Plastic Fragments Research Articles

Quantification, characterization, and source identification of macro- and mesoplastics in the water column of Rivers Sabaki and Tana.

Five sampling campaigns were conducted in the water columns of River Sabaki and Tana in Kenya, Between October 2021 and January 2023, covering a 1-year cycle, at four sites in River Sabaki (2.5km, 3.05km, 3.51km, and 4.52km) and River Tana (1.5km, 1.8km, 2.0km, and 2.5km) distant from the river mouth. The ebb and flood tides were sampled to calculate net plastic litter fluxes. Two 6350-µm seine nets were deployed in two replicates per sampling point. Factor and cluster analysis were used to investigate plastic litter sources for both rivers. The influences of rainfall on plastic abundance and mass were explored using permutational linear models. A total of 15,318 plastic litter items weighing 1.37kg were recorded in River Sabaki, and 3741 plastic litter items weighing 0.95kg in River Tana. The top ten captured plastic litter types sorted by abundance and mass were mostly plastic fragments. The annual net plastic litter flux to the ocean through River Sabaki amounted to 1,277,120.63 items year-1 by abundance and 22.30kgyear-1 by mass. For River Tana, the same fluxes were 207,550.76 items year-1, and 28.09kgyear-1, respectively. In River Sabaki, significant impacts of rainfall on plastic abundance and mass were found. River Sabaki's pollution sources included upstream reaches, fishing activities, and littering by locals and tourists. River Tana's major pollution sources were illegal dumpsites, littering, fishing, and recreational activities. This research can guide combat plastic pollution in the rivers and ultimately the ocean.

Polyethylene Terephthalate Microplastic Exposure Induced Reproductive Toxicity Through Oxidative Stress and p38 Signaling Pathway Activation in Male Mice

Polyethylene terephthalate (PET) is a type of polymer plastic that is often used to make plastic bags, bottles, and clothes. However, the waste of such plastic products is decomposed into microplastics (MPs), which are plastic fragments smaller than 5 mm, by various external forces such as wind, UV radiation, mechanical wear, and biodegradation. PET MPs have been widely detected in the environment and human tissue samples; however, the toxicity and mechanism of PET MPs in mammals are still unclear. In this study, we investigated the male reproductive toxicity of PET MPs and their underlying mechanism. A total of 80 male mice were orally exposed to 0.01, 0.1, and 1 mg/d of PET MPs (with a diameter of 1 μm) for 42 days. The results showed that 1 μm PET MPs induced different degrees of pathological damage to testicular tissues, decreased sperm quality, and increased the apoptosis of spermatogenic cells via oxidative stress and p38 signaling pathway activation. To further illustrate and verify the mechanistic pathway, oxidative stress was antagonized using N-acetylcysteine (NAC), and the activation of the p38 signaling pathway was blocked using SB203580. The results revealed that the male reproductive injury effects after exposure to PET MPs were significantly ameliorated. Specifically, the testicular tissue lesions were relieved, the sperm quality improved, and the apoptosis of spermatogenic cells decreased. These results demonstrated that PET MP exposure induced male reproductive toxicity through oxidative stress and the p38 signaling pathway. This study provides new insights into the reproductive toxicity of MPs in males, as well as valuable references for public health protection strategies.

Assessing on-site plastics fragmentation: Linking macroplastics litter to microplastics pollution in vegetable fields

This study proposes a novel approach to determine whether farmers act as a pollution source of microplastics through macroplastic mismanagement or if they are temporary hosts of in-transit microplastics. Using a case-study approach, it was hypothesized that 90 % of soil microplastics would trace back to macroplastic waste mismanaged by farmers. To determine the amount of soil microplastics, linear transects were established and microplastic litter was counted and classified. Additionally, composite soil samples were used to count and colour-classify microplastics. The Kendall correlation was used to differentiate between the colour ranks of macro- and microplastics to discriminate between plastic on-site fragmentation or exogenous plastic pollution. For this, 37 vegetable farms in central Chile were assessed after the growing season. Farms showed lower microplastic counts than previously reported for similar productive conditions (3.68 ± 3.28 u/kg). A median colour correlation of 0.43 (IQR = 0.18–0.55) was observed between macro- and microplastics. Only in 25 % of the studied fields did on-site plastic fragmentation predominate over exogenous plastic pollution. The applied approach is simple to implement and does not require specialized laboratory equipment. We hope that the proposed methodology will serve in environmental monitoring to evaluate adherence to good agricultural practices and to guide pollution-prevention measures.

