Release Of Microplastics Research Articles

Face masks: a COVID-19 protector or environmental contaminant?

Face masks, a prime component of personal protective equipment (PPE) items, have become an integral part of human beings to survive under the ongoing COVID-19 pandemic situation. The global population requires an estimated 130 billion face masks and 64 billion gloves/month, while the COVID-19 pandemic has led to the daily disposal of approximately 3.5 billion single-use face masks, resulting in a staggering 14,245,230.63kg of face mask waste. The improper disposal of face mask wastes followed by its mismanagement is a challenge to the scientists as the wastes create pollution leading to environmental degradation, especially plastic pollution (macro/meso/micro/nano). Each year, an estimated 0.15-0.39 million tons of COVID-19 face mask waste, along with 173,000 microfibers released daily from discarded surgical masks, could enter the marine environment, while used masks have a significantly higher microplastic release capacity (1246.62 ± 403.50 particles/piece) compared to new masks (183.00 ± 78.42 particles/piece). Surgical face masks emit around 59g CO2-eq greenhouse gas emissions per single use, cloth face masks emit approximately 60g CO2-eq/single mask, and inhaling or ingesting microplastics (MPs) caused adverse health problems including chronic inflammation, granulomas or fibrosis, DNA damage, cellular damage, oxidative stress, and cytokine secretion. The present review critically addresses the role of face masks in reducing COVID-19 infections, their distribution pattern in diverse environments, the volume of waste produced, degradation in the natural environment, and adverse impacts on different environmental segments, and proposes sustainable remediation options to tackle environmental challenges posed by disposable COVID-19 face masks.

Effect of ultrasonication conditions on polyethylene microplastics sourced from landfills: A precursor study to establish guidelines for their extraction from environmental matrices

Establishing concentration of microplastics (MPs), designated as CMP, in aqueous, semi-solid and solid samples originating from unscientifically created landfills/dumpsites (UCLDs) and engineered landfills (ELFs) is of utmost importance to assess their impact on the geoenvironment. However, the accuracy of CMP will be guided by the extraction efficiency of MPs from these samples. The extraction of MPs from semi-solid and solid samples of UCLDs/ELFs would be cumbersome, mainly due to their trapping in solid aggregates (including organic matter). Such aggregates need to be dispersed to release the MPs, which can be achieved through the assistance of ultrasonication (US) in the presence of an appropriate dispersing agent. However, mere dispersion of solid aggregates during the US might not result in the complete release of MPs adhered (AMPs) to MPs native (NMPs) to these samples. This is because MPs would adhere to the surface of the adjacent ones due to various physical-mechanical-thermal-chemical processes that prevail in landfills. Hence, guidelines for US-assisted extraction of MPs should be developed by considering an approach that would ensure (i) cleaning of NMPs’ surface and (ii) release of AMPs without damaging the former. This necessitates understanding the influence of US parameters such as energy applied (Eus), time (tus) and direct/indirect exposure of NMPs from landfills that would control CMP. In this context, the influence of above mentioned US parameters on the (i) surface cleaning of polyethylene NMPs and (ii) release of AMPs and their concentrations (CAMP) was investigated. It was observed that Eus equal to 500 kJ/L during the indirect method of US would result in surface cleaning of NMPs and complete release of AMPs without damaging the farmer’s structure. The present work acts as a precursor study to establish the guidelines for the US-assisted extraction of MPs in environmental samples. Also, a generalized relationship between Eus and CAMP, which can be employed to study the impact of landfill type on the release of MPs during the US was developed.

Microplastics in the urban atmosphere: Sources, occurrences, distribution, and potential health implications

Urbanization itself is a major and furthermost imperative contributor to the release of microplastics into the environments. As cities grow and develop, more plastic products are consumed and discarded, resulting in increased plastic pollution levels. Although researches on airborne microplastics (AMPs) in urban regions are scare, recent findings have shown high concentration of them in the air of residential areas. Textiles are the main source of airborne microplastics in indoor ambiance, while traffic-related plastic particles, textiles and agricultural and marine airborne microplastics appear to be responsible for polluting cities’ outdoor atmosphere. Local metrological situation, urban topography and physical features of plastic particles control the behavior, distribution and fate of airborne microplastics. Inhalation is the primary exposure route to airborne plastic particles and may induce toxicity in respiratory tract. Understanding these factors is crucial for developing effective strategies to mitigate their impact on human health and environment. Current work reviews the published literature on airborne microplastics in urban settings aiming at characterizing microplastics parent's materials, potential sources in both indoor and outdoor spaces, distribution and possible health impacts along with some further suggestions.

