Discovery of microplastics and nanoplastics in pediatric myocardium and blood

Microplastics and nanoplastics (MNPs) are emerging environmental contaminants with potential health implications. Previous research has detected the existence of MNPs in the bloodstream and cardiac tissue of adult individuals, yet their presence and impact in pediatric populations remain largely unexplored. This study aimed to describe the concentration of MNPs in pediatric patients’ myocardium and blood samples. A total of 27 pediatric patients, along with 3 mothers, were included, who provided 27 samples of the myocardium, 7 pairs of pre- and post-surgery venous blood samples, and 3 pairs of the placenta and umbilical cord blood samples. Quantification of 9 kinds of MNPs was achieved using Pyrolysis-gas chromatography coupled with mass spectrometry (Py-GC/MS). The Laser Direct Infrared (LDIR) system was used to measure the size of MNPs. Four types of MNPs were identified by Py-GC/MS in the myocardium, including polyethylene (PE) (27/27, 100 %), Polystyrene (PS) (26/27, 96.3 %), polypropylene (PP) (22/27, 81.5 %), and polyvinyl chloride (PVC) (23/27, 85.2 %). The median concentration of total MNPs was 38.4 (IQR 27.4, 57.0) μg/g. Patients with 0-day of age (Immediately after birth) had the highest levels of MNPs in the myocardium. Mothers’ placenta and umbilical cord blood samples had the same types of MNPs with neonates’ myocardium and pre-surgery blood. The concentration of MNPs in post-surgery blood was higher than that in pre-surgery blood (3.54 ± 1.50 μg/g vs. 7.62 ± 2.99 μg/g, p = 0.007). Additional investigation is required to understand the origins and metabolic networks of MNPs and establish the method by which MNPs harm the cardiovascular system of youngsters.