Microplastic levels in the indoor air of buildings based on plastic waste recycling in Indonesia

Introduction: Microplastics are a new type of contamination in the environment caused by plastic fragmentation and degradation. The generation of plastic waste increases every year, therefore efforts are made to recycle it into building materials. It is unclear how building use resulting from recycling plastic waste affects the development of microplastics in the atmosphere. The purpose of this study is to determine the airborne concentrations of microplastics in buildings constructed from recycled plastic waste. Materials and methods: The study measured microplastic levels in the air for 30 days in a miniature building made from plastic waste. Samples taken during the dry season in Indonesia in 2023. Air sampling is carried out by passive method. Visual observation of the shape, and amount of microplastics using a microscope. Results: Microplastics are found in the air of building spaces made from recycled plastic waste with varying levels every day. The average level of microplasty in the air for 30 days was 30,8 particles/m2/day. Maximum microplastic rate of 63 particles/m2/day, and minimum rate of 18 particles/m2/ day. The average air temperature when sampling is 25,48 ºC, air humidity is 68,37 % and ultraviolet intensity is 860 mwatt/cm2. Conclusions: Microplastic levels in the air of building spaces made from recycled plastic waste that can not be identified can be identified whether they are still within safe limits or not. This is because there is no regulation in Indonesia even in the world that regulates the safe limit of microplastic levels in the environment.

Distribution of microplastics on sandy beaches in western and southern Japan and their fate in the oceans

The Japanese archipelago is surrounded by the Sea of Japan, the Sea of Okhotsk, the Pacific Ocean, and the East China Sea. The oceans are known to be contaminated by waste artifacts (marine litter). To investigate how these artifacts contaminate sandy beaches in Japan and their fate in the oceans, we sampled sand from 19 sandy beaches ranging from the western area of the main island of Japan (Honshu), which faces the Sea of Japan, to the westernmost island in the Japanese archipelago (Yonaguni Island), which faces the East China Sea. Almost all beaches were contaminated by marine litter. The maximum density by number of pieces was 604,600 per m3 in a 2-cm depth of sand on Yonaguni Island. Polystyrene foam was the most common artifact, and plastic fragments were second. The densities of artifacts by number and weight, and the type of artifacts, varied by location. A statistically significant positive relationship between the weights of artifacts and natural objects was observed, suggesting that they experience similar fates in the oceans. The major axis of the polystyrene foam in the Yonaguni area differed significantly from those in the Shimane, Tsushima, and Okinawa areas. The major axis in the Tsushima area significantly differed from those in all other studied areas. This study found the geological difference in the distribution and the major axis of polystyrene foams. These differences may be relevant to environmental physical factors (wind, rain, and waves), chemical alterations by ultraviolet rays, exposed time, the gyre, and local currents.

Adsorption behavior of nano polyethylene for bensulfuron-methyl in an aqueous environment

Agricultural plastic film, which is widely used to maintain heat and moisture during agricultural production, could gradually degrade into micro- and nano-scale polyethylene plastic fragments when not properly treated. The polyethylene plastic fragments, with ideal properties to carry hydrophobic compounds, interact with pesticide molecules, forming co-exposed residues that persist in the environment. In this work, a small and representative nano-polyethylene particle (PE-NPs, 500 nm) were selected as the adsorption carrier, and bensulfuron-methyl, a commonly used herbicide for crops (e.g. rice and wheat) covered under agricultural plastic films, was chosen as the target analyte to investigate their adsorption behavior. The adsorption equilibrium time of bensulfuron-methyl on PE-NPs increases(6–12 h) with the increase of plastic dosage(500 mg/L-2000 mg/L). The adsorption capacity showed an increasing and then decreasing trend as the dosage of plastic increased, with the highest value achieved at around 500 mg/L. The adsorption behavior was influenced by environmental factors, for example, adsorption was significantly inhibited at pH=9.0 or NaCl concentrations above 0.05 mg/g or dissolved organic matter (oxalic acid) concentrations above 10 mg/L. In addition, The adsorption of bensulfuron-methyl aligned relatively close with pseudo-secondary kinetics and the Freundlich model, suggesting that surface adsorption, intraparticle diffusion, and mass transfer might play a role in the process of non-uniform multilayer adsorption. The adsorption thermodynamics experiment indicated that the adsorption process was spontaneous, heat-absorbing, and mainly physisorption.

