(March 24) -- For almost two years, molecular biologist Bénédicte Trouiller doused the drinking water of scores of lab mice with nano-titanium dioxide, the most common nanomaterial used in consumer products today.
She knew that earlier studies conducted in test tubes and petri dishes had shown the same particle could cause disease. But her tests at a lab at UCLA's School of Public Health were in vivo -- conducted in living organisms -- and thus regarded by some scientists as more relevant in assessing potential human harm.
Halfway through, Trouiller became alarmed: Consuming the nano-titanium dioxide was damaging or destroying the animals' DNA and chromosomes. The biological havoc continued as she repeated the studies again and again. It was a significant finding: The degrees of DNA damage and genetic instability that the 32-year-old investigator documented can be "linked to all the big killers of man, namely cancer, heart disease, neurological disease and aging," says Professor Robert Schiestl, a genetic toxicologist who ran the lab at UCLA's School of Public Health where Trouiller did her research.
Benedicte Trouiller in an undated photo
Courtesy Benedicte Trouiller
UCLA molecular biologist Bénédicte Trouiller found that nano-titanium dioxide -- the nanomaterial most commonly used in consumer products today -- can damage or destroy DNA and chromosomes at degrees that can be linked to "all the big killers of man," a colleague says.
Nano-titanium dioxide is so pervasive that the Environmental Working Group says it has calculated that close to 10,000 over-the-counter products use it in one form or another. Other public health specialists put the number even higher. It's "in everything from medicine capsules and nutritional supplements, to food icing and additives, to skin creams, oils and toothpaste," Schiestl says. He adds that at least 2 million pounds of nanosized titanium dioxide are produced and used in the U.S. each year.
What's more, the particles Trouiller gave the mice to drink are just one of an endless number of engineered, atom-size structures that have been or can be made. And a number of those nanomaterials have also been shown in published, peer-reviewed studies (more than 170 from the National Institute for Occupational Safety and Health alone) to potentially cause harm as well. Researchers have found, for instance, that carbon nanotubes -- widely used in many industrial applications -- can penetrate the lungs more deeply than asbestos and appear to cause asbestos-like, often-fatal damage more rapidly. Other nanoparticles, especially those composed of metal-chemical combinations, can cause cancer and birth defects; lead to harmful buildups in the circulatory system; and damage the heart, liver and other organs of lab animals.
Yet despite those findings, most federal agencies are doing little to nothing to ensure public safety. Consumers have virtually no way of knowing whether the products they purchase contain nanomaterials, as under current U.S. laws it is completely up to manufacturers what to put on their labels. And hundreds of interviews conducted by AOL News' senior public health correspondent over the past 15 months make it clear that movement in the government's efforts to institute safety rules and regulations for use of nanomaterials is often as flat as the read-out on a snowman's heart monitor.
"How long should the public have to wait before the government takes protective action?" says Jaydee Hanson, senior policy analyst for the Center for Food Safety. "Must the bodies stack up first?"
Big Promise Comes With Potential Perils
"Nano" comes from the Greek word for dwarf, though that falls short of conveying the true scale of this new world: Draw a line 1 inch long, and 25 million nanoparticles can fit between its beginning and end.
Apart from the materials' size, everything about nanotechnology is huge. According to the federal government and investment analysts, more than 1,300 U.S. businesses and universities are involved in related research and development. The National Science Foundation says that $60 billion to $70 billion of nano-containing products are sold in this country annually, with the majority going to the energy and electronics industries.
FDA.gov
Both the promise and the potential peril of nanomaterials come from their staggeringly small size, which is highlighted by the chart above. (Note, for example, how it shows that the periods on this page are equal to 1 million nanometers.)
Despite the speed bump of the recession, a global market for nano-containing products that stood at $254 billion in 2005 is projected to grow to $2.5 trillion over the next four years, says Michael Holman, research director of Boston-based Lux Research. Another projection, this one from National Science Foundation senior nanotechnology adviser Mihail Roco, says that nanotech will create at least 1 million jobs worldwide by 2015.
By deconstructing and then reassembling atoms into previously unknown material -- the delicate process at the heart of nanotechnology -- scientists have achieved medical advancements that even staunch critics admit are miraculous. Think of a medical smart bomb: payloads of cancer-fighting drugs loaded into nanoscale delivery systems and targeted against a specific tumor.
Carbon nanotubes, rod-shaped and rigid with a strength that surpasses steel at a mere fraction of the weight, were touted by commentators at the Vancouver Olympics as helmets, skis and bobsleds made from nanocomposites flashed by. Those innovations follow ultralight bicycles used in the Tour de France, longer-lasting tennis balls, and golf balls touted to fly straighter and roll farther.
Food scientists, meanwhile, are almost gleeful over the ability to create nanostructures that can enhance food's flavor, shelf life and appearance -- and to one day potentially use the engineered particles to craft food without ever involving a farm or ranch.
Yet for all the technology's promise and relentless progress, major questions remain about nanomaterials' effects on human health. A bumper sticker spotted near the sprawling Food and Drug Administration complex in Rockville, Md., puts it well: "Nanotech -- wondrous, horrendous, and unknown."
Adds Jim Alwood, nanotechnology coordinator in the Environmental Protection Agency's Office of Pollution Prevention and Toxics: "There is so much uncertainty about the questions of safety. We can't tell you how safe or unsafe nanomaterials are. There is just too much that we don't yet know."
What is known is by turns fascinating and sobering.
Vial of carbon nanotubes
Courtesy Nanotechnology Project
The carbon nanotubes in this vial are part of a booming industry. According to one consulting firm, the global market for nano-containing products is projected to grow to $2.5 trillion by 2014.
Nanoparticles can heal, but they can also kill. Thanks to their size, researchers have found, they can enter the body by almost every pathway. They can be inhaled, ingested, absorbed through skin and eyes. They can invade the brain through the olfactory nerves in the nose.
After penetrating the body, nanoparticles can enter cells, move from organ to organ and even cross the protective blood-brain barrier. They can also get into the bloodstream, bone marrow, nerves, ovaries, muscles and lymph nodes.
The toxicity of a specific nanoparticle depends, in part, on its shape and chemical composition. Many are shaped roughly like a soccer ball, with multiple panels that can increase reactivity, thus exacerbating their potential hazards.
Some nanoparticles can cause a condition