination resulting from the physical, chemical, and biological degradation of plastics. Their characterization requires advanced and expensive methods, which limit routine analyses. The biological effects of NPs depend on their chemical and physical properties, which influence toxicity and interactions with biological systems. Studies in animal models, such as Daphnia magna and Danio rerio, show that NPs induce oxidative stress, inflammation, DNA damage, and metabolic alterations, often related to charge and particle size. NPs affect endocrine functions by acting as endocrine disruptors, interfering with thyroid and sex hormones and showing potential transgenerational effects through epigenetic modifications, including DNA hyper- and hypomethylation. Behavioral and neurofunctional alterations have been observed in Danio rerio and mouse models, suggesting a link between NP exposure and neurotransmitters such as dopamine and serotonin. Despite limited human studies, the presence of NPs in breast milk and placenta underscores the need for further investigation of health effects. Research focusing on genetic and epigenetic markers is encouraged to elucidate the molecular mechanisms and potential risks associated with chronic exposure.

Size-Resolved SERS Detection of Trace Polystyrene Nanoplastics via Selective Electrosorption

Microplastics and nanoplastics are emerging contaminants that pose a threat to the environment and human. Spectroscopic technologies are advantageous in analyzing nanoplastics, but it is challenging to selectively detect nanoplastics with different size thresholds. In this work, the hyphenated method of electrosorption and surface-enhanced Raman spectroscopy (ES-SERS) was developed for the simple, rapid, and size-resolved analysis of trace polystyrene (PS) nanoplastics from 20 to 300 nm. A rough silver was used as both the working electrode for electrosorption and the substrate for the SERS response. By applying a positive electric potential to the rough silver, the PS nanoplastics accelerated toward the silver surface and were adsorbed tightly at the SERS "hot spot" inside the rough silver nanostructure. The proposed ES-SERS method achieved a detection limit of 100 ng/L for 300 and 100 nm PS, 50 ng/L for 50 nm PS, and 30 ng/L for 20 nm PS nanoplastics. It is worth noting that smaller nanoplastics typically exhibit larger analytical enhancement factor values in ES-SERS. According to the difference in electromigration behavior of PS in various sizes, PS nanoplastics under a certain size can be selectively enriched and detected by controlling the electrosorption time. The ES-SERS method was successfully demonstrated for detecting nanoplastics released from the lids of disposable beverage cups. This work opens up new possibilities for size-resolved analysis of nanoplastics.

Differential Leaf-to-Root Movement, Trophic Transfer, and Tissue-Specific Biodistribution of Metal-Based and Polymer-Based Nanoparticles When Present Singly and in Mixture

The transfer of nanoparticles (NPs) through the terrestrial food chain via foliar uptake presents poorly understood risks, especially in scenarios involving copollution and plant translocation. Herein, we exposed the radishes to single and mixed foliar doses of CeO2 NPs and deuterated polystyrene (DPS), investigating the trophic transfer of NPs from radish shoots/roots to snails. Compared to single treatments, mixture treatments increased Ce uptake by plants but had no effect on DPS uptake. Additionally, mixture treatments did not affect the movement of Ce and DPS from shoots to roots. Under NP mixture exposure, trophic transfer efficiencies (TTF) for Ce (2.09 × 10-2) and DPS (2.54 × 10-2) significantly decreased in shoot-feeding snails. In root-feeding snails, TTF for Ce (3.32 × 10-1) also showed a significant decrease, while TTF for DPS remained unchanged. Mixture treatments exhibited differential impacts on different snail body parts, particularly leading to biomagnification of DPS in the digestive glands and soft tissues (TTF > 1) of snails consuming roots exposed to mixtures. Both CeO2 and DPS displayed a sudden increase in assimilation efficiency following translocation to the roots. This study provides insights into changes during trophic transfer due to coexposure and plant translocation processes associated with nanoparticles, enhancing our comprehension regarding their environmental risks.

Micro- and nano-plastics in the atmosphere: A review of occurrence, properties and human health risks

The ubiquitous occurrence of micro/nano plastics (MNPs) poses potential threats to ecosystem and human health that have attracted broad concerns in recent decades. Detection of MNPs in several remote regions has implicated atmospheric transport as an important pathway for global dissemination of MNPs and hence as a global health risk. In this review, the latest research progress on (1) sampling and detection; (2) origin and characteristics; and (3) transport and fate of atmospheric MNPs was summarized. Further, the current status of exposure risks and toxicological effects from inhaled atmospheric MNPs on human health is examined. Due to limitations in sampling and identification methodologies, the study of atmospheric nanoplastics is very limited today. The large spatial variation of atmospheric MNP concentrations reported worldwide makes it difficult to compare the overall indoor and outdoor exposure risks. Several in vitro, in vivo, and epidemiological studies demonstrate adverse effects of immune response, apoptosis and oxidative stress caused by MNP inhalation that may induce cardiovascular diseases and reproductive and developmental abnormalities. Given the emerging importance of atmospheric MNPs, the establishment of standardized sampling-pretreatment-detection protocols and comprehensive toxicological studies are critical to advance environmental and health risk assessments of atmospheric MNPs.