Alteration and progressive degradation of plastic waste in a polish operational landfill analysed over 60 years

Polyethylene (PE) plastic waste poses an environmental challenge. To explore degradation processes over an extended period, a 60-year study was conducted at an operational landfill in Poland. This landfill, in use since 1960, offers a unique chronological representation of degradation potential due to distinct layering of waste without mixing. Employing analytical techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimeter (DSC), Scanning Electron Microscopy (SEM), and fluorescence microscopy, plastic waste samples were examined over decades. FTIR identified and characterized the samples, revealing traces of degradation. DSC indicated reduced crystallinity, implying diminished chemical stability. SEM showcased plastic fragment liberation, confirming degradation. Fluorescence microscopy and SEM confirmed microorganisms’ involvement, forming colonies around areas of strong delamination. The study provides insights into plastic waste dynamics, emphasizing microorganisms and hydrolytic processes in landfills. This contributes to understanding over 60 years period and underscores the need for waste management to handle plastic pollution effectively.

Microplastics in an advanced wastewater treatment plant: sustained and robust removal rates unfazed by seasonal variations

Microplastics (MP), fragments of plastic generally defined as, less than 5 mm in size, originating from various urban sources, have become a significant environmental concern due to their widespread presence and potential impacts on ecosystems. This study investigates the efficiency of an advanced wastewater treatment plant discharging into the Mediterranean Sea in removing MPs from wastewater. The plant processes wastewater through a series of treatment stages, including screening, desanding, coagulation/flocculation, biological filtration, and sludge incineration. Samples were collected and analysed during three distinct campaigns (dry, rainy, and touristic seasons) to assess the plant’s performance under varying conditions. Using matrix-representative sampling methodologies and Focal Plane Array micro Fourier-Transform Infrared Spectroscopy (FPA-µFT-IR) for MP quantification, the study measured MP concentrations and removal rates. The treatment plant demonstrated high removal rates of microplastics across different periods. Using a mass balance approach, the removal efficiency during the dry sampling period was 99.85%. In the rainy campaign, the efficiency slightly decreased to 99.11% due to increased runoff, while during the touristic period, the efficiency peaked at 99.95%. Polyester was identified as the predominant polymer type. The primary treatment stages, particularly coagulation/flocculation and lamellar settling, are most effective in MP removal. The majority of MPs are retained in the sludge, which is subsequently incinerated, preventing environmental discharge. This research demonstrates that a WWTP employing advanced treatment processes is not a source of MP to the environment but rather a sink. Despite variations in influent MP concentrations across different seasons, the plant consistently maintained high removal rates, effectively mitigating MP pollution. In this study, sludge incineration further ensured that MPs were prevented from entering the environment.

Quantitative analysis of microplastics in beach sand via low-temperature solvent extraction and thermal degradation: Effects of particle size and sample depth

Quantifying trace levels of microplastics in complex environmental media remains a challenge. In this study, an approach combining field collection of samples from different depths, sample size fractionation, and plastic quantification via pyrolysis-gas chromatography–mass spectrometry (Py-GC–MS) was employed to identify and quantify microplastics at two public beaches along the northeast coast of the U.S. (Salisbury beach, MA and Hampton beach, NH). A simple sampling tool was used to collect beach sand from depth intervals of 0–5 cm and 5–10 cm, respectively. The samples were sieved to give three size fractions: coarse (>1.2 mm), intermediate (100 μm–1.2 mm), and fine (1.2 μm–100 μm) particles. Following density separation and wet peroxide oxidation, a low-temperature solvent extraction protocol involving 2-chlorophenol was used to extract polyester (PET), polystyrene (PS), polyamide (PA), and polyvinyl chloride (PVC). The extract was analyzed using Py-GC–MS for the respective polymers, while the solid residue was pyrolyzed separately for polyethylene (PE) and polypropylene (PP). The one-step solvent extraction method significantly simplified the sample matrix and improved the sensitivity of analysis. Among the samples, PET was detected in greater quantities in the fine fraction than in the intermediate size fraction, and PET fine particles were located predominantly in the surface sand. Similar to PET, PS was detected at higher mass concentrations in the fine particles in most samples. These results underscore the importance of beach environment for plastic fragmentation, where a combination of factors including UV irradiation, mechanical abrasion, and water exposure promote plastic breakdown. Surface accumulation of fine plastic particles may also be attributed to transport of microplastics through wind and tides. The proposed sample treatment and analysis methods may allow sensitive and quantitative measurements of size or depth-related distribution patterns of microplastics in complex environmental media.