Characteristics and seasonal variation of microplastics in the wastewater treatment plant: The case of Bursa deep sea discharge

Microplastics (MPs) are an emerging pollutant that can be detected in all ecosystems, especially aquatic ecosystems. Wastewater treatment plants (WWTPs) are important point sources of MP release into the sea. In this study, the characteristics of MPs in wastewater and sludge samples taken from different units of WWTP in Bursa-Gemlik district for 12 months were investigated. Wastewater and sludge samples collected from 7 different points were classified as size, shape, color, and counted. The amount of MP in the influent and effluent of the WWTP, respectively; 107.1 ± 40.2 MP/L and 4.1 ± 1.1 MP/L. Although the MP removal efficiency of the WWTP is 96.17 %, approximately 74,825,000 MP is discharged into the Marmara Sea every day. The amount of MP in the sludge is 14.3 ± 7.1 MP/g. The amount of MP accumulated in 22tons of waste sludge formed daily in WWTP was calculated as 314,600,000 MP, and the annual accumulated amount was calculated as approximately 1.15 × 1011 MP. The MPs in the WWTP were mainly 1–0.5 mm in size. Fibers were the dominant MP shape in both the wastewater and sludge samples. Black and transparent were the dominant MP colors. Seven different polymer types of MPs were detected, which were mainly types of polyethylene, polypropylene, and polyethylene terephthalate. Despite the high removal efficiency in the investigated WWTP, it has been shown that it acts as an important source of MPs to the sea ecosystem due to the high discharge rates.

Removal of microplastics in wastewater by ceramic microfiltration

Microplastic (MP) pollution is a growing global concern affecting environmental water quality. Although primary and secondary treatment processes in conventional wastewater treatment plants (WWTPs) efficiently remove MPs, MPs <20 μm across are not removed effectively. The quality of final effluent should be enhanced by applying a tertiary treatment for reducing MP discharge from WWTPs. This study evaluated the effectiveness of ceramic membranes for this. Removal of MPs was assessed at laboratory scale by cross-flow filtration of a secondary wastewater effluent. The activated sludge process at a wastewater treatment plant removed MPs at moderate to high rates (45 %–98 %), and the ceramic membranes further removed >72 % of MPs. Although the activated sludge process removed variable rates of MPs, the total rates of removal by both processes was >96 %. This result suggests that the ceramic MF membrane treatment will contribute to stable MP removal.

Assessing the Release of Microplastics and Nanoplastics from Plastic Containers and Reusable Food Pouches: Implications for Human Health.

This study investigated the release of microplastics and nanoplastics from plastic containers and reusable food pouches under different usage scenarios, using DI water and 3% acetic acid as food simulants for aqueous foods and acidic foods. The results indicated that microwave heating caused the highest release of microplastics and nanoplastics into food compared to other usage scenarios, such as refrigeration or room-temperature storage. It was found that some containers could release as many as 4.22 million microplastic and 2.11 billion nanoplastic particles from only one square centimeter of plastic area within 3 min of microwave heating. Refrigeration and room-temperature storage for over six months can also release millions to billions of microplastics and nanoplastics. Additionally, the polyethylene-based food pouch released more particles than polypropylene-based plastic containers. Exposure modeling results suggested that the highest estimated daily intake was 20.3 ng/kg·day for infants drinking microwaved water and 22.1 ng/kg·day for toddlers consuming microwaved dairy products from polypropylene containers. Furthermore, an in vitro study conducted to assess the cell viability showed that the extracted microplastics and nanoplastics released from the plastic container can cause the death of 76.70 and 77.18% of human embryonic kidney cells (HEK293T) at 1000 μg/mL concentration after exposure of 48 and 72 h, respectively.

