(NHI Nanoblog) BOSTON — So there are carbon nanotubes in your cellphone. Not a big deal for you, since the super-small, ultralight cylinders are safely ensconced inside. But what happens to them when you toss away that old handset?
Jacqueline A. Isaacs, a professor at Northeastern University and the associate director of the Center for High-Rate Nanomanufacturing, is working on ways to predict it. It’s part of a larger effort to look at the full life cycle of a nano-product, as researchers, manufacturers and regulators grapple with the potentially large risks from these small substances.
At last week’s Fifth International Symposium on Nanotechnology, Occupational and Environmental Health, Isaacs talked about what might happen if a switch that uses single-walled carbon nanotubes, now in development, were to be placed in phones. (The conference is hosted by the University of Massachusetts Lowell and the school’s Center for High-Rate Nanomanufacturing and Toxics Use Reduction Institute.)
More than 100 million cellphones are thrown away each year. Some are are recycled, but the process of breaking them down into components isn’t likely to eliminate the nanotubes, she said. Many more are tossed in the trash — leaving the question open of how they’re finally disposed of. Incineration might release the tiny carbon cylinders; grinding or other efforts to break down the phone could also lead to airborne nanotubes. And what could happen if your outdated handset simply rots in a landfill?
Isaacs created a mathematical model to predict the outcome. While she’s still tweaking the numbers, at least some release is projected in even the best-case scenario. And that could be a problem, given the questions that have been raised about the cylinders’ tendency to get into the lungs.
Nanotechnology leverages super-small particles (a nanometer is a billionth of a meter) to create products with remarkable properties. These materials can make bike frames lighter and stronger and sunscreen more transparent on the skin, as well as new medical instruments and medicines that can save lives.
There is broad agreement that nanomaterials have lots of potential for a wide variety of applications. But shrinking these substances can change their properties; scientists are struggling to figure out whether, how and why that shift can make them dangerous in the process.
Cellphones are just one example, and many researchers who presented here are thinking about the cradle-to-grave scenarios (or, as one put it, the better scenario of cradle-to-cradle, with the emphasis on recycling everything).
Knowing what happens when a product is recycled, thrown away or destroyed is a key part of that understanding, Isaacs said. Looking at a life cycle means scrutinizing everything from how a product is manufactured and used to what the end of its usefulness looks like.
For example, when you bang your carbon nanotube-fortified tennis racket on the ground after your fifth double-fault, does that put your health at risk?
Having the answer, Isaacs said, would help guide developers and manufacturers toward safer products, maximizing the virtues of nano-enabled materials without putting anyone at risk.