The first spatio-temporal study of the microplastics and meso–macroplastics transport in the Romanian Danube

BackgroundTransport, accumulation, and degradation of microplastics (MiPs) in the aquatic environment represent a significant concern to the researchers and policy-makers, due to the detrimental impact on biota and human health through food ingestion. Although consistent investigations and research data are available worldwide, comparing the results is still challenging due to the need for more regulations regarding the sampling methods, analysis, and results reporting. The European regulatory efforts include studies on the MiPs transport in the western basin of the Danube River developed with active nets-based multipoint sampling methods from suspended sediments and proposed for standardization. In this context, the present study aimed to address for the first time the transport of MiPs in the Romanian sector of the Danube, starting after entering the country (Moldova Veche) and before the formation of the Danube Delta (Isaccea).ResultsThe multipoint nets sampling procedure facilitated the collection of suspended sediments in the water columns as deep as 0.0–0.6 and 3.0–3.6 m depths and near riverbed sediments (autumn 2022 sampling) during an extensive spatio-temporal study from spring 2022 until spring 2023. The estimate of the maximum annual transport of 46–51 and 93–100 t·y−1 for MiPs and total (micro–meso–macroplastics) MPs at Moldova Veche was based on 135 collected and processed samples using 2021 water flow data. Polyethylene (58–69%) and polypropylene (21–33%) were the main polymer components in the separated fragments, foils, microfibers, and different colors spheroids of MiPs ( < 5 mm), and the foils and fibers of meso–macroplastics (5–100 mm). Advanced investigations highlighted various microstructural degradations of the plastic fragments at the micro- and nanoscale and attached minerals (clays) and heavy metals.ConclusionThis paper presents the first comprehensive data set for microplastic annual transport in the "Low Danube", filling the need for a complete transport assessment in one of the most significant European rivers. 4–5 times lower values were measured before the entrance to the Danube Delta than those from Moldova Veche. The investigations should continue, including flooding events, and the sampling points should be expanded to deeper water column layers during all the campaigns for further validation.Graphical

Recent advancement in microplastic removal process from wastewater - A critical review

Microplastics, small sized plastic particles having size <5 mm are formed through primary process including production of beauty products, microbeads and microfibres as well as secondary process including mechanical weathering, friction, aberration and fragmentation of large plastics. The major sources of microplastics are land-based and ocean-based sources. Microplastic pollution is a serious concern due to the persistent, low biodegradability and bio-accumulative behaviour. Microplastics can bioaccumulate in the food chain and can cause ecological and human health risk. Hence, it is important to remove from the aquatic ecosystems. Microplastics are removed from aquatic systems and wastewater through a series of processes such as physical, chemical and biological treatments. In the present articles, >250 articles are reviewed to collect the information regarding the various physical, chemical and biological methods for the removal of microplastics. Also, the probable control strategies to combat with plastic pollution were assessed. It was concluded that recent water treatment methods are efficient in removing microplastic pollution. The efficiencies to remove microplastic from the water ranged between 74 %-99.2 %, 65 %-99.20 % and 77 %-100 % for physical, chemical and biological treatment methods, respectively. Among the three treatment methods, physical methods especially the filtration of water from biochar is the most efficient way (efficiency up to 100 %) to remove microplastics. It was also concluded that creating public awareness, promoting reusing, recycling and reducing, and application of bioplastics can control the production of microplastics from plastic wastes. This review will be useful to add current knowledge regarding the abatement of microplastic pollution, and finding novel solution to control microplastics. This review will also help the policymakers to implement most effective and cost-efficient method to remove microplastics, and to find out new methods to reduce, reuse and recycle plastic wastes.

Abundance of Marine Macrodebris on the Northern Coast of Jaffna Peninsula, Sri Lanka.

