Micro- and nanoplastics (MNPs) are increasingly linked to human health outcomes such as to potential impacts on cardiovascular health. However, the mechanisms through which MNPs interfere with cardiovascular health have remained elusive. In an article published on December 6, 2024, in the journal Nature Scientific Reports, Dong-Wok Lee from Inha University, Incheon, South Korea, and co-authors analyzed MNPs in human blood and their association with the donors’ lifestyles and disruptions in blood coagulation.
The researchers analyzed blood samples from 36 healthy adults living in South Korea for the presence of MNPs and key blood coagulation markers. Participants also completed detailed questionnaires assessing lifestyle and demographics, including the use of ready-made meals and the percentage of plastic containers in their refrigerators. The team used Fourier-transform infrared (µ-FTIR) spectroscopy to quantify and identify plastic particles larger than 5 µm in the blood samples. When µ-FTIR failed to detect MNPs, they subjected the respective samples to µ-Raman spectroscopy, which is a more sensitive but also more time-consuming analysis method.
The µ-FTIR analysis demonstrates that 89% of the blood samples contain MNPs, with an average concentration of 4.2 particles/mL blood. Polystyrene (PS), polypropylene (PP), and polyethylene (PE) are the predominant plastic types detected. Notably, most MNPs detected in blood are between 20 and 50 µm in size. Due to their large size, the researchers suggest an uptake mechanism called “persorption”, where MNPs pass through small gaps in the intestinal lining to enter the bloodstream, rather than crossing the cell membranes directly.
Based on a very crude assessment of plastic food packaging consumption, the study results further indicate that participants with higher incomes and greater use of plastic containers are statistically more likely to have more MNPs in their blood. The authors hypothesized that ‘in South Korea, people with high incomes prefer bottled water to tap water, which could contribute to higher exposure to [MNPs]’. These findings align with previous research, suggesting that food and water stored in plastic containers are significant sources of MNP intake.
Importantly, the levels of MNPs in blood correlate with changes in blood coagulation markers. Specifically, higher MNP levels are associated with longer activated partial thromboplastin time (aPTT), a measure of how quickly blood clots, and lower antithrombin III levels, both of which indicate impaired blood clotting. In addition, MNP levels correlate with high-sensitivity C-reactive protein (hs-CRP), a marker for general inflammation, suggesting that MNPs may trigger inflammatory responses.
Although this study with a small sample size reveals strong connections between MNP levels and blood coagulation markers, the authors stress that further research is needed to uncover the underlying mechanisms. They emphasize “the need … to further investigate the health effects of [MNPs], especially with regard to blood coagulation and possible cardiovascular hazards.”
Reference
Lee, D.-W. et al. (2024). “Microplastic particles in human blood and their association with coagulation markers.” Nature. DOI: 10.1038/s41598-024-81931-9
Other recent research
Raffaele Marfella, et al. (2024) “Microplastics and Nanoplastics in Atheromas and Cardiovascular Events.” The New England Journal Of Medicine. DOI: 10.1056/NEJMoa2309822