Plastic bottles for chilled carbonated beverages as a source of microplastics and nanoplastics

Carbonated beverages are characterized by low temperatures, multiple microbubbles, high pressure, and an acidic environment, creating ideal conditions for releasing contaminants from plastic bottles. However, the release patterns of microplastics (MPs) and nanoplastics (NPs) are poorly understood. We investigated the effects of plastic type, CO2 filling volume, temperature, sugar content, and additive on the leakage of MPs/NPs and heavy metals. Our results showed that polypropylene bottles released greater MPs (234±9.66 particles/L) and NPs (9.21±0.73 × 107 particles/L) than polyethylene and polyethylene terephthalate bottles. However, subjecting the plastic bottles to 3 repeated inflation treatments resulted in 91.65-93.18% removal of MPs/NPs. The release of MPs/NPs increased with increasing CO2 filling volume, driven by the synergistic effect of CO2 bubbles and pressure. After 4 freeze-thaw cycles, the release of MPs and NPs significantly increased, reaching 450±38.65 MPs and 2.91±0.10 × 108 NPs per liter, respectively. The presence of sugar leads to an elevation in MPs release compared to sucrose-free carbonated water, while the addition of additives to carbonated water exhibits negligible effects on MPs release. Interestingly, actual carbonated beverages demonstrated higher MPs concentrations (260.52±27.18-281.38±61.33 particles/L) than those observed in our well-controlled experimental setup. Our study highlights the non-negligible risk of MPs/NPs in carbonated beverages at low temperatures and suggests strategies to mitigate human ingestion of MPs/NPs, such as selecting appropriate plastic materials, high-pressure carbonated water pretreatment, and minimizing freeze-thaw cycles. Our findings provide insights for further study of the release patterns of the contaminants in natural environments with bubbles, pressure, low temperature, and freeze-thaw conditions.

High-Content Screening Discovers Microplastics Released by Contact Lenses under Sunlight.

The widespread use of plastic products leads to the ubiquity of microplastics in daily life, while the release of microplastics from long-used contact lenses has not been reported due to the limitations of conventional detection methods. Here, we established a new and rapid method to capture and count microplastics by using a high-content screening system. This method can simultaneously measure the diameter, area, and shape of each plastic particle, and the reliability and applicability of this method were verified with commercial microplastics. It is estimated that 90,698 particles of microplastics could be released from a pair of contact lenses during a year of wearing. The microplastics in the leachates were confirmed to be released from the contact lenses by scanning electron microscopy and Fourier transform infrared spectroscopy fingerprint analysis. Our study reveals an undiscovered pathway of microplastic direct exposure to humans, highlighting the urgent need to assess the potential health risks caused by eye exposure to microplastics.

Predicting microplastic masses in river networks with high spatial resolution at country level

Microplastics are a ubiquitous contaminant of natural waters, and a lot of field monitoring is currently performed. However, what is missing so far is a general understanding how emissions of microplastics are linked to environmental exposure, especially on larger geographic scales such as countries. Here we coupled a high-resolution microplastic release model with a fate model in rivers and lakes and parameterized it for Switzerland on a country scale to predict masses of microplastics in each river section for seven different polymers. The results show that catchment characteristics, for example, distribution of releases within the catchment, location and size of lakes or river connections, are as important as polymer properties such as density. There is no simple linear function of microplastic retention within a catchment in dependency of river length to the outlet. Instead, we found that different catchments cover a wide range of retained fractions for microplastics. Consequently, we argue that the availability and use of spatially distributed release data and performing modelling on high spatial resolution is of importance when estimating concentrations of microplastics in large areas such as countries.

The behavior of microplastics and nanoplastics release from UV-aged masks in the water

In this study, three types of disposable masks were exposed to ultraviolet (UV) irradiation to determine the effect of UV irradiation on the release of microplastics (MPs) and nanoplastic (NPs) from the masks. A kinetic model was used to investigate the mechanisms of M/NP release from the masks under UV irradiation. Results showed that UV irradiation exacerbated the damage to the structure of the mask over time. As the irradiation time increased, the middle layer of the mask was damaged first (15 d) and subsequently all layers of the mask were damaged (30 d). There was no significant difference in the quantity of M/NPs released from the treatment groups at different irradiance during a 5-d irradiation period. When the UV time reached 15 and 30 d, the highest quantity of M/NPs was released at 8.5 W/m2 followed by 4.9 W/m2, 15.4 W/m2, and 17.1 W/m2. Exponential equations fitted the release curve of M/NPs. The release quantity of M/NPs increases exponentially with increasing UV irradiation time, and the longer the irradiation time, the faster the rate of increase. Estimated release of 1.78 × 1017–3.66 × 1019 particles/piece of MPs and 8.23 × 1019–2.18 × 1022 particles/piece of NPs into the water when the masks are exposed to the real environment for 1–3 years.

