Impact statement
Plastic pollution has become one of the most pressing environmental and public health challenges of the twenty-first century, and its presence in drinking water represents a direct and previously underexplored route of human exposure. While microplastics have been widely documented in oceans, rivers, and bottled water, baseline data on their occurrence in municipal tap water systems across Central and Eastern Europe remain extremely limited. This pilot study addresses that gap by providing the first quantitative and compositional characterization of microplastics in the residential tap water network of Wrocław, Poland. By combining Fenton oxidation, density separation, scanning electron microscopy and Fourier-transform infrared spectroscopy, the work establishes a reproducible analytical framework that other Central European cities can adopt for routine monitoring. The detection of fibers as the dominant morphology and polyethylene and polypropylene as the dominant polymers indicates that conventional drinking water treatment, even where water quality is generally regarded as high, does not fully retain small polymeric particles. These findings have direct implications for water-utility operators, public health authorities and policymakers tasked with updating treatment standards, evaluating exposure risks and planning evidence-based upgrades to filtration infrastructure. The baseline reported here is intended to support comparable measurements across Europe and to inform future regulatory frameworks for microplastic contamination in potable water.
Introduction
Polymer particles with a size range from 1 μm to 5 mm in diameter are considered microplastics (MPs/MP). Most of them are generated due to the natural breakdown of particles in the environment. Studies showed that MPs can be found in drinking water (Cao et al., Reference Cao, Vo, Pham, Nguyen, Nguyen, le, Mukhtar, Nguyen, Visvanathan and Bui2024). MPs can interact with biological systems and pose toxic effects on human health, as they can carry harmful chemicals and persistent organic pollutants (POPs) (Boctor et al., Reference Boctor, Hoyle, Farag, Ebaid, Walsh, Whiteley and Murphy2025). Another investigation shows that MPs can make their way through municipal water treatment systems, leading to the possibility of MPs in tap water (Boctor et al., Reference Boctor, Hoyle, Farag, Ebaid, Walsh, Whiteley and Murphy2025).
People worldwide consume 2–3 L of water every day (Zhang et al., Reference Zhang, Xu, Li, Chen, Ma, Zeng and Shi2020). MP contamination in tap water has the potential to cause long-lasting impacts (Iroegbu et al., Reference Iroegbu, Sadiku, Ray and Hamam2020). Traditional water treatment plants are unable to capture small particles, which allows MPs to enter the tap water system (Lam et al., Reference Lam, Ho, Ma and Fok2020; Rasheed and Tshomo, Reference Rasheed and Tshomo2024). Considering exposure hazards to people who consume tap water daily, it is important to estimate the contamination level of MPs in it. With variations of polymer type based on geographical location and morphology, the microplastic contamination problem is reported globally (Kirstein et al., Reference Kirstein, Gomiero and Vollertsen2021).
In terms of morphology, the most common forms are fiber and fragments, as found in many studies (Johnson et al., Reference Johnson, Ball, Cross, Horton, Jürgens, Read, Vollertsen and Svendsen2020). They can come up from industrial operations, domestic sources and transportation-related activities (Danopoulos et al., Reference Danopoulos, Twiddy and Rotchell2020). By applying comprehensive scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to identify the abundance, type and morphology of MP in tap water of Wroclaw, this research study will extend previous studies. This study aims to close the necessary gap in global efforts to get insights into MP contamination in drinking water by evaluating the abundance, their shape and chemical makeup in the tap water of Wroclaw.
Although MPs have been widely investigated in tap water worldwide, reported concentrations vary considerably due to differences in sampling methods, pore size and analytical detection limits. Moreover, limited information exists for municipal drinking water in Central and Eastern Europe, where treatment plants differ in filtration design and river water sourcing. In Poland, Wrocław relies on surface water sourced from the Nysa Klodzka and Olawa Rivers, treated at the Mokry Dwor and Na Grobli facilities, yet no baseline assessment of MP has been reported for its potable network. This study provides the first characterization of MP in the tap water of Wrocław. We quantified particle abundance, examined morphological features using SEM and confirmed polymer composition using FTIR.
In this research investigation of MP pollution within the Wroclaw tap water system, the study aims to (1) quantify the abundance, (2) analyze the morphology and (3) identify the chemical composition of the MPs. This research contributes to the growing body of knowledge on environmental contamination and public health by establishing the baseline prevalence of various types of MPs in tap water. These results establish a baseline for MP contamination in Polish drinking water and offer insights into potential treatment limitations in Central Europe.
