New method to detect nanoplastics in human blood

The accumulation of plastics in the environment is a growing concern around the world. Its effects on a macrometer scale are often seen, although the impact of the smallest plastic particles on our health has not yet been fully investigated. Exposure to microplastics and nanoplastics derives from life activities such as ingestion of food and water, and inhalation. It is necessary to be able to identify and measure them, as well as to identify what toxic effects they cause in living organisms.

In a recent study, flow cytometry has been used for the first time to detect and quantify nanoplastics in human peripheral blood. Research has been done on people with very different diseases to study possible differences in their accumulation. Mice from a highly controlled environment have also been used to compare their levels of nanoplastics with those of humans.

The study was carried out by a team that includes experts from the Germans Trias i Pujol Research Institute (IGTP), linked to the Catalan Institute of Oncology (ICO) and the Autonomous University of Barcelona (UAB), the Blood and Tissue Bank (BST), the Institute for Research in Biomedicine of Lleida (IRBLleida), the Hospital Sant Joan de Déu Barcelona, ​​Thermo Fisher Scientific and Sartorius Stedim North America.

In this study, Roser Salvia (UAB) and colleagues have used fluorescence and nanocytometry techniques, together with Nile red dye staining, to demonstrate that nanoplastics in blood can be detected using flow cytometry. It is a fast, precise and highly reproducible methodology, which becomes a valuable tool for future studies on exposure to plastics in humans. The study authors have evaluated the accumulation of nanoplastics in seven mice and in a cohort of 196 people, including regular blood donors, infants, and patients with hematologic and non-hematologic conditions.

The results demonstrate the presence of these particles in all the individuals analysed, both humans and mice. The levels of the human subjects are very varied in all the groups; the highest have been found in patients with acute lymphocytic leukemia and the lowest, in pediatric patients with type 1 diabetes. Regarding the differences by age, a decrease from 40 to 90 years has been found, so the accumulation of nanoplastics in tissues such as adipose could be a possibility.

Some disposable plastic cups can release trillions (millions of millions) of nanoparticles. The US National Institute of Standards and Technology (NIST) conducted research on this, published in 2022. (Image: N. Hanacek / NIST)

The researchers have taken advantage of studying people who live in the Barcelona metropolitan area, an urban area with air pollution problems and where exposure to plastic particles is high, to compare their levels of nanoplastics with those of mice under highly controlled. Analysis of mice at the Center for Comparative Medicine and Bioimaging of Catalonia (CMCiB) shows significantly lower levels in these animals than in humans, suggesting that inhalation of plastics could play a much larger role than previously thought. until now. It will therefore be necessary to explore the accumulation of plastics in rural and remote populations in future studies.

Dr. Jordi Petriz, from the IGTP Functional Cytomics laboratory and principal investigator of the study, highlights the importance of this work to “understand how exposure to plastic particles affects us and how they accumulate over time.” He values ​​flow cytometry as a “new technology to detect nanoplastics accurately and at the same time easily”. Finally, he points out that “more studies need to be carried out to determine the association between contamination from nanoplastics and health.”

The study is titled “Fast-screening flow cytometry method for detecting nanoplastics in human peripheral blood”. And it has been published in the academic journal Methods X. (Source: UAB. CC BY NC 4.0)