Characterization of micro- and nanoplastics in human placental tissue by pyrolysis gas chromatographic ion mobility mass spectrometry

Micro- and nanoplastics (MNPs) are pervasive in the environment and are increasingly being detected in human tissues, including placenta, yet their effects on pregnancy outcome remain poorly understood. This study utilized pyrolysis gas chromatography x cyclic ion mobility mass spectrometry (Py-GCxcIMS) to overcome lipid interference and improve quantification of MNPs in human placentas from forty-six participants. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) were targeted for analysis. MNPs were detected in 26% of placental tissue samples (24/92) and in 41% of participants (19/46), with total polymer concentrations ranging from 0.1 to 12.3 μg/g (mean total of 0.5 μg/g). The variability in microplastic concentrations across the different placental regions highlights the organ’s heterogeneous nature. Polypropylene was the most frequently detected, while polystyrene showed the highest mean concentration. Although no direct link to birth outcomes was found, the exploratory analysis suggested sex-specific association in complicated pregnancies (p = 0.071 for males) underscores the need for expanded cohort studies. These results provide evidence of MNP presence in human placental tissue, emphasizing the importance of larger human cohort studies and robust analytical methods to better understand the potential impact MNPs have on pregnancy and fetal health.

Plastics are ubiquitous in modern society and are key ingredients of many of the products used daily. Only a small percentage of plastics are recycled worldwide (Chamas et al., 2020), and their degradation to smaller micro plastics (MPs, diameter < 5 mm) and nano plastics (NPs, diameter < 1 μm) (Hartmann et al., 2019) increases their potential to pollute the environment and enter the human body through inhalation, (Hashemihedeshi et al., 2024) ingestion of contaminated food, (Milne et al., 2024; Udovicki et al., 2022) and drinking water (Gambino et al., 2022). There are also concerns that micro-/nanoplastics (MNPs) can leach additive chemicals that are persistent, mobile, and toxic (Fries et al., 2022). Although plastic pollution in the marine environment have been studied for decades, (Thompson et al., 2004) human exposure to MNPs and the associated health impacts are understudied.

MNPs have been identified in human lungs, (Pauly et al., 1998; Amato-Lourenço et al., 2021; Jenner et al., 2022) liver, (Horvatits et al., 2022) testes, (Hu et al., 2024; Zhao et al., 2023) and blood, (Leslie et al., 2022; Brits et al., 2024; Bissonnette et al., 2025) suggesting systemic circulation with potential placental transfer. MNPs in human placenta were first reported by Ragusa et al. (2021) and since then fourteen studies (Supplementary Table S1) (Braun et al., 2021; Ragusa et al., 2022; Amereh et al., 2022; Zhu et al., 2023; Liu et al., 2023; Weingrill et al., 2023; Halfar et al., 2023; Zurub et al., 2024a; Garcia M. A. et al., 2024; Yun et al., 2024; Sun et al., 2024; Zhu et al., 2024; Oliveira et al., 2025; Zhang et al., 2025) have reported their presence, with significant differences in polymer type, size, and concentration. Polyethylene (PE) (Amereh et al., 2022; Zurub et al., 2024a; Garcia M. A. et al., 2024; Zhu et al., 2024) and polypropylene (PP) (Ragusa et al., 2021; Ragusa et al., 2022; Zhang et al., 2025) are the most frequently detected polymers. A critical question raised is whether MNPs are associated with pregnancy complications and placental dysfunction (Sripada et al., 2022). This has important implications for fetal development and long-term offspring health, although current evidence remains insufficient and inconsistent. Elevated MP counts have been reported in pregnancies complicated by intrauterine growth restriction (IUGR) (Amereh et al., 2022), and MPs have also been detected in preterm pregnancies (Halfar et al., 2023; Zhu et al., 2024). Using a large cohort of healthy pregnancies, MP detection was negatively associated with placental telomere length, suggesting accelerated placental aging (Zhang et al., 2025). However, comparisons of MNP concentrations between complicated and healthy control pregnancies have not been performed.

