Particulate contamination of human placenta: Plastic and non-plastic

Abstract Recent evidence indicates that the human womb is contaminated with a variety of particulate contaminants. Microplastics (MPs, tiny plastic particles ( < 5 mm) generated by the breakdown of larger plastic products in the environment) accumulation in human placenta has recently been described. In addition, recent evidence has correlated the number of air pollution particulates in term placentas to the loading of these particles in dust from the gestational parent home. The current study sought to characterize the accumulation of plastic and non-plastic particles (NPP) within the term human placenta. Placenta tissues were collected from healthy, singleton pregnancies following vaginal (n=5) and caesarean section (n=5) deliveries at a tertiary care centre located in an urban Canadian city (Ottawa, ON), with particles detected and characterized by Raman micro-spectroscopy. Both plastic and non-plastic particles were identified in all placentas examined, with an average of 1 ± 1.2 MPs /g and 4 ± 2.9 NPP /g of tissue. Similar tissue concentrations of MPs and NNP were identified in all regions of the placenta (basal plate, chorionic villous, chorionic plate), and did not differ according to mode of delivery. MPs ranged in size (2 - 60 μm), with the most abundant MPs being polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC). The most abundantly identified NPP were carbon, graphite, and lead oxide. Collectively, these results demonstrate the accumulation of foreign particles, including MPs, throughout the human placenta. Given the vital functions of the placenta in supporting fetal growth and development, and a potential for MPs to induce toxicity, further investigations into the potential harmful effects of these environmental toxicants on maternal and fetal health is warranted. Graphical Abstract Highlights Both plastic and non-plastic foreign particles were observed in term placentas from Canadian women Placenta contamination with most of the non-plastic particle types observed has not previously been reported. Particles were observed in similar frequency in placenta regions corresponding to maternal or fetal circulation suggesting that particles pass unhindered through the placenta.