Cutting Boards: An Overlooked Source of Microplastics in Human Food?

Plastic cutting boards are a potentially significant source of microplastics in human food. Thus, we investigated the impact of chopping styles and board materials on microplastics released during chopping. As chopping progressed, the effects of chopping styles on microplastic release became evident. The mass and number of microplastics released from polypropylene chopping boards were greater than polyethylene by 5-60% and 14-71%, respectively. Chopping on polyethylene boards was associated with a greater release of microplastics with a vegetable (i.e., carrots) than chopping without carrots. Microplastics showed a broad, bottom-skewed normal distribution, dominated by <100 μm spherical-shaped microplastics. Based on our assumptions, we estimated a per-person annual exposure of 7.4-50.7 g of microplastics from a polyethylene chopping board and 49.5 g of microplastics from a polypropylene chopping board. We further estimated that a person could be exposed to 14.5 to 71.9 million polyethylene microplastics annually, compared to 79.4 million polypropylene microplastics from chopping boards. The preliminary toxicity study of the polyethylene microplastics did not show adverse effects on the viability of mouse fibroblast cells for 72 h. This study identifies plastic chopping boards as a substantial source of microplastics in human food, which requires careful attention.

Insights into Anthropogenic Micro- and Nanoplastic Accumulation in Drinking Water Sources and Their Potential Effects on Human Health.

Anthropogenic microplastics (MPs) and nanoplastics (NPs) are ubiquitous pollutants found in aquatic, food, soil and air environments. Recently, drinking water for human consumption has been considered a significant pathway for ingestion of such plastic pollutants. Most of the analytical methods developed for detection and identification of MPs have been established for particles with sizes > 10 μm, but new analytical approaches are required to identify NPs below 1 μm. This review aims to evaluate the most recent information on the release of MPs and NPs in water sources intended for human consumption, specifically tap water and commercial bottled water. The potential effects on human health of dermal exposure, inhalation, and ingestion of these particles were examined. Emerging technologies used to remove MPs and/or NPs from drinking water sources and their advantages and limitations were also assessed. The main findings showed that the MPs with sizes > 10 μm were completely removed from drinking water treatment plants (DWTPs). The smallest NP identified using pyrolysis-gas chromatography-mass spectrometry (Pyr-GC/MS) had a diameter of 58 nm. Contamination with MPs/NPs can occur during the distribution of tap water to consumers, as well as when opening and closing screw caps of bottled water or when using recycled plastic or glass bottles for drinking water. In conclusion, this comprehensive study emphasizes the importance of a unified approach to detect MPs and NPs in drinking water, as well as raising the awareness of regulators, policymakers and the public about the impact of these pollutants, which pose a human health risk.

High levels of microparticles release from biodegradable polylactic acid paper cups compared with polyethylene-lined cups

Polylactic acid (PLA) is a popular replacement for conventional fossil-fuel based plastics products such as polyethylene (PE) due to its high biodegradability and recyclability. Previous studies confirmed that PLA microplastics (MPs) and PE MPs pose similar toxicity risks due to that MPs’ risk is primarily attributed to physical and indirect nutritional effects. Surprisingly, despite the widespread use, there have been very few studies of microparticles released from daily products made of biodegradable materials. We investigated release levels from eight single-use paper cups (SUPCs) lined with PLA and PE film. Under typical hot-beverage preparation conditions, the total number of particles released from PLA SUPCs was 4.2 times higher than that from PE SUPCs, with total numbers of 180,000 ± 31,000 and 43,000 ± 10,000 particles per litre, respectively. 22,000 ± 6,000 MPs were released per litre from PLA, which was 3.6 times the level of MPs released from PE SUPCs. In addition, significant levels of cellulose microfibres were released from PLA SUPCs, with quantities of 38,000 ± 31,000 microfibres per litre, while no such fibres were released from PE SUPCs. It should be noted that the levels of these particles may be underestimated due to the exclusion of nanoparticles (less than 0.8 μm, filter’s pore size), unidentified microparticles with high fluorescence backgrounds and attachments between different types of particles. In summary, a proportionately higher level of release of additive microparticles together with the release of cellulose microparticles are the key difference between biodegradable plastics like PLA and conventional plastic such as PE. Cellulose blending in manufacturing is likely related to higher MPs release from PLA cups than PE cups. Therefore, it is highly recommended to re-assess the manufacturing process, potential health and environmental risks of biodegradable plastic products as well as the formulation of related policies.