Marine plastic debris has emerged as a pressing concern along the northern coast of Jaffna, Sri Lanka, posing a significant threat to marine resources. A preliminary study was conducted to investigate the abundance and characteristics of marine plastic debris at four major fish landing sites in the northern coast of Jaffna, using the Clean Coast Index (CCI) and Plastic Abundance Index (PAI). The results revealed that the average abundance of marine debris and plastic debris were 1.71 ± 0.42 items/m2 and 1.66 ± 0.57 items/m2, respectively. The most common types of plastic debris represented plastic rope and net pieces (23.2%), followed by unidentified weathered plastic fragments (16.7%), beverage bottles (16.2%), bottle caps and lids (13%), and styrofoam (14.1%). The recognized sources of plastic debris were mainly fishing-based activities, recreation activities, transboundary sources, and unidentified sources. The fish landing sites were classified as exceptionally polluted, with a CCI exceeding 10 and a PAI value exceeding 8. Myliddy had the highest debris density, indicating substantial pollution levels, followed by Point Pedro, Mathagal, and Valveddithurai. These findings underscore the urgency of establishing a comprehensive plastic waste management framework for the northern coast of Jaffna and devising strategies to address buoyant debris within the northern Indian Ocean. Furthermore, this study carries significant implications for the local marine ecosystem, coastal communities, and Sri Lanka's broader environmental policies and practices.

Segmentation of beach plastic fragments’ contours based on self-organizing map and multi-shape descriptors: A rapid indication of fragmentation and wearing types

Environmental plastic fragments have been verified as byproducts of large plastic and its secondary pollutants including micro and nanoplastics. There are few quantitative studies available, but their contours have values for the weathering mechanisms. We used geometric descriptors, fractal dimensions, and Fourier descriptors to characterize field and artificial polyethylene and polypropylene samples as a means of investigating the contour characteristics. It provides a methodological framework for contour classification. Unsupervised classification was performed using self-organizing neural networks with size-invariance parameters. We revealed the isometric phenomenon of plastic fragments during fragmentation, i.e., that the degree of contour rounding and complexity increase and decrease, respectively, with decreasing fragment size. With an average error rate of 8.9 %, we can distinguish artificial samples from field samples. It was also validated by the difference in Carbonyl Index between groups. We propose a two-stage process for plastic fragmentation and give three types of contour features which were key in the description of fragmented contours, i.e., size, complexity, and rounding. Our work will improve the accuracy of characterizations regarding the weathering and fragmentation processes of certain kinds of plastic fragments. The contour parameters also have the potential to be applied in more realistic scenarios and varied polymers.

Atomistic Insights into Impact-Induced Energy Release and Deformation of Core-Shell-Structured Ni/Al Nanoparticle in an Oxygen Environment.

In actual atmospheric environments, Ni/Al composites subjected to high-velocity impact will undergo both intermetallic reaction and oxidative combustion simultaneously, and the coupling of mechanical and multiple chemical processes leads to extremely complex characteristics of energy release. This work employs ReaxFF molecular dynamics simulations to investigate the impact-induced deformation and energy release of a core-shell-structured Ni/Al nanoparticle in an oxygen environment. It was found that Al directly undergoes fragmentation, while Ni experiences plastic deformation, melting, and fragmentation in sequence as the impact velocity increased. This results in the final morphology of the nanoparticles being an ellipsoidal-clad nanoparticle, spherical Ni/Al melt, and debris cloud. Furthermore, these deformation characteristics are strongly related to the material property of the shell, manifested as Ni shell-Al core particle, being more prone to breakage. Interestingly, the dissociation phenomenon of Ni-Al-O clusters during deformation is observed, which is driven by Ni dissociation and Al oxidation. In addition, the energy release is strongly related to the deformation behavior. When the nanoparticle is not completely broken (Ni undergoes plastic deformation and melting), the energy release comes from the oxidative combustion of Al fragments and the intermetallic reaction driven by atomic mixing. When the nanoparticle is completely broken, the energy release mainly comes from the oxidative combustion of the debris cloud. At the same time, the promoting effect of oxygen concentration on the energy release efficiency is examined. These findings can provide atomic insights into the regulation of impact-induced energy release for reactive intermetallic materials.