Materials and methods
Sampling sites
The designated study location was Wroclaw, which is a vibrant city with an area of 292.8 km2, a latitude of 51.1093°N and a longitude of 17.0386°E, where the municipality supplies water to homes (Figure 1). According to world population review report, Wroclaw population is approximately 642,228 (2025). Sampling sites were carefully chosen, which include five residential areas, representing urban zones. The five residential sampling locations were selected to provide an exploratory spatial representation of tap water conditions in Wrocław. Given the limited number of independent composite samples, the sampling design was not intended to provide a statistically representative assessment of the entire municipal water network. Methodological framework for sample collection and analysis is shown in Figure 2.
Study area and sampling locations in Wrocław, Poland. (A) Location of Wrocław within Europe, with a regional inset map. (B) Administrative boundary of the study area (red outline) showing major rivers and urbanized zones, with sampling sites (S1–S5) marked. (C) High-resolution aerial view of the sampling locations within the residential area. The geographical coordinates of Wrocław are 51.1093°N and 17.0386°E.
Figure 1. Long description
Panel A locates Wrocław in Poland within Europe. Panel B shows the study-area boundary, rivers, urban areas and sites S1–S5, clustered in the southeastern part of the mapped area. Panel C shows the five sites on separate residential buildings in an aerial view. Scale bars are 500 km, 10 km and 50 m, respectively.
Methodological framework of the study.
Figure 2. Long description
The framework has three branches. Literature review covers assessment techniques, laboratory protocols, glassware rather than plastic, sampling methods, human exposure, ecosystem contamination and bioaccumulation. Sampling strategy covers residential site selection, avoidance of construction zones, altitude and accessibility, tap flushing, sampling duration and avoiding plastic contact. Preparation includes Fenton oxidation, zinc chloride separation, vacuum filtration and procedural blanks. Analytical techniques include vacuum-assisted filtration through 0.22 μm membranes, equipment rinsing and sterilization, SEM surface morphology and FTIR polymer identification by reference-database comparison.
Sample collection and preparation
Each water sample was collected directly from housing taps and retained in a precleaned 1-L water bottle (Figure 3). At each sampling site (Buildings 1–5), three tap water subsamples (R1–R3) with a volume of 333 ml were collected following ISO 5667-3:2018 and established microplastic sampling guidelines. Each subsample was gently inverted to ensure homogeneity prior to compositing. The tap was flushed for 3 minutes at a controlled flow rate of 6–7 L min−1, and water was collected in amber-glass bottles with caps.
Schematic diagram of pretreatment, isolation and identification of MP in tap water.
Figure 3. Long description
The process moves from sample collection to MP isolation and identification. Three 333 mL portions are combined into a 1 L sample. Samples undergo oxidative digestion by the Fenton reaction, density separation with zinc chloride labelled 2.907 g/cm³, vacuum filtration, and SEM and FTIR analysis. Contamination controls shown beneath the workflow are glassware, filtered reagents, a closed hood and personal protective equipment.
A 1-L composite sample per building (S1–S5) was prepared by transferring 333 ml from each subsample into a pre-cleaned glass bottle using graduated cylinders. All transfers were performed inside a portable laminar-flow hood using glassware rinsed with filtered deionized water. The process was done in the Mineral Processing Lab, Unit W6 of Wroclaw University of Science and Technology (WUST), at ambient temperature. Samples were processed immediately upon arrival.
Analysis techniques
To eliminate organic pollutants, the Fenton reaction was conducted (Chen et al., Reference Chen, Fu, Yang and Wang2020), which uses hydrogen peroxide (H2O2) and iron salts for the formation of hydroxyl radicals (.OH) that later oxidize organic molecules. Until the vigorous effervescence at 75°C, the mixture was kept on a hot plate (Figure 3). After boiling of samples and observing clear visible bubbling, the samples were removed from the hot plate until all the bubbles disappeared. While tap water usually contain very minimal amount of organic contamination, the Fenton reaction and density separation were performed as a precautionary measure to eliminate any minimal inorganic and organic residue that could interfere with morphological identification. The overall reaction proceeds as:
where, OH represents hydroxyl radicals.
