A recent study has shown that nanoplastics – plastic particles smaller than 0.001 millimeters – affect the body's ability to absorb antibiotics, and may even lead to the growth of antibiotic-resistant bacteria.
Using complex models of the molecular structures of common, everyday plastics polyethylene (PE), polypropylene (PP), polystyrene (PS) as well as nylon 6,6 (N66), researchers from the University of Vienna, University of Bonn, and University of Debrecen, discovered that nanoplastics can bind at the molecular level with the antibiotic tetracycline, impairing or even fully blocking the body's ability to absorb parts of it.
Tetracycline is a common broad-spectrum antibiotic used to treat everything from syphilis to bacterial skin and lung infections. Simulated annealing involves heating molecules to excite them before cooling them to find their most stable state, e.g., the state in which molecules form again naturally. In this instance, after annealing, nanoplastic molecules are physically bound together with the molecules of tetracycline.
University of Vienna's Lukas Kenner theorizes that clumps of concentrated, unabsorbed antibiotics attached to the surface of nanoplastics could provide the perfect breeding ground for bacteria to become resistant to the medication.
"The binding was particularly strong with nylon," says Kenner while talking about the danger indoors. "The micro and nanoplastic load is around five times higher there [indoors] than outdoors. Nylon is one of the reasons for this: it is released from textiles and enters the body via respiration, for example."
Everyday products made from PE, PP, PS and N66 degrade into nanoplastics through sunlight exposure, chemical exposure, and just good old-fashioned physical abrasion – breaking down into pieces we never even see as we eat, drink and inhale them. Some we simply absorb through our skin.
The long-term effects of nanoplastics are not yet fully understood, as research on their impact on human health is still relatively new. Scientists are working to uncover their long-term effects not only on people but also on ecosystems like marine and terrestrial habitats.
What we do know is the minuscule size of nanoplastics can allow them to interact with our bodies on a cellular level, even able to pass through the blood-brain barrier, which is responsible for keeping foreign substances out, such as large molecules, toxins, and pathogens.
Hopefully we can find a simple solution to deal with micro and nanoplastics sooner rather than later. As it stands, tests earlier this year amongst three top US bottled water retailers showed an average of nearly a quarter million detectable pieces of nanoplastic per bottle.
The study was published in the journal Nature.
Source: Medical University of Vienna