Enhancing biodegradation efficiency of PLA/PBAT-ST20 bioplastic using thermophilic bacteria co-culture system: New insight from structural characterization, enzyme activity, and metabolic pathways

The rising utilization of PLA/PBAT-ST20 presents potential ecological risks stemming from its casual disposal and incomplete degradation. To solve this problem, this study investigated the degradation capabilities of PLA/PBAT-ST20 by a co-culture system comprising two thermophilic bacteria, Pseudomonas G1 and Kocuria G2, selected and identified from the thermophilic phase of compost. Structural characterization results revealed that the strains colonized the PLA/PBAT-ST20's surface, causing holes and cracks, with an increase in the carbonyl index (CI) and polydispersity index (PDI), indicating oxidative degradation. Enzyme activity results demonstrated that the co-culture system significantly enhanced the secretion and activity of proteases and lipases, promoting the breakdown of ester bonds. LC-QTOF-MS results showed that various intermediate products were obtained after degradation, ultimately participating in the TCA cycle (ko00020), further completely mineralized. Additionally, after 15-day compost, the co-culture system achieved a degradation rate of 72.14 ± 2.1 wt% for PBAT/PLA-ST20 films, with a decrease in the abundance of plastic fragments of all sizes, demonstrating efficient degradation of PLA/PBAT-ST20 films. This study highlights the potential of thermophilic bacteria to address plastic pollution through biodegradation and emphasizes that the co-culture system could serve as an ideal solution for the remediation of PLA/PBAT plastics.

Effects of Microplastics on Animal Health and Nutrition

Macro plastics are defined as plastics that are larger than 20 cm. Plastics that measure between 5-20 cm are referred to as mesoplastics, while those between 1-5 mm are known as large microplastics. Plastics that measure between 1-1000 μm are called small micro plastics, and those that are smaller than 1000 μm are referred to as nano-plastics. Microplastics are particles that result from the degradation of plastic products or are specifically produced in the form of small pieces. They are considered to be less than 5 μm in size. Micro plastics have come to the fore in re-cent years and are pollutants of major concern to the environment. Plastic materials are commonly used on farms, but they can have negative effects on farm animals. Ruminants such as cattle, sheep and goats require cellulolytic micro-organisms for fiber digestion in their diet. The micro biota of the digestive system varies according to dietary habits. The digestive system and other organs can be adversely affected by sudden changes and damage to the micro biota. The ingestion of large plastic materials causes rumen complications such as rumen atony, indigestion and tympani in livestock. Ingested plastic fragments degrade in the digestive tract, increasing the number of small particles likely to be ingested. In a recent study, the presence of low-density micro plastics in sheep feces suggests that animals can ingest micro and macro plastics from their environment and feed. The increase in demand for the consumption of plastics worldwide is increasing the production of plastics. This situation causes the presence of micro plastics to increase rap-idly day by day. Even if the production of plastics decreases, the continuous degradation of plastic waste in the earth will continue the formation of micro plastics and cause environmental pollution. The effects of microplastics in our coun-try should be investigated by conducting detailed studies from the perspective of veterinary medicine.

Sources and distributions of microplastics and the hazards to plants, animals and human health:A review.

The increases in plastic production and inadequate plastic waste management have significantly increased the presence of microplastics (MPs) in the environment. MPs refer to plastic fragments and particles with a size smaller than 5 millimeters. Numerous studies have focused on the impacts of MPs on the environment and living organisms, and explored the potential mechanisms. Humans and other organisms can ingest or carry MPs through various pathways, which have a range of adverse effects on metabolism, functionality, and health. Additionally, due to their larger surface area, MPs could adsorb various pollutants, including heavy metals and persistent organic pollutants, severely affecting the health of animals and humans. Based on research on MPs in recent years, we reviewed the sources and distribution of MPs, examined exposure pathways, toxic effects, and toxicological mechanisms on plants, animals, and human bodies, and provided a prospective outlook on future directions for MP research. This review would be a reference for further assessments of the health risks of MPs.

Occurrence and identification of microplastics retained in corrosion deposits of drinking water transmission pipes

The irregular structure and high porosity of corrosion deposits create suitable conditions for the retention, accumulation and adsorption of microplastics (MPs) and nanoplastics (NPs) transported by distributed water. Due to the low mass and continuous degradation of MPs, under certain conditions (e.g., changes in water composition or hydraulic conditions, network failures), these particles can be re-released into the water, causing secondary contamination. This paper presents preliminary results on the degree of MP contamination of sediments lining the inner surface of metal alloy pipes taken from a municipal drinking water distribution network. The isolated particles were assessed in terms of number, shape, residence time in the network, and origin. Plastic fragments classified as MPs and NPs were found in all analyzed corrosion deposits. Fragments smaller than 50 μm predominated, indicating a high level of plastic fragmentation associated with advanced degradation and prolonged residence in the environment. The predominant plastics identified were polyethylene (PE), polyethylene terephthalate (PET), and polyamides. High-carbon particles, most likely NP particles, whose presence in drinking water may pose a high health risk to consumers due to their potential to migrate into body tissues, were very abundant in the sediments but impossible to count with the techniques used. The results indicate the need to intensify research on the content of MPs and NPs not only in drinking water, but also in the sediments covering the interior of distribution pipes, and to identify factors that may cause their secondary release into bulk water.