Studies of MNPs in placenta have mostly employed spectroscopic techniques such as µ-Raman and µ-Fourier transform infrared spectroscopy, which determine MNP size and morphology but are often limited to particles >1 µ m, limiting the detection of nanoscale particles (Ansari et al., 2025). This has driven the development of pyrolysis gas chromatographic mass spectrometry (Py-GC/MS) methods for mass-based quantification of MNPs, (Leslie et al., 2022; Brits et al., 2024; Bissonnette et al., 2025) which has recently been applied to human placenta (Garcia M. A. et al., 2024). However, Py-GC/MS approaches also face significant challenges in differentiating genuine polymer signal from molecules such as lipids in biological matrices (Tan et al., 2026; Rauert et al., 2022). Building on this, we developed a pyrolysis gas chromatography x cyclic ion mobility mass spectrometry (Py-GCxcIMS) method that can quantify MNPs and reduce false positive detection resulting from biological interferences (Bissonnette et al., 2025). The addition of ion mobility provides collision cross section (CCS) values, which reflects the area where collisions between an ion and a neutral gas molecule can occur (Giles et al., 2019). In the present study, we apply this novel technique to characterize polystyrene (PS), PE and PP in placentas from a cohort of 46 pregnant people in Newfoundland and Labrador, Canada. Our Py-GCxcIMS approach increases mobility dimensions enhancing separation by shape and size, therefore increasing detection confidence. Our goal was to report on the presence of MNPs in human placenta from a Canadian cohort and assess potential impacts on pregnancy and fetal health.

Patient cohort

Ethics approval was obtained from the Health Research Ethics Board of Newfoundland and Labrador (REB 2021.015). Forty-six pregnant individuals were recruited from Eastern Health (St John’s, Newfoundland, Canada) from March to July 2024. Patients meeting inclusion criteria (maternal age between 18–45 years and no maternal medical co-morbidities) signed informed written consent. Birth outcome data was obtained from the participants’ medical health records. The participant data was pseudo-anonymized by assigning a one or two-letter alphabetical code at the time of sample collection. The file linking the study code to the participant was stored separately in a secure, locked location and was only available to authorized research team members to check participant health records.

Sample collection

A plastic-free protocol was used to minimize contamination of the samples. After delivery, placentas were transferred directly into a sterile stainless-steel dish (6.25 inch diameter) into the collection room, weighed, and two full depth 10 mm biopsy punch (sterile, stainless steel) samples were collected from mid-placental macroscopically normal areas, avoiding the cord insertion. Samples were stored at −80 °C in 20 mL glass scintillation vials with silver foil liners (ESBE Scientific, ESB-201050). Placental dimensions, umbilical cord characteristics, membrane insertion, and lesions were recorded. Procedural blanks (n = 5) were obtained during placental sampling in the collection room using a sterile stainless-steel dish (6.25 inch diameter), identical to that which was used for sampling. Dust particulate deposited to the dish during sample collection was subsequently rinsed with milli-Q water and transferred into glass scintillation vials. After blank correction, all the procedure blanks had non-detectable levels of MNPs (see Supplementary Table S2).

Sample preparation

The placental tissue samples were removed from the freezer to thaw for 20 min before being homogenized with a stone mortar and pestle for 30 s. The placental tissue was then picked up with pre-cleaned stainless-steel tweezers to be weighed (∼0.6 g) into a new glass scintillation vial prior to digestion in 10 mL of 10% potassium hydroxide for 48 h, and shaken for 12 h at 300 rpm. Digestion and filtration procedures followed our previously published placental blood protocol (Bissonnette et al., 2025), adapted for placental tissue by including homogenization. Filtration was done with pre-cleaned GF/F glass fiber filters (diameter 47 mm, pore size 0.7 μm, Whatman, 1825–047). Detailed procedural steps are provided in Supplementary Material (Supplementary Text S1).

Instrumental analysis

Analysis was performed using a Waters Cyclic ion mobility mass spectrometer (United Kingdom) coupled to an Agilent 8890 gas chromatograph (United States) using atmospheric pressure chemical ionization (APCI) in positive mode. A Gerstel pyrolysis module (United States) coupled with a Thermal Desorption Unit was fitted to the GC inlet using a CIS4-cooled injection system. Calibration and spiking standards were prepared for: PE, PP, PS, PMMA, and PET with 13 C-labelled PS as an injection standard. These polymers were chosen because they are widely produced, environmentally prevalent, and have been previously reported in the placenta (Ragusa et al., 2021; Braun et al., 2021; Ragusa et al., 2022; Amereh et al., 2022; Zhu et al., 2023; Liu et al., 2023; Weingrill et al., 2023; Halfar et al., 2023; Zurub et al., 2024a; Garcia M. A. et al., 2024; Yun et al., 2024; Sun et al., 2024; Zhu et al., 2024; Oliveira et al., 2025; Zhang et al., 2025). Additional instrumental parameters and standard preparation are provided in Supplementary Text S2.