Because increased temperature during oxidative digestion may induce polymer-dependent changes in particle surface morphology, this treatment condition is recognized as a methodological limitation. Consequently, SEM-derived morphology and size characteristics are interpreted cautiously.
The ZnCl2 solution used for density separation had a density of approximately 2.907 g cm3 at room temperature. Following the 24 hours settling period, the sample was subjected to vacuum filtration.
Vacuum filtration process
After organic contaminants were eradicated, the samples were vacuum filtered for the separation of MPs from other possible contaminations. Operating at a minor pressure of 1/10 atmosphere (100 mbar or 76 Torr), the vacuum filter device established a constant flow to maximize particle retention and minimize clogging. Strained samples were then dried out in a pollution-free Petri dish to prepare for further microscopic and spectroscopic analyses. A microporous membrane made up of hydrophilic mixed cellulose esters (MCE), with reference no. G1S439921 was used for the samples. The membrane filter pore size was 0.45 μm, which proficiently gathered microplastic particles in the range of micrometer size and was used for the filtering process.
Scanning electron microscope (SEM)
Each sample filter was prepared for morphological analysis using a VEGA 3 SEM (TESCAN, Czech Republic) (Figure 4). The filters were mounted on SEM stubs using conductive adhesive tape and subsequently sputter-coated using a Cressington 108 sputter coater (Cressington Scientific Instruments, UK) equipped with a silver target. The sputter-coating process was performed for 60 seconds at a chamber and a sputtering current of 40 mA. SEM observations were performed at an accelerating voltage of 5 kV. Images were acquired at different magnifications to evaluate particle morphology, dimensions and surface characteristics. The magnification and corresponding scale bar were recorded in the footer of each SEM micrograph. Particular attention was given to the identification and morphological classification of fiber- and fragment-like particles. SEM was used for morphological characterization and particle-size assessment, whereas polymer identification was performed separately using FTIR spectroscopy, as described in section “Fourier transform infrared spectroscopy (FTIR).”
Schematic diagram of the working mechanism of a scanning electron microscope (SEM).
Figure 4. Long description
A thermionic cathode in the electron gun emits primary electrons toward an anode. An electromagnetic lens focuses the beam, and deflection coils controlled by a raster scan generator scan it over the sample. The sample rests on a stage in a specimen chamber connected to a vacuum pump. A secondary-electron detector collects emitted electrons; an X-ray detector is also shown. Detector signals pass to a computer that displays the magnified surface image.
Particle abundance was quantified as the total number of microplastic particles detected per sample. Because only five independent composite samples were available, statistical analysis was restricted to descriptive summaries. Particle abundance was reported individually for each sample together with the median, interquartile range (IQR), minimum and maximum. Particle-size distributions were visualized using boxplots and empirical cumulative distribution functions (ECDFs). No inferential comparison among sampling locations was performed.
Fourier transform infrared spectroscopy (FTIR)
Microplastic particles with a specific polymer type were identified using FTIR, BRUKER Alpha II (Bruker, Billerica, MA, USA) with an ATR module. Spectra were taken by means of Attenuated Total Reflectance (ATR) mode, spanning a wavenumber range of 500–4000 cm−1 with 4 cm−1 resolution. The spectra of each particle were matched with a reference database to find distinguishing peaks associated with common polymer types, including polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). To determine the possible cause of MP pollution in the tap water, it was necessary to get a clear understanding of the polymer chemical composition found in the samples, which could be identified using FTIR spectroscopy. Polymer identifications were carried out by comparing sample spectra to the BRUKER OPUS reference library using ≥70% match score criteria.
Quality assurance and quality control
To reduce sample contamination during the collection and analysis stage, all procedures were performed in a closed fume hood. Laboratory slabs were cleaned with ethanol, and all the equipment was washed before every analysis session. During the procedure, plastic-free equipment’s were used to prevent external contamination with plastic particles from handling. Gloves were avoided during sample preparation to minimize the risk of glove microfibers getting into the samples. These safeguards were adopted to guarantee that the particles found during analysis reveal actual contamination in samples, and not the byproducts of laboratory operations. No independent airborne fallout controls were deployed outside the enclosed sample-handling procedures. Although airborne exposure was minimized, residual airborne contamination, particularly from fibers, cannot be completely excluded. No polymer spike-and-recovery experiment was performed; consequently, extraction recovery efficiency could not be quantified, and the reported particle concentrations were not recovery-corrected. A MCE membrane was used as the filtration substrate in the present investigation. Future investigations should preferentially employ an appropriate non-plastic or inorganic filtration substrate compatible with the targeted particle-size range and subsequent analytical technique.