The escalated potential of the novel isolate Bacillus cereus NJD1 for effective biodegradation of LDPE films without pre-treatment

This study focused on the biodegradation of LDPE films using a novel isolate of Bacillus obtained from soil samples collected from a 20-year-old plastic waste dump. The aim was to evaluate the biodegradability of LDPE films treated with this bacterial isolate. The results indicated a 43% weight loss of LDPE films within 120 days of treatment. The biodegradability of LDPE films was confirmed through various testing methods, including BATH, FDA, CO2 evolution tests, and changes in total cell growth count, protein content, viability, pH of the medium, and release of microplastics. The bacterial enzymes, including laccases, lipases, and proteases, were also identified. SEM analysis revealed biofilm formation and surface changes in treated LDPE films, while EDAX analysis showed a reduction in carbon elements. AFM analysis demonstrated differences in roughness compared to the control. Furthermore, wettability increased and tensile strength decreased, confirming the biodegradation of the isolate. FTIR spectral analysis showed changes in skeletal vibrations, such as stretches and bends, in the linear structure of polyethylene. FTIR imaging and GC-MS analysis also confirmed the biodegradation of LDPE films by the novel isolate identified as Bacillus cereus strain NJD1. The study highlights the potentiality of the bacterial isolate for safe and effective microbial remediation of LDPE films.

Cross-sectional microstructural analysis to evaluate the crack growth pattern of weathered marine plastics

Fragmentation of degraded plastics and release of smaller secondary microplastics is usually attributed to the growth of environmental stress cracks. Analysis of crack patterns derived from chemical degradation can be useful not only for assessing the cause of plastic fracture and evaluating the useful lifetime of a product, but it can also potentially provide valuable information on the generation of microplastics. However, the literature with respect to microplastics generation is generally limited to surface observations of polypropylene and polyethylene. Here, we used ion-beam milling to prepare cross-sections of fragments of 15 plastic products made from five commodity plastics (polypropylene, polyethylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate) that were collected at two beaches in Japan, and then we examined the microstructures of those cross-sections by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. Crack growth in the depth direction was examined to provide insights into microplastic generation behavior. In all of the polypropylene samples, and some of the low-density polyethylene and polystyrene samples, cracks with a depth exceeding 100 μm from the sample surface were observed. Considering that crack growth causes fracture of degraded plastic and microplastic release, these observations suggest the release of sharp-edged microplastics from the crack fracture surface. In contrast, in the high-density polyethylene and polyvinyl chloride samples, crack growth was limited to within 20 μm of the sample surface, suggesting the release of irregularly shaped microplastics and additive particles. The present results suggest that the degradation behavior of plastic products in the depth direction is dependent on the type of plastic.

Evidence of microplastics release from polythene and paper cups exposed to hot and cold: A case study on the compromised kinetics of catalase

Microplastics (MPs) have become widespread in the modern world posing a hidden threat to the global environment. However, growing accumulation and devastating impact of MPs on human health and the environment have received least attention. In the current investigation, for the first time MPs have been identified which are released from the daily usable materials like polythene bags (PB) and paper cups (PC) in response to hot and cold water exposure at different time intervals. The impact of these MPs has been assessed on the major antioxidant enzyme, bovine liver catalase (BLC). The binding of MPs caused conformational changes in BLC by decreasing the α-helical content, which results in reduction of the enzymatic activity. Kinetics study revealed nearly ∼1.4-fold compromised catalytic efficiency of catalase in response to MPs. Nevertheless, hepatic catalase activity was also significantly decreased in presence of MPs. Further, materials like glass, porcelain, stainless steel, and high-grade plastics are discovered as greener alternatives to PB and PC.

Different weathering conditions affect the release of microplastics by masks.

A generation of microplastics caused by improper disposal of disposable masks has become a non-negligible environmental concern. In order to investigate the degradation mechanisms of masks and the release of microplastics under different environmental conditions, the masks are placed in 4 common environments. After 30 days of weathering, the total amount and release kinetics of microplastics released from different layers of the mask were studied. The chemical and mechanical properties of the mask were also discussed. The results showed that the mask released 25141±3543 particles/mask into the soil, which is much more than the sea and river water. The release kinetics of microplastics fit the Elovich model better. All samples correspond to the release rate of microplastics from fast to slow. Experiments show that the middle layer of the mask is released more than the other layers, and the amount of release was highest in the soil. And the tensile capacity of the mask is negatively correlated with its ability to release microplastics in the following order, which are soil > seawater > river > air > new masks. In addition, during the weathering process, the C-C/C-H bond of the mask was broken.