Quality assurance/quality control

In alignment with recommendations of Lamoree et al. (2025) and established principles for contaminant analysis (Richardson and Ternes, 2022), we implemented strict quality control procedures including plastics-free collection vials, method blanks [negative controls, one per participant (n = 46)], procedural blanks (n = 5), assessment of analytical recovery (positive controls), filtration in clean room (ISO Class 6) and matrix interference. The method targeted unique quantifier ions for PE, PP, PS, PMMA and PET identified previously (see Supplementary Table S3), (Bissonnette et al., 2025) with retention time, drift time, and collision cross section (CCS) values consistent with authentic standards (within ±0.03 min, ±0.50 ms and ±1%). Limit of detection (LOD) and quantification (LOQ) were calculated using standard equations (Supplementary Equations S1, S2), and MNP concentrations were blank-corrected through subtracting the mean of the method blanks (n = 46). Recovery, matrix effects, and precision were evaluated using fortified placental tissue samples (n = 3) that were spiked with 2 µg of PS, PE, PP, PMMA and PET standards before digestion. Quantification was compared using external, internal, and matrix-matched calibration curves (Supplementary Table S4). The matrix-matched calibration curves were created through spiking calibration standards onto placental tissue samples after they were digested, filtered and in pyrolysis tubes.

Data processing

Data was processed using Waters MassLynx v4.2. TargetLynx was used for quantitative analysis, and Driftscope v3.0 was used to visualize ion mobility and chromatographic contour plots. Progenesis QI was used to determine CCS values. All statistical tests were conducted using the R statistical software (http://www.r-project.org).

Comparison to pregnancy outcomes

To identify potential associations between total plastic concentration and pregnancy outcomes (neonatal birth weight, placental weight, feto-placental weight ratio), we used linear-mixed effects model to analyze the variation in pregnancy outcomes with the total plastic concentration natural log-transformed as the fixed effect, and the participant ID as the random variable (to account for repeated measurements). The study of MNP exposure and pregnancy outcomes is an emerging field of research, and data linking exposure to pregnancy complications remains sparse. Therefore, we performed an exploratory analysis using one-way ANOVAs to investigate whether there is a relationship between total plastic concentration in the placenta and pregnancy complications, across the full dataset and stratified by fetal sex. Statistical significance was defined as a p < 0.05, and comparisons trending towards significance (0.05 < p < 0.10) also reported (Thiese et al., 2016). As this study was exploratory, no prior sample size calculation was performed, and the sample size was based on the available placental samples at the time.

Clinical characteristics and placental morphology

The maternal demographics, pregnancy outcomes, and placental morphology for the 46 participants are summarized in Supplementary Table S5. All deliveries were via Cesarean section (one was an emergency Cesarean delivery for abnormal fetal tracing, and the rest were planned (e.g., previous Cesarean, breech presentation)). Nine participants met criteria for complicated pregnancies. All the placentas had normal weights, three-vessel cords, and normal membrane insertions. Three participants had a marginal cord insertion (<2.0 cm from the placental edge) (Khong et al., 2016), and there were no other gross morphological abnormalities. Further details are provided in Supplementary Text S3.

Confirmation of polymer identity by ion mobility

Targeted analysis of MNPs using Py-GCxcIMS requires careful selection of a unique quantifier ion for each polymer (Supplementary Table S3) to distinguish other polymers and interferences from the placental tissue matrix. The added value of using ion mobility in MNPs quantification is highlighted in Supplementary Figures S1, S2. PE is characterized by m/z 446.485 (C 32 H 62 •+), a retention time of 10.21 min, drift time of 42.91 ms and a CCS value of 237.5 Å 2. The extracted ion chromatogram in Supplementary Figure S1b displays a peak that could be mistaken for the genuine detection of PE. However, Supplementary Figure S1e shows that the same signal is characterized by a drift time (44.69 ms vs. 42.91 ms) and CCS value (244.5 Å 2 vs. 237.5 Å 2) that significantly deviate from expected values, indicating that it originates from matrix interference. On the other hand, Supplementary Figure S1f shows an example of a genuine detection of PE in a placental tissue sample: the m/z, retention time, drift time and CCS all closely match expected values. Three samples from two participants showed interferences for PE, all other samples were found to be genuine detections.

