Turns out, micro and nano plastics degrade differently. Credit: University of Waterloo
Small, degraded microplastics have already been found in placentas, breast milk, semen, and potentially even our brains. It’s still unclear exactly what all that debris is doing, but some experts fear it could contribute to scores of health problems. Despite their growing prevalence, scientists also aren’t exactly sure what causes these microplastics to degrade in the first place. A new approach using 3D imaging to peek inside these particles, however, could help provide more robust insight into just how these microplastics break down.
Researchers took numerous images of a revolving microplastic sample to get a glimpse into its interior. Credit: Credit: University of Waterloo
A new study published this week in the journal Nanotechnology employs a combination of traditional 2D microscopy and a 3D imaging tech normally used to view cells and macromolecules to observe the degradation of plastics in greater detail than previously possible. Until now, researchers observing micro and even smaller nanoplastics were limited to X-Rays and other two dimensional surfaces. By using a process called electron tomography, the researchers in the study were able to see multiple cross sectional views of the particles and their interiors. This revealed slight differences in the ways micro and nano plastic degrade.
“This knowledge is crucial for developing more effective methods of breaking down plastics on the micro and nanoscales,” University of Waterloo professor Boxin Zhao, said in a statement.
3D imaging shows offers a glimpse inside fracturing plastics
For their tests, the researchers needed to find a way to quickly simulate how plastics might degrade in the wild. To do that, they took samples of micro and nano plastics 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. Prior to 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 an atomic level.
3d view inside of microplastic
The flat part is the supporting film to which the nano plastic is attached. The lumpy part is the nano plastic. As it spins, you can clearly see the entire area of this piece of nanoplastic. – University of Waterloo
When the researchers compared the 3D-images of the degraded microplastics against a control, the researchers saw they tended to fragment in sharp, jagged break points. They theorized this breakdown could result from cracking forming within the plastic particles. The degraded nano plastic samples, by contrast, were more rounded and less broken along sharp edges. What exactly all that means in terms of how plastics breakdown in the environment still remains unclear, but the observations provide more details that could aid in future research.
3D view inside of nanoplastic
This image shows the view going through the whole nanoplastic. It demonstrates how much more clearly they can now examine every bit of a nanoplastic particle. – University of Waterloo
Microplastics are showing up in humans around the world
The rise or research showing microplastics in human bodies comes amid a period of immense plastic pollution worldwide. A United Nations analysis estimates humans produce around 400 million tons of plastic waste annually. Around 36% of all plastic produced ise used for packaging and around 85% of that ends up in landfills or as unregulated waste. Traces of microplastics are ubiquitous and have been found just about anywhere on earth humans look for them. All that plastic degrades over time and breaks down until it’s reabsorbed into the environment and consumed by animals.
Though research into the adverse health effects of microplastics in humans is still ongoing, some researchers have suggested it could be contributing to increased rates of health problems like inflammatory bowel disease, colon cancer, hormone irregularities, and even shrinking sperm counts and hormone irregularities. The presence of microplastics appears to persist across gender, demographic, and geographic differences. Research from 2022 revealed its even showing up in breast milk, which is especially concerning because infants are more susceptible to chemical contaminants.
The researchers in the 3D imaging study are hopeful this new approach will inform efforts to help mitigate plastic degradation moving forward. Several of the researchers involved in that study are also looking into a new “bicycling method” where bacteria could potentially ingest microplastics and then turn them into a biopolymer that could be reused to make bags or other plastic materials.
Source : Popular Science