Results
Microplastic abundance
In Wroclaw residential tap water, the observed contamination of MPs was 23–45 microplastic particles per liter (MP/L) across five locations. The median concentration was 37 MPs/L (IQR: 35–41 MP/L) (Figure 5; Table 1). These values represent spatial variability among household taps. Observed differences among the samples may be influenced by the local water supply network and household pumping. Particle abundance varied among the five tap water samples, with the highest counts observed in samples S4 and S5. Microplastics abundance per sample are shown in Figure 5, but harmonized size-fraction reporting would be useful in future larger studies.
(A) and (B) showing microplastic abundance (MP/L) measured in individual residential tap water samples collected at five locations in Wroclaw.
Figure 5. Long description
Panel A is a bar chart with approximate abundances of 37, 23, 36, 49 and 47 particles/L for S1–S5. Small capped lines appear at the tops of the bars. Panel B is a point plot with approximate abundances of 37, 23, 36, 45 and 40 MPs/L for S1–S5. Both panels show S2 as the lowest and S4 as the highest. Values are approximate readings from the plotted marks; S4 and S5 differ between panels.
Descriptive statistics of microplastic abundance (MP/L) across residential tap water samples
Table 1. Long description
The table consists of two rows and six columns.
Column 1, Statistics: Values in M P / L.
Column 2, Min: 23.
Column 3, Max: 45.
Column 4, Median: 37.
Column 5, I Q R: 35 to 41.
Column 6, Range: 23 to 45.
The values shown above represent the microplastic abundance across the analyzed tap water samples (n = 5). Given the limited number of samples and the exploratory nature of the study, results should be interpreted as indicative baseline values rather than large-scale estimations.
The particle size of MPs in tap water varied considerably across the sampling locations, with median sizes generally ranging between approximately 20 and 60 μm (Figure 6). Particle-size distributions differed descriptively among the five samples, as illustrated by the boxplots and ECDFs. Given the exploratory sampling design, these differences were not subjected to inferential between-site testing. All samples contained particles below 50 μm, and also exhibited broader distribution extending above 100 μm, indicating the presence of fine particles. The IQRs differed among the samples, suggesting spatial variability in fragmentation level and particle morphology. ECDFs of particle size distribution for samples S1–S5 were plotted on a logarithmic diameter scale.
(A) Box plot indicating the particle size (μm) for all samples. (B) Empirical CDF of particle size distribution.
Figure 6. Long description
Panel A shows size in micrometres using boxes for the 25th–75th percentiles, red median lines, open-circle means and whiskers labelled as the range within 1.5 interquartile ranges. Approximate medians for S1–S5 are 22, 30, 57, 43 and 62 µm. S3 has the highest upper whisker, near 160 µm. Panel B plots cumulative probability from 0 to 1 against particle diameter on a logarithmic micrometre scale. S1 and S2 generally accumulate at smaller diameters, while S5 is shifted toward larger diameters.
Number-based distribution indicate a predominance of smaller particles, whereas surface area and volume distribution progressively shift toward larger particle sizes, reflecting the increasing contribution of coarse particles to total surface area and volume (Figure 7).
(A) Differential particle size distributions expressed as number (%), (B) volume (%) and (C) surface area (%) for samples S1–S5 plotted on a logarithmic diameter scale.
Figure 7. Long description
Three line plots use particle diameter in micrometres on a logarithmic horizontal axis, with separate curves for S1–S5. Panel A shows differential number percentage, with contributions spread across the diameter range and a prominent S5 peak above 100 µm. Panel B is labelled differential volume percentage; most contributions occur at diameters of roughly 50–160 µm, with S3 reaching about 35% at the largest plotted diameter. Panel C is labelled differential surface-area percentage and also concentrates contributions at larger diameters, with S3 reaching about 27% at the largest diameter. The visible panel labels place volume in B and surface area in C.
Across the five tap water samples, particle size distribution exhibited consistent number–surface–volume scaling behavior. Number-based distribution was dominated by smaller particles, whereas surface area and volume distribution progressively shifted toward larger particle sizes. Despite their low numerical abundance, coarse particles (>~80 μm) contributed disproportionately to surface area and volume, consistent with established particle scaling relationship.
