Nobody Knows What Nanoparticles Do -- Yet They Are in Your Food, Cosmetics, and Toys

It's a beautiful summer day. You pull on your stain-resistant cargo shorts and odor-resistant hiking socks, gulp down an energy-boosting supplement, slather yourself with sunscreen and head out for a ramble in the woods. Are you poisoning yourself? When you get home, you jump in the shower and toss your clothes in the wash. Are you poisoning the environment? Maybe.

Your sunscreen, energy drink and high-tech clothing may be among the 800-plus consumer products made with nanomaterials: those manufactured at the scale of atoms and molecules. Sunscreen that turns clear on the skin contains titanium dioxide, an ordinary UV-blocker in extraordinarily small particles. Odor-eating socks are made with atoms of germ-killing silver. Supplement makers boast of amazing health effects from swallowing nanosolutions that are completely untested for effectiveness or safety. And that stain-repellant clothing? The manufacturer won't even tell you what nanomaterials are in it.

The problem is not just that you, the consumer, don't know what's in the products you use. The much bigger problem is that at the nanoscale, common substances behave in uncommon ways. And nobody--not even the world's leading nanoscientists--knows what nanoparticles do inside the body or in the environment.

Nanotechnology, a fast-growing global industry, is essentially unregulated. Advocates and independent scientists agree that we need to get ahead of the risks before it's too late. Some call for a moratorium on the riskiest nanoproducts. Some say we just need more research, and more protection for workers in the meantime. All are worried about unleashing a powerful new technology that could have vast unintended consquences. Nanomaterials are in food, cosmetics, clothing, toys and scores of other everyday products. Yet when it comes to trying to get a handle on them, we can't answer the most basic questions. What companies are using nanomaterials, and where? What kinds, and in what amounts? How much of the potentially hazardous stuff is escaping into the air, water and soil? Into our food and drinks? Nobody knows.

At a February workshop on what research is needed to better understand nanorisks, speaker after speaker presented questions without answers. Rutgers University environmental scientist Paul Lioy, assigned to talk about human exposures to nanomaterials, was especially blunt.

"This is basically virgin territory," he said. "The fact that it's virgin territory is not good for the field, and it should be fixed really quick."

Big Benefits, Big Risks?

Nanomaterials are not new. Some exist naturally, and others result from combustion--like the ultrafine particles in diesel exhaust that have been linked to respiratory and heart diseases.

What's new is nanotechnology, the ability to manufacture and manipulate minuscule materials into forms such as quantum dots, spherical buckyballs, and cylindrical carbon nanotubes. These engineered nanomaterials take on unusual properties: changing color, for example, or becoming electrically conductive, or penetrating cell walls. And they have many uses. Carbon nanotubes, or CNTs--made by rolling up sheets of graphite just one atom thick--are extremely light and strong; they show up in high-end tennis rackets and bicycle frames. Nanosilver is used as an antimicrobial agent in everything from paint to toothpaste to teddy bears. Nanometal oxides are blended into ceramics and coatings, making them more durable.

While there's no universal definition, the "nano" moniker generally covers materials between one and 100 nanometers. A nanometer is one billionth of a meter, or between 50,000 and 100,000 times thinner than a human hair.

Nanotech offers enormous potential benefits. Medical researchers are investigating ways to use nanomaterials to target tumors and then deliver tiny amounts of drugs directly inside the cancer cells, sparing the healthy cells. Possible green tech applications include cheaper, more efficient solar panels and water-filtration systems, energy-saving batteries and lighter vehicles that use less fuel.

That's the upside. But exciting new wonder materials often reveal a dark side, too. Asbestos--now synonymous with bankrutpcy-inducing lawsuits and slow, painful death--was once seen as a miraculous fireproofing agent that would save millions of lives. Much of its damage could have been avoided if industry and government had heeded the ample danger signs. Now, early research on the potential hazards of nanotech is producing danger signs of its own. Workers handling nanomaterials face the biggest risks. But there are concerns for consumers, too, especially with products--like cosmetics, food and supplements--that go directly on or in the body. And with potentially toxic nanomaterials washing down the drain and into the water and soil, there's reason to worry about environmental damage as well.