Microplastics detected in human blood linked to altered coagulation markers

By Priyanjana Pramanik, MSc.Reviewed by Lily Ramsey, LLMDec 10 2024

Research finds microplastics in human blood correlated with lifestyle habits and changes in coagulation markers, emphasizing the need to mitigate exposure and its health risks.

Study: Microplastic particles in human blood and their association with coagulation markers. Image Credit: SIVStockStudio/Shutterstock.com

In a recent study published in Scientific Reports, researchers investigated the impact of microplastics (MP) on blood coagulation.

Their findings indicate that higher MP concentrations in blood were linked to greater levels of markers of inflammation and coagulation, highlighting the urgent need to reduce microplastic exposure.

Background

Plastics are synthetic polymers derived from oil, gas, or coal and have become widely used because they are affordable, chemically stable, and easy to process. Global plastic production increased from 1.5 million tons to 390 million tons between 1950 and 2021, with usage rising 20 times in the past half-century.

MPs are small plastic particles (less than 5mm) that can come from larger plastics breaking down or being intentionally made small. Humans are exposed to these substances through inhalation, ingestion, and contact with skin, with MPs found in food, water, and everyday products like teabags and food packaging.

MPs have also been found in marine environments since 2004, with fears growing that there will be more plastic than fish in the oceans by 2050. Seafood consumption is a possible source of exposure for MPs.

MPs have been detected in human biological samples (including breast milk, lungs, liver, feces, and blood). They may cause physical toxicity, oxidative stress, inflammation, and immune reactions, potentially affecting the cardiovascular system.

Recent studies suggest that MPs in the bloodstream might impact coagulation and cardiovascular health, though research on this is limited.

About the study

In this study, researchers aimed to investigate the presence of MPs in blood and their potential association with coagulation markers and other health indicators. 36 healthy Korean adults aged 20 to 60, excluding those with psychiatric disorders, cancer, and liver disease.

Demographics and plastic-related lifestyle factors such as physical activity, consumption of seafood, and usage of plastic food containers were collected through questionnaires.

Participants’ blood was also collected and analyzed for MP content. The samples were tested for markers of inflammation and coagulation, such as fibrinogen, prothrombin time, and C-reactive protein.

Statistical analysis was used to examine how MP levels and coagulation markers interacted after considering other factors such as lifestyle, age, and sex.

Findings

36 individuals participated in the study, of whom 72% were female. On average, they were 41 years old, and the majority had a post-college or college education and held white-collar jobs. Most were physically inactive, consumed alcohol, and did not smoke.

Researchers found MPs in 32 of the blood samples. The average MP concentration was 4.2 MPs/ml, with 20 to 50 μm MPs being the most common size (75% of samples).

Fragments were more common than fibers (86.1% vs. 36.1%). There was no significant statistical link between the detection of MP and habits such as indoor ventilation, seafood intake, and ready-made meal consumption.

However, higher levels of MPs were found in those who had more than 50% plastic containers in their refrigerators (6.8 MPs/ml compared to 2.4 MPs/ml among those with less than 50%).

Analysis of the blood showed that the group with higher MP levels had significantly prolonged activated partial thromboplastin time (aPTT) compared to those with low MP levels.

There were also significant correlations between levels of MP and higher levels of fibrinogen (a marker for clotting) and C-reactive protein (a marker for inflammation). Platelet counts showed a marginal difference between low and high MP groups.

Conclusions

This study detected MPs in the blood of 32 out of 36 participants. The average MP concentration was 4.2 particles/ml, and most particles ranged between 20 and 50 μm.

MPs were more common in individuals with higher levels of education and those using more plastic containers in their refrigerators. Additionally, higher MP concentrations were linked to altered blood coagulation, including a prolonged aPTT and positive associations with inflammation markers like C-reactive protein and fibrinogen.

The study also highlighted a potential connection between MPs and cardiovascular risks due to changes in coagulation and inflammation.

Larger MPs might be absorbed through the gastrointestinal tract or introduced iatrogenically. The study found that MPs in blood could influence coagulation pathways, potentially leading to health risks, including cardiovascular diseases.

While the study had limitations, such as a small sample size and potential contamination, it suggests that MPs in blood are a concern, impacting coagulation and inflammation. The findings call for further research to understand the full effects of MP exposure on human health, especially concerning blood clotting and cardiovascular conditions.

Future studies should use more advanced methods to explore these associations further in other settings and populations.