Microplastic morphology
SEM revealed that fibers were the predominant microplastic form in tap water, displaying elongated thread-like morphology with irregular contours and variable surface textures (Figure 8). Fiber-like MPs, which often appear as thin and long strands, made up a sizeable constituent of the entire particle count. The fiber type particle dominance was also found in earlier studies. Due to flexibility and durability, fibers can move to metropolitan water facilities. Particle morphology shows that fibers were more dominated as compared to fragments. Particle color was not systematically documented prior to SEM preparation. Because SEM imaging produces grayscale images and the particles were subsequently metal-coated, reliable retrospective color classification was not possible. Therefore, quantitative color distribution is not reported in the present study.
Scanning electron microscopy imaging of the identified MPs in different samples. SEM analyses were conducted in the W7 Unit, Department of Environmental Engineering (WUST).
Figure 8. Long description
A large grayscale SEM image shows scattered dark elongated particles and smaller objects on a fibrous filter surface. Three connecting lines link selected regions to enlarged views: an upper central inset, a right inset and a lower central inset. The enlarged views show straight, curved and sharply bent fiber-like objects, with smaller irregular particles nearby. The overview is labeled 20× magnification, 5.0 kV and a 2 mm scale bar. No individual sample identifiers or polymer identities are marked.
Microplastic chemical composition
In terms of chemical composition, the two most predominant types of polymers found in the tap water of Wroclaw were PE and PP, followed by PET and polyvinyl chloride (PVC) identified with FTIR (Figure 9).
Fourier-transform infrared (FTIR) spectra of identified microplastics: (A) polyethylene (PE), (B) polypropylene (PP), (C) polyvinyl chloride (PVC) and (D) polyethylene terephthalate (PET). Characteristic absorption bands are highlighted, including C–H stretching and deformation vibrations (e.g., ~730–1471 cm−1 for PE, ~1375 cm−1 for PP, ~1430 cm−1 for PVC and ~1370 cm−1 for PET), confirming polymer identification. Spectra were acquired over the range of 500–4000 cm−1.
Figure 9. Long description
The four panels plot absorbance, labelled as percent, against wavenumber in cm−1. Panel A is polyethylene (PE), with annotations at 730 and 1471 cm−1. Panel B is polypropylene (PP), with a callout spanning 1375–1455 cm−1 and a peak label at 1455 cm−1. Panel C is polyvinyl chloride (PVC), with an annotation at 1430 cm−1. Panel D is polyethylene terephthalate (PET), with a callout spanning 1370–1410 cm−1 and a peak label at 1370 cm−1. The callouts identify C–H deformation. The traces show several peaks mainly below about 1800 cm−1 and comparatively low absorbance at higher wavenumbers.
By FTIR spectra, polymer types were confirmed, which showed a clear peak for PE and PP (Figure 10). These polymer types were found to be consistent in different samples, suggesting that these are the main pollutants in the water samples. Moreover, the presence of PE and PP in this research is consistent with previous studies. Most of the particles found in this research were micrometers in size, which indicates that these technologies might be effective at removing organic pollution and particles of macrometer size, but not at removing small particles. This suggests the necessity of upgrading the water treatment facilities for the timely capture of micro particles.
Polymer composition among all the samples.
Figure 10. Long description
Polymer composition: polyethylene 44.7%, polypropylene 31.5%, polyethylene terephthalate 14.2% and polyvinyl chloride 9.6%.
Among all the polymer type detected, PE accounted for 44.7%, PP for 31.5%, PET for 14.2% and PVC for 9.6% of the total microplastic particles identified across all sampling sites.
Discussion
Across various studies on MPs, differences in geographical features, infrastructure, environment, population and treatment methods could be considered as influencing factors of heterogeneity in MP concentrations (Paul et al., Reference Paul, Stock, Cara-Carmona, Lisicki, Shopova, Fessard, Braeuning, Sieg and Böhmert2020). The highest MP abundance found, for example, may be explained by a study conducted in heavily urbanized areas with intense industrial activity (Chen et al., Reference Chen, Fu, Yang and Wang2020). In Danish tap water, out of 124 particles, only 3% were identified as MPs with FTIR analysis, and the most common types of identified particles were PET, PP, PS and ABS (Novotna et al., Reference Novotna, Cermakova, Pivokonska, Cajthaml and Pivokonsky2019). Another study in Greater Paris also indicates a substantial number of MPs in water (Lam et al., Reference Lam, Ho, Ma and Fok2020). Considering the possible health effects, our study confirms the presence of microplastic pollution in Wroclaw. A high amount of MPs identified in studies, especially those smaller than 1.1 μm, raises the possibility that current water treatment techniques are not sufficient to capture tiny particles coming from industries or households (Feld et al., Reference Feld, Da Silva, Murphy, Hartmann and Strand2021).
