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Small, broken down microplastics have already been found placentas, breast milksperm, and possibly even our brains. It’s still unclear what exactly all that debris does, but some experts fear it could contribute to dozens of health problems. Despite their increasing prevalence, scientists do not know exactly what causes these microplastics to break down in the first place. However, a new approach using 3D imaging to peer inside these particles could help provide a more robust understanding of how these microplastics break down.
A new one study published this week in the journal Nanotechnology uses a combination of traditional 2D microscopy and a 3D imaging technology normally used to view cells and macromolecules to observe the degradation of plastics in more detail than previously possible. Until now, researchers observing micro- and even smaller nanoplastics have been limited to X-rays and other two-dimensional surfaces. Using a process called electron tomography, the researchers in the study were able to see multiple cross-sections of the particles and their interiors. This revealed small differences in the way micro- and nanoplastics are broken down.
“This knowledge is crucial for developing more effective methods for degrading plastics at the micro and nanoscale,” said Professor Boxin Zhao of the University of Waterloo in a statement.
3D image shows provide a glimpse into refracting plastics
For their tests, the researchers had to find a way to quickly simulate how plastics might break down in the wild. To do that, they took samples of micro- and nanoplastics in petri dishes and treated them with UV light and a titanium oxide catalyst. This photocatalytic process allowed them to observe the materials as they broke down. Before that process, the researchers used a transmission electron microscope to take many images of the samples as they rotated in multiple directions. The electron tomography imaging technique is similar to that used in CT scans and is also used to observe defects in crystals at the atomic level.
3D view inside of microplastic
The flat part is the supporting film to which the nanoplastic is attached. The lumpy part is the nanoplastic. As it spins, you can clearly see the entire surface of this piece of nanoplastic. – University of Waterloo
When the researchers compared the 3D images of the broken down microplastics to a control group, the researchers saw that they tended to fragment into sharp, jagged breaking points. They theorized that this degradation could be the result of cracking in the plastic particles. In contrast, the degraded nanoplastic samples were more rounded and less broken along sharp edges. What exactly that means in terms of how plastics break down in the environment still remains unclear, but the observations provide more details that could help guide future research.
3D view inside of nanoplastic
This image shows the view through the entire nanoplastic. It shows how much more clearly they can now examine every piece of a nanoplastic particle. – University of Waterloo
Microplastics are appearing in people all over the world
The emergence of research showing microplastics in human bodies comes during a period of massive plastic pollution worldwide. A United Nations analysis estimates that humans produce approximately 400 million tons of plastic waste annually. About 36% of all plastic produced is used for packaging and about 85% of that ends up in landfills or as unregulated waste. Traces of microplastics are ubiquitous and have been found virtually everywhere on earth people look for them. All that plastic breaks down and breaks down over time until it is reabsorbed into the environment and consumed by animals.
Although research into the adverse health effects of microplastics in humans is still ongoing, some researchers have suggested that it could contribute to a wider range of health problems such as inflammatory bowel disease, colon cancer, hormonal irregularitiesand even decreasing sperm count and hormonal irregularities. The presence of microplastics appears to persist regardless of gender, demographic and geographic differences. Research from 2022 shows that this is the same visible in breast milkwhich is especially concerning because babies are more sensitive to chemical contaminants.
The 3D imaging study researchers are hopeful that this new approach will support efforts to help reduce plastic degradation in the future. Several of the researchers involved in that study are also investigating a new “cycling method“where bacteria can potentially ingest microplastics and then convert them into a biopolymer that can be reused to make bags or other plastic materials.