Nanoparticles Are in Our Food, Clothing and Medicine -- And No One Knows for Sure How Dangerous They Might Be
Looking a lot like the government bad guys in E.T., the two men cautiously hover over a row of boxes containing native sedges, water grasses, and Zebra fish to spray a fine mist of silver nanoparticles over them. Their goal: to investigate how the world inside the boxes is altered by these essentially invisible and notoriously unpredictable particles.
The researchers are part of a multidisciplinary coalition of scientists from Duke, Stanford, Carnegie Mellon, Howard, Virginia Tech, and the University of Kentucky, headquartered at Duke’s Center for the Environmental Implications of NanoTechnology (CEINT), that represents one of the most comprehensive efforts yet to measure how nanoparticles affect ecosystems and biological systems.
So far the questions about whether nanoparticles are an environmental risk outnumber the answers, which is why the Duke scientists take the precaution of wearing clean-suits while dosing the boxes—no one’s sure what exposure to a high concentration of nanoparticles might do. Among the few things we do know about them are that they sail past the blood-brain barrier and can harm the nervous systems of some animals.
The regulation of nanoparticles has been recommended for more than a decade, but there’s no agreement on exactly how to do it. Meanwhile, the lid has already been lifted on nanotechnology. The use of man-made nanoparticles has spread into almost every area of our lives: food, clothing, medicine, shampoo, toothpaste, sunscreen, and thousands of other products.
Regulatory structures, both here and abroad, are completely unprepared for this onslaught of nanoproducts, because nanoparticles don’t fit into traditional regulatory categories. Additionally, companies often shield details about them by labeling them “proprietary”; they’re difficult to detect; we don’t have protocols for judging their effects; and we haven’t even developed the right tools for tracking them. If nanotechnology and its uses represent a frontier of sorts, it’s not simply the Wild West—it’s the Chaotic, Undiscovered, Uncontrollable West.
And yet, when I visit the boxes on a warm spring day filled with the buzzing of dragonflies and the plaintive call of mourning doves, they look perfectly benign and could easily be mistaken for a container garden. But there are hints that more is going on: each “mesocosm” (a middle ground between microcosm and macrocosm) is studded with probes and sensors that continually transmit data to CEINT’s central computer.
As I instinctively squint my eyes to try and locate evidence of the silver nanoparticles inside each box, I realize I might as well be staring down at these research gardens from another arm of the galaxy. The scale of these two worlds is so disparate that my senses are destined to fail me.
As with many things that are invisible and difficult to understand—think subatomic particles such as the Higgs boson, muons, gluons, or quarks—any discussion of nanoparticles quickly shifts into the realm of metaphor and analogy. People working in nanoscience seem to try to outdo each other with folksy explanations: Looking for a nanoparticle is like looking for a needle in the Grand Canyon when the canyon is filled with straw. If a nanoparticle were the size of a football, an actual football would be the size of New Zealand. A million nanoparticles could squeeze onto the period at the end of this sentence.