While comparing this study results with earlier research, the differences in the reported concentrations can be traced back to the varying analytical resolutions (like the FTIR settings, filtration pore size, extraction chemistry) and particle size limit. Studies that only detected ≥100–300 μm particles often did not report the tiny fractions that were detected here (<1.1 μm). The particles detected at household taps may potentially originate from several stages of the drinking-water pathway, including source water, incomplete removal during treatment, mobilization within the municipal distribution network and building plumbing or household fixtures. However, the present endpoint sampling design cannot distinguish among these potential pathways. Polymer identity alone is insufficient for source attribution, and investigation of raw water, post-treatment water, distribution-system locations and site-specific plumbing materials would be required to identify individual sources.
The results of this investigation show that PE and PP support the results of many previous studies. PE and PP extensively originate in aquatic environments because of their widespread usage in packaging and industries (Dris et al., Reference Dris, Gasperi, Rocher, Saad, Renault and Tassin2015). PE and PP were also found in high numbers, demonstrating their rapid spread in the water system (Chu et al., Reference Chu, Zheng, Li, Cai, Peng, Zhao and Tian2022). The occurrence of these polymers at household taps demonstrates their presence at the point of consumption but does not by itself establish the removal efficiency of the municipal treatment facilities (Acarer, Reference Acarer2023). Moreover, evidence that the same polymer type is found in different geographical locations indicates that this is now a local problem that represents a global trend of plastic pollution. On the other hand, polymer types that were less commonly discovered in our study, including polystyrene (PS) and PET, were found in other research studies (Mason et al., Reference Mason, Welch and Neratko2018). SEM permitted visualization of small particle-like features; however, the lower SEM observation range should not be interpreted as equivalent to the ATR-FTIR polymer-identification limit. Only particles producing acceptable ATR-FTIR spectra were considered chemically confirmed polymers.
The present study detected MPs in all residential tap water samples. This evidence is directly relevant to the revised EU Drinking Water Directive 2020/2184, which recognizes MPs as an emerging concern and requires the European Commission to develop a methodology for measuring MPs in water intended for human consumption. Such a methodology was subsequently published through the Commission’s delegated act on microplastic measurement in drinking water. Therefore, the Wrocław baseline can support Poland’s future alignment with EU-level monitoring by providing local reference data before routine MP surveillance becomes more standardized. Although the study is based on a limited number of tap water samples and does not include temporal replications, the results should be interpreted as indicative rather than statistically representative of long-term conditions. Despite these limitations, this study provides the first baseline evidence of MPs occurrence and polymer composition in municipal tap water from Wroclaw, offering valuable reference data and methodological groundwork for future investigations employing large sample sizes and longitudinal designs.
Conclusions
This study provides the first pilot quantitative and compositional assessment of MPs in residential tap water in Wrocław, Poland. The application of validated laboratory preparation procedures (Fenton oxidation, ZnCl₂ density separation and vacuum filtration), combined with SEM-based morphological analysis and FTIR polymer identification, enabled reliable characterization of particles present in the municipal water supply. MPs were detected at concentrations ranging from 23 to 45 particles L−1, with fibers as the predominant morphology. PE and PP were the most frequently observed polymers, indicating a strong contribution from domestic and packaging-related sources typical of surface-water-derived distribution systems.
These results establish a baseline assessment for microplastic contamination in Polish drinking water and highlight the importance of incorporating particle-level monitoring into routine water quality assessment. Although the concentrations observed fall within the range reported for other global municipal supplies, the predominance of fiber-type plastics and the persistence of small particles underscore the need to investigate removal efficiency within the existing treatment infrastructure. Because only five independent composite samples were analyzed and temporal replication was not performed, the results should be interpreted as a pilot rather than as a statistically representative assessment of the Wrocław municipal water network.