Microplastic contamination in the agri-food chain: The case of honeybees and beehive products

Microplastics, MPs, plastic fragments with a dimension lower than 5 mm, and microfibers, MFs, synthetic and natural/artificial fibrous fragments with a diameter lower than 50 μm, are ubiquitous pollutants identified in different environmental compartments. In this work the occurrence of MPs and MFs on honeybees, Apis mellifera, and beehive products was evaluated, using Fourier transform infrared microspectroscopy, confirming that MPs and MFs are widely present as air contaminants in all the apiary's areas (high and low urbanized areas) in Southern Italy.Results indicated that independently from the site, both honeybees and honey samples, are contaminated by MFs with non-natural color. The majority of MFs were of natural origin followed by artificial MFs and synthetic MFs. Moreover, the chemical composition of MFs isolated from honeybees reflect that used in synthetic fabrics, leading to the hypothesis that they are released from textile to air where are captured by bees. Results highlight that MFs represent a class of ubiquitous airborne anthropogenic pollutants. The identification of polytetrafluoroethylene, PTFE, MPs in honeybees confirm the recent findings that PTFE MPs are diffuse soil and air contaminants while the identification of polyethylene, PE, based MPs in honey samples, from low density urban sites, could be correlated to the large use of PE in agriculture. In the honey samples, also polycaprolactone, PCL, MPs were identified, mainly in high density urban sites, confirming that biodegradable materials could be further pollutants in the environments. The results indicate that honeybees are contaminated by MPs and MFs during their flights or picking up from the hive components, flowers, from other nest mates, from the clothes of the beekeeper, among others and some of them could be transferred to honey samples that could be also affected by soil contamination.

Reproduction, growth and oxidative stress in earthworm Eisenia andrei exposed to conventional and biodegradable mulching film microplastics

Plastic contamination in agricultural soils has become increasingly evident. Plastic mulching films are widely used in agricultural practices. However, the increased use of biodegradable plastics has, to some extent, replaced their non-degradable counterparts. The fragmentation of plastics generates microplastics (MPs), posing risk to soil functions and organisms. In this study the effects of low-density polyethylene microplastics (PE-MP) and polybutylene adipate terephthalate biodegradable microplastics (PBAT-BD-MP) originating from mulching films on the earthworm Eisenia andrei were studied. The earthworms were exposed to seven concentrations (0, 0.005, 0.05, 0.1, 0.5, 1, and 5 % w/w) based on environmentally relevant levels and worst-case scenarios on soil contamination. Survival, growth, reproduction, and biomarkers for oxidative stress [superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione S-transferase (GST), glutathione (GSH), and lipid peroxidation (LPO)] were analysed. Additionally, the Integrated Biomarker Response Index (IBR) was calculated to assess the overall oxidative stress status of the earthworms. Results showed that PE-MP exposure slightly decreased the biomass of the earthworms towards higher concentrations, whereas PBAT-BD-MPs induced growth at lower concentrations. MPs did not have a significant effect on Eisenia andrei reproduction; however, a slight negative trend was observed in juvenile production with increasing PE-MP concentrations. Both PE-MP and PBAT-BD-MP affected antioxidant system, PE-MPs with changes in CAT and GR levels and PBAT-BD-MPs inducing effects on SOD and LPO levels. Additionally, both MPs exhibited effects on soil parameters, resulting in increased soil pH and water-holding capacity at 5 % concentration. Changes in soil parameters can further affect soil organisms such as earthworms. This study provides understanding of the ecotoxicological effects of conventional and biodegradable microplastics on the earthworm Eisenia andrei. It also shows that MP particles of both conventional and biodegradable mulching films induce oxidative stress, considered as an early-warning indicator for adverse ecological effects, in environmentally relevant concentrations.