Quantifying the Chemical Composition and Real-Time Mass Loading of Nanoplastic Particles in the Atmosphere Using Aerosol Mass Spectrometry

Plastic debris, including nanoplastic particles (NPPs), has emerged as an important global environmental issue due to its detrimental effects on human health, ecosystems, and climate. Atmospheric processes play an important role in the transportation and fate of plastic particles in the environment. In this study, a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was employed to establish the first online approach for identification and quantification of airborne submicrometer polystyrene (PS) NPPs from laboratory-generated and ambient aerosols. The fragmentation ion C8H8+ is identified as the major tracer ion for PS nanoplastic particles, achieving an 1-h detection limit of 4.96 ng/m3. Ambient PS NPPs measured at an urban location in Texas are quantified to be 30 ± 20 ng/m3 by applying the AMS data with a constrained positive matrix factorization (PMF) method using the multilinear engine (ME-2). Careful analysis of ambient data reveals that atmospheric PS NPPs were enhanced as air mass passed through a waste incinerator plant, suggesting that incineration of waste may serve as a source of ambient NPPs. The online quantification of NPPs achieved through this study can significantly improve our understanding of the source, transport, fate, and climate effects of atmospheric NPPs to mitigate this emerging global environmental issue.

Micro(nano)plastics in the Human Body: Sources, Occurrences, Fates, and Health Risks

The increasing global attention on micro(nano)plastics (MNPs) is a result of their ubiquity in the water, air, soil, and biosphere, exposing humans to MNPs on a daily basis and threatening human health. However, crucial data on MNPs in the human body, including the sources, occurrences, behaviors, and health risks, are limited, which greatly impedes any systematic assessment of their impact on the human body. To further understand the effects of MNPs on the human body, we must identify existing knowledge gaps that need to be immediately addressed and provide potential solutions to these issues. Herein, we examined the current literature on the sources, occurrences, and behaviors of MNPs in the human body as well as their potential health risks. Furthermore, we identified key knowledge gaps that must be resolved to comprehensively assess the effects of MNPs on human health. Additionally, we addressed that the complexity of MNPs and the lack of efficient analytical methods are the main barriers impeding current investigations on MNPs in the human body, necessitating the development of a standard and unified analytical method. Finally, we highlighted the need for interdisciplinary studies from environmental, biological, medical, chemical, computer, and material scientists to fill these knowledge gaps and drive further research. Considering the inevitability and daily occurrence of human exposure to MNPs, more studies are urgently required to enhance our understanding of their potential negative effects on human health.

Toxicity Mechanisms of Nanoplastics on Crop Growth, Interference of Phyllosphere Microbes, and Evidence for Foliar Penetration and Translocation

Despite the increasing prevalence of atmospheric nanoplastics (NPs), there remains limited research on their phytotoxicity, foliar absorption, and translocation in plants. In this study, we aimed to fill this knowledge gap by investigating the physiological effects of tomato leaves exposed to differently charged NPs and foliar absorption and translocation of NPs. We found that positively charged NPs caused more pronounced physiological effects, including growth inhibition, increased antioxidant enzyme activity, and altered gene expression and metabolite composition and even significantly changed the structure and composition of the phyllosphere microbial community. Also, differently charged NPs exhibited differential foliar absorption and translocation, with the positively charged NPs penetrating more into the leaves and dispersing uniformly within the mesophyll cells. Additionally, NPs absorbed by the leaves were able to translocate to the roots. These findings provide important insights into the interactions between atmospheric NPs and crop plants and demonstrate that NPs' accumulation in crops could negatively impact agricultural production and food safety.

Direct entry of micro(nano)plastics into human blood circulatory system by intravenous infusion

Understanding the pathways of human exposure to micro(nano)plastics (MNPs) is crucial for assessing their health impacts. Intravenous infusion can induce MNPs direct entry into the human blood, posing serious risks on human health, but remains unclear. Herein, we developed comprehensive analytical methods to detect polyvinyl chloride (PVC) MNPs down to 20 nm, and found about 0.52 μg equal to 105-1011 particles of PVC-MNPs released from intravenous infusion products (IVIPs) during each intravenous infusion of 250 mL injection. The released amounts of MNPs from IVIPs were dependent on the plastic materials, and the injection volume and composition. These findings indicated that the released MNPs should be directly introduced into the human blood circulatory system, causing serious impacts on human health. Our study reveals a previously ignored but important pathway of human exposure to MNPs, and calls for further research on the potential risks of these MNPs on human health.