Future work should prioritize size-specific detection limits, and assessment of treatment performance across different filtration technologies in Central Europe. Establishing comparable protocols will be essential for advancing exposure evaluation and informing evidence-based improvements in water management strategies.
Abbreviation
- ABS
-
Acrylonitrile Butadiene Styrene
- FTIR
-
Fourier transform infrared spectroscopy
- MPs
-
Microplastics
- PE
-
Polyethylene
- PET
-
Polyethylene terephthalate
- PP
-
Polypropylene
- PVC
-
Polyvinyl chloride
- SEM
-
Scanning electron microscopy
Open peer review
To view the open peer review materials for this article, please visit http://doi.org/10.1017/plc.2026.10070.
Acknowledgements
The authors gratefully acknowledge Prof. Stanisław Frąckowiak, Department of Environmental Engineering, for supporting the use of the SEM facilities. The authors also thank the Mineral Processing Lab of the Department of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology, for providing access to the laboratory facilities.
Author contribution
Conceptualization: Z.R., K.B.; Data curation: Z.R., K.S.; Formal analysis: Z.R.; Investigation: Z.R., K.S.; Methodology: Z.R., K.B.; Software: Z.R.; Validation: Z.R.; Visualization: Z.R., K.S., M.R.; Writing – original draft: Z.R.
Competing interests
The authors declare no conflicts of interest
Data availability statement
All data that support the findings of this study are available.
Funding statement
This research study did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.
Open access
Comments
Zulakha Rasheed
Faculty of Geoengineering, Mining and Geology
Wrocław University of Science and Technology
Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Email: zulakha.rasheed@pwr.edu.pl
7 May 2026
Professor Steve Fletcher
Editor-in-Chief, Cambridge Prisms: Plastics
University of Portsmouth, United Kingdom
Dear Professor Fletcher,
Re: Submission of research article — “Microplastics in Municipal Tap Water of Wrocław: Baseline Occurrence, Morphology, and Polymer Type”
On behalf of my co-authors, I am submitting the enclosed manuscript, “Microplastics in Municipal Tap Water of Wrocław: Baseline Occurrence, Morphology, and Polymer Type,” for consideration as a Research article in Cambridge Prisms: Plastics.
This study provides the first quantitative and compositional baseline of microplastic (MP) contamination in the residential tap-water network of Wrocław, Poland, and to the best of our knowledge it is one of the very few such datasets reported for Central and Eastern Europe. Composite samples from five residential buildings were processed using Fenton oxidation and ZnCl2 density separation, then characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy. We detected 23–45 MP L–1, with fibers as the dominant morphology and polyethylene and polypropylene as the most abundant polymers. The findings indicate that small polymeric particles persist through conventional surface-water treatment and provide a methodological and numerical reference for future monitoring across Central Europe.
We believe this work fits the scope of Cambridge Prisms: Plastics particularly well, given the journal’s interdisciplinary remit linking plastics, environmental quality, and human health. We had the opportunity to discuss the journal directly with Ms Laetitia Beck from the Cambridge Prisms: Plastics team at the EGU General Assembly 2026 in Vienna, where she kindly explained the journal’s aims, article types, and editorial process and warmly encouraged us to submit our work. That conversation was a key reason we have chosen Cambridge Prisms: Plastics as the venue for this study, and we are grateful for her time and guidance.
We confirm that the manuscript is original, has not been published elsewhere, and is not under consideration by any other journal. All listed authors have read and approved the submitted version, agree to be accountable for the work, and declare no conflicts of interest. The research did not receive any specific grant from public, commercial, or not-for-profit funding agencies.
Request for Article Processing Charge (APC) waiver. Because this research was carried out without dedicated external funding and the corresponding author has no institutional or grant-based budget available to cover open-access publication fees, we respectfully request consideration for a full APC waiver under the journal’s open-access waiver policy. We would be very grateful for the editorial office’s support in this regard, and we are happy to provide any further information needed to process the request.
Suggested article type: Research article. The manuscript is approximately 4,250 words and has been prepared in accordance with the journal’s Preparing your materials guidelines, including continuous line numbering, the Cambridge A reference style, an Impact Statement, and a structured abstract.
We hope the editorial board will find our study suitable for Cambridge Prisms: Plastics, and we look forward to the reviewers' feedback. Please do not hesitate to contact me at the address above if any further information or clarification is needed.
Yours sincerely,
Zulakha Rasheed
Corresponding author
on behalf of all co-authors