Washing your hands well is important and possibly the most primary weapon in the battle against germs. By now, it would seem that almost everyone in the world knows about the necessity for proper handwashing, especially after using the restroom or a hospital. But then, what if the real problem comes thereafter?
“Of all the ways we can dry our hands after scrubbing down, the paper towel method tends to be the most hygienic,” says Tom Webster chemical engineering professor and chair at Northeastern University. In comparison to paper towels, he says “Air dryers can actually blow bacteria onto other surfaces, causing further contamination down the line. So, as we walk away all shimmery and dry, bacterial colonies begin to fester on the nearby sinks and paper towel racks we leave behind.” Nonetheless, other experiments have shown that participants actually walk away with more bacteria on their hands when they dry with paper towels than before they even washed up. “You can imagine where this might become an issue in places like the doctor’s office, hospitals, and restaurants,” adds Webster.
Paper towels that are discarded into bins, overtime start to form so-called biofilms, or impenetrable coatings of bacteria. For this reason, Webster decided to apply his work to developing anti-microbial medical devices to paper towels. He and his team coated paper towel fragments with nanoparticles of selenium, a non-metallic element. “We have seen that selenium interferes with proteins inside the bacteria causing them to die,” said Webster, referring to previous work.
These kinds of towels, that wouldn’t cost any more than normal towels, managed to stave off 90 percent of bacterial growth after 72 hours compared to uncoated towels, according to Webster. In the case of medical devices like catheters, which they are also working on, the additional costs are minor. And since mammalian cells actually need selenium to function properly, toxicity isn’t an issue. Finally, in that ongoing debate about antimicrobial resistance, Webster assured me that selenium is likely not to become a culprit. “This is because selenium acts in a different mechanism than antibiotics to kill bacteria,” Webster explained.