To further confirm that the detected signals ascribed to PE and PP are genuine and not matrix interferences, several pyrolysis decomposition products were monitored. When PE and PP are pyrolyzed, they break into unsaturated hydrocarbons with the general formula C x H 2x-2 and form molecular ions M•+ through charge exchange under APCI conditions (Hashemihedeshi et al., 2024). Biological matrixes contain lipids that can produce the same pyrolysis products as PE but typically have shorter chain lengths <C20 (Rauert et al., 2022). Recently, Tan et al. recommended examining the entire pyrogram and confirming the presence of less-common/more-unique oligomers C30 or higher when identifying PE (Tan et al., 2026). The extracted ion chromatograms for C 16 H 30 •+ to C 40 H 76 •+ obtained from a PE standard (Supplementary Figure S3a) were compared to those from a placental tissue sample (Supplementary Figure S3b). The peak profile below C30 showed considerable discrepancies between the standard and the placental tissue sample, which suggests that matrix effects can complicate identification. Conversely, the peak ratios observed between neighboring C30 to C55 homologues are within 20% of the expected values, see Figure 1, supporting the genuine detection of PP and PE.

Determination of MNP concentrations

The mass concentrations of PE, PP, and PS were quantified using linear internal calibration curves. PMMA and PET where characterized by low recoveries (<10%) and were not quantified. Internal calibration curves for PE, PP, and PS showed acceptable linearity (R 2 > 0.98; Table 1; Supplementary Figure S4). Recoveries of PE, PP, and PS were evaluated by fortifying placental matrix with 2 μg of each polymer and quantified using three different calibration schemes, as summarized in Supplementary Table S6; Supplementary Text S4. Blank-corrected LODs, LOQs, concentrations, and detection frequencies are summarized in Table 1. MNPs were detected above the LOD in 26% (24/92) of placental tissue samples and in 41% (19/46) of participants. Plastics were detected above the LOQ in 8% (7/92) of placental tissue samples and 13% (6/46) of participants. PP was the most common polymer, with a detection frequency above the LOD in 15% (14/92) of samples, followed by PE 10% (9/92) and PS 8% (7/92). The concentrations detected in the samples are shown in Figure 2; Supplementary Table S7.

There were no associations between total plastic concentrations and neonatal birth weight (p = 0.5), placental weight (p = 0.8) or feto-placental weight ratio, a measure of placental efficiency (p = 0.8). The total concentration of plastics was not significantly different between normal pregnancies and complicated pregnancies (p = 0.16). However, when separated into male and female neonates, there was a trend towards total concentration of plastics being significantly elevated in males from complicated pregnancies compared to normal pregnancies (p = 0.071) and not in females (p = 0.7).

In this study, Py-GCxcIMS was used to quantify plastics in human placental tissue. PE, PP, and PS were detected in 41% of 46 participants, with concentrations ranging from 0.1 μg/g to 12.3 μg/g. The mean of total plastic concentration was 1.8 μg/g with only values > LOD, whereas assigning values <LOD as zero yielded a mean of 0.5 μg/g. The sample with the highest concentration is an outlier (>4 times the standard deviation above the mean) and, while it is not the result of methodological issues or contamination, it is unknown whether this is related to environmental factors. However, if we decided to exclude this data point the mean of MNP concentration would reduce by 27% (1.8 to 1.3 μg/g) and the range would be narrowed from 0.1–12.3 μg/g to 0.1–4.4 μg/g. Out of the 92 placental tissue samples analyzed (46 participant in duplicate), 24 samples had detectable levels of MNPs (>LOD) and 7 samples had quantifiable levels of MNPs (>LOQ). If the values only <LOQ were assumed to be zero the total plastic polymer concentration in the present study would be 0.2 μg/g which is consistent with reported concentrations in human blood measured using Py-GC/MS (0.1–1.6 μg/mL) (Leslie et al., 2022; Brits et al., 2024; Bissonnette et al., 2025). Comparisons to maternal blood are informative, since the placenta is vascularized by maternal circulation and may act as a site of particle transfer. Direct comparison with prior placental studies is difficult because most used spectroscopic techniques, not intended to be quantitative, with no direct information about mass concentration. Reported particle counts of MNPs via spectroscopic techniques vary (1.0 MPs/g to 153.1 MPs/0.4 g) (Liu et al., 2023; Garcia M. A. et al., 2024). These techniques are often limited by size >1 μm and subject to spectral interferences (Azari et al., 2024), likely underestimating the total amount of plastic.