Quantitative analysis of polystyrene microplastic and styrene monomer released from plastic food containers

Since the COVID-19 outbreak, the use of disposable plastics has rapidly increased along with the amount of plastic waste. During fragmentation, microplastics and other chemical substances contained in plastics are released. These then enter humans through food which could be problematic considering their hazardous potential. Polystyrene (PS), which is widely used in disposable containers, releases large amounts of microplastics (MPs), but no studies have investigated the release mechanisms of PS-MPs and simultaneously exposed contaminants. Therefore, in this study, the effects of pH (3, 5, 7, and 9), temperature (20, 50, 80, and 100 °C), and exposure time (2, 4, 6, and 8 h) on MPs release were systematically examined. A quantitative/qualitative study of MPs and styrene monomers was performed using microscopy-equipped Fourier-transformed infrared spectroscopy and gas chromatography-mass spectrometry. The release of PS-MPs (36 items/container) and simultaneously exposed pollutants (SEP), such as ethylene glycol monooleate (EGM), was highest at pH 9, 100 °C, and 6 h, which was proportional to the test temperature and time. Under the same conditions, 2.58 μg/L of styrene monomer migrated to the liquid food simulants. The fragmentation was proceeded by oxidation/hydrolysis and accelerated by increased temperature and exposure time. The strong positive correlation between PS-MPs and SEPs releases at pH and temperature indicates that PS-MPs and SEPs follow the same release process. However, a strongly negative correlation between PS-MPs and styrene monomers at the exposed time shows that styrene migration does not follow the same release process, but does its partition coefficient.

The microscopic threat with a macroscopic impact: Microplastics along the southeast Florida reef tract

Microplastics decrease oceanic water quality and negatively impact marine life. This research quantified and classified marine plastic pollution along the Southeast Florida Reef Tract (SEFRT) to estimate the risk of microplastic damage to corals in this region. Surface and bottom water samples were collected at seven sites along the SEFRT over the course of six months and were analyzed for microplastic content. FTIR spectrophotometry was used to evaluate microplastic composition. Overall, seven plastic polymers were found across a total of 1204 microplastic items. Five contaminants were also identified, indicating that microplastics may be congregators of these hazardous contaminants. Significantly more total plastics were found in surface samples than in bottom samples, but plastic quantities were not significantly different when month, depth, and location were combined. Plastics were determined to have entered the ocean from multiple sources; in order to protect vulnerable reef ecosystems in this area, a two-factor approach is necessary to halt the release of microplastics into the ocean, including widespread plastic clean-up efforts and improvements to plastic waste management.

The Growth Inhibition of Polyethylene Nanoplastics on the Bait-Microalgae Isochrysis galbana Based on the Transcriptome Analysis.

The adverse effects of microplastics on microalgae species have been extensively studied, but their impact on the bait microalgae entering the food chain has not been well understood. This study investigated the cytological and physiological response of Isochrysis galbana to polyethylene microplastics (PE-MPs, 10 μm) and nanoplastics (PE-NPs, 50 nm). The results showed that PE-MPs had no significant impact on I. galbana, while PsE-NPs obviously inhibited cell growth, reduced chlorophyll content, and caused a decline in carotenoids and soluble protein. These changes in the quality of I. galbana could negatively affect its use as aquaculture feed. To understand the molecular response mechanism of I. galbana to PE-NPs, transcriptome sequencing was performed. The result revealed that the TCA cycle, purine metabolism, and some key amino acid syntheses were down-regulated by PE-NPs, while the Calvin cycle and fatty acid metabolism were up-regulated to tolerate PE-NP pressure. Microbial analysis showed that the bacterial community structure associated with I. galbana was significantly altered at the species level by PE-NPs. In conclusion, this study provides new insights into the physiological stress response caused by microplastic pollution based on transcriptome and bacterial community analysis. The findings highlight the need to mitigate the release of microplastics into the environment to prevent their harmful effects on aquatic ecosystems and will be helpful in understanding the impact of polyethylene nanoplastics on the bait microalgae.