Py-GCxcIMS allows for the determination of mass concentrations. To date, one other study used Py-GC/MS to quantify MNPs in placental tissue (Garcia M. A. et al., 2024). Compared to Garcia et al., our mean concentration was significantly lower (1.8 μg/g vs. 126.8 μg/g), which seems to be driven by PE (0.35 μg/g vs. 68.8 μg/g) (Garcia M. A. et al., 2024). Ion mobility results showed that 25% (3/12) of PE detections in placental tissue were false positives, removed from the reported concentrations. A similar phenomenon was reported in human blood samples, where 45% (10/22) of the PE detections were identified as false positives. Even after removing these interferences, PE concentrations decreased by only 28% and total MNP concentration by 11%, suggesting that false positives alone cannot account for two orders of magnitude difference reported by Garcia M. A. et al. (2024). Variability in reported MNP concentrations between studies has been widely recognized and may reflect differences in sample collection, preparation, analytical methods and QA/QC procedures rather than true differences in tissue burden alone (Lamoree et al., 2025).

Geographic location is known to impact exposure levels to environmental pollutants (Chen et al., 2018; Giri et al., 2023). MNP concentrations vary across countries (Miranda-Peña et al., 2023), and have been detected in both terrestrial and aquatic environments in Newfoundland and Labrador (Liboiron et al., 2020). Differences in regional dietary patterns may also contribute to variation in MNP exposure between cohorts (Rafiq and Xu, 2026). However, Newfoundland is an island with a low population density (4.85/km 2) (Statistics Canada, 2023) and population density has been positively correlated with MP concentration in air, water, and sediment (Napper et al., 2023). Canadians spend ∼90% of their time indoors, (Health Canada, 2025) where inhalation of MNPs from indoor air and dust are recognized exposure pathways (Hashemihedeshi et al., 2024; Zuri et al., 2023), suggesting that indoor environments may contribute substantially to MNP exposure regardless of geographic location.

The mechanisms underlying accumulation of MNPs in the human body are still being investigated. Animal studies have provided some valuable information. For example, Huang et al. have shown that MNPs in the cerebral bloodstream in mice can be phagocytosed by cells and can obstruct the capillaries and accumulate in the tissue (Huang et al., 2025). In pregnant mice, Yang et al. showed polystyrene NPs delivered by intragastric gavage accumulate in the decidua and labyrinth zone of the placenta and can cross the placental barrier and reach the fetal brain (Yang et al., 2022). This is supported indirectly by detection of MNPs (e.g., PE, PP, PS) in meconium in human newborns (Braun et al., 2021; Liu et al., 2023).

Of the three plastic polymers quantified in this study, PP was the most frequently detected. This aligns with global scale of its production and use (Plastics - the fast Facts, 2024). Extensive applications in packaging, textiles, automotive, construction, and biomedical devices (Hossain et al., 2024) increases the likelihood of PP entering the environment and consequently the human body, explaining its high prevalence in placental tissue. Consistent with this, several studies reported PP in human placenta (Ragusa et al., 2021; Ragusa et al., 2022; Amereh et al., 2022; Zhu et al., 2023; Liu et al., 2023; Weingrill et al., 2023; Garcia M. A. et al., 2024; Yun et al., 2024; Sun et al., 2024; Oliveira et al., 2025; Zhang et al., 2025; Zurub et al., 2024a), maternal blood (Leslie et al., 2022; Brits et al., 2024; Bissonnette et al., 2025), and meconium (Liu et al., 2023; Zhu et al., 2024). Despite this, experimental evidence from animal studies regarding potential impacts on pregnancy remain limited. Huang et al. (Huang et al., 2025) is the only study directly assessing PP exposure during pregnancy. In mice, early life PP NPs exposure demonstrated that they crossed the placental barrier, impairing neuronal differentiation, proliferation, and lasting behavioral changes in offspring (Huang et al., 2025). These findings suggest maternal PP exposure can negatively impact fetal neurodevelopment, yet the lack of animal studies examining PP exposure during pregnancy reveals a lack of understanding its possible impacts on fetal development and maternal health.

PS was characterized by the highest mean concentration. Although only the 6th most produced plastic worldwide, (Plastics - the fast Facts, 2024) its lightweight nature supports diverse uses, and it is highly persistent and resistant to degradation (Yousif and Haddad, 2013; Singh and Sharma, 2008). Its low density could explain its frequent detection in air and dust samples (Hashemihedeshi et al., 2024). Much of the work using animal models to study the impact of MNPs on human health has used pristine PS particles. In mice, PS MPs have been shown to cross the gut barrier and enter multiple organs (Garcia M. M. et al., 2024), while PS NPs can cross the placental barrier and enter fetal organs (Jeong et al., 2022). Maternal MNP PS exposure through drinking water in mice resulted in fetal growth restriction (Aghaei et al., 2022a; Chen et al., 2023), induced early embryo loss (Wan et al., 2024), altered placental blood flow (Dibbon et al., 2024), abnormal placental and fetal brain metabolism (Mercer et al., 2023; Aghaei et al., 2022b), and postnatal structural brain abnormalities (Harvey et al., 2023). Compared to plastic in the MP size range, PS NP exerted more pronounced impact on fetal growth and placental hemodynamics. The impact of maternal PE exposure has been understudied, with one study showing it results in abnormal placental function in mice (Hanrahan et al., 2024).

There was a trend towards positive association between total concentration of plastic and pregnancy complications in male, but not female neonates. Most placental MNP studies only included healthy pregnancies (11/15 studies) and did not separate the data based on neonatal sex. In a cohort of both healthy pregnancies and pregnancies complicated to IUGR, Amereh et al. found a negative correlation between the number of MP particles and measurements of fetal wellbeing (e.g., birth weight, birth length, and 1-min Apgar score) (Amereh et al., 2022). We did not observe a similar association with birth weight in the present study. However, only one case of a small for gestational age (SGA) neonate was sampled. Placental adaptations and responses to in utero environmental changes have been shown to be dependent on fetal sex (Meakin et al., 2021). Male fetuses are more vulnerable to environmental pollution including per-/polyfluoroalkyl substances (Yu et al., 2021), heavy metals (Singh et al., 2018), and pesticides (Comfort and Re, 2017). Studies in areas of high exposure to petrochemical, polymer, and chemical industrial plants report a dramatic decline in the number of live male births (Mackenzie et al., 2005). MNPs and their additives have endocrine-disrupting effect (Vandenberg et al., 2017; Fowler et al., 2025), and may partially explain an association between high plastic concentrations and pregnancy complications in males.

A limitation of the study is the small sample cohort of 46 participants and a small number of pregnancy complications (n = 9). Larger cohorts will allow further exploration of the association of total plastic concentration with pregnancy complications and will allow separation into individual complication types. Another limitation to this study is that there was no lifestyle data collected from participants, therefore we were unable to explore links between environment or daily habits and MNP concentration in the placenta. Our study is also limited to plastic particles retained by filters with pore sizes >0.7 μm, potentially excluding smaller, more abundant particles. Rauert et al. (Rauert et al., 2025) demonstrated that NPs as small as 0.4 μm were captured on 0.7 μm filters, likely due to aggregation or matrix interactions. Finally, participants were recruited from Newfoundland and Labrador (Canada) and the generalizability to other parts of the world may be limited.

A strength of this study was duplicate tissue measurements analyzed separately, providing robust evaluation of plastic concentrations within the heterogeneous placenta. Variability in polymer type and concentration between samples from the same participant was observed (Figure 2; Supplementary Table S7), with a range of total MNP concentrations observed of 0.1–12.3 μg/g. This is consistent with the variability observed in Zurub et al. and likely reflects the natural heterogeneity of the placenta and highlighting the importance of large sample numbers from each placenta for accurate exposure assessment (Zurub et al., 2024a). Similar heterogeneity was observed in the duplicate measurements of MNPs in human blood (Leslie et al., 2022; Bissonnette et al., 2025). Py-GCxcIMS proved to be a sensitive approach for quantifying multiple polymers in complex biological matrixes while minimizing false positives. These findings establish a foundation for larger scale studies incorporating multiple sampling sites per placenta, expanding detectable polymers, and investigating potential associations with maternal and fetal health.

In summary, Py-GCxcIMS allowed the detection of MNPs in human placenta from 46 pregnant people in Newfoundland, Canada. This method improves true detection of PE, which can be falsely reported due to the presence of lipids and matrix interference. MNPs were present in 41% of participants, a mean concentration of 0.5 μg/g across participants was observed. PP was the most common polymer, and PS had the highest mean concentration. To date, only one animal study has studied the impact of PP exposure on pregnancy (Huang et al., 2025), but we hope this work will motivate future studies focused on this polymer type. Increasing evidence demonstrates that pregnant people are exposed to MNPs and that MNPs are present in the human placenta. Future studies should continue to work towards robust analytical methods for analysis of MNPs and include clinical studies of large populations to understand the associations with placental health and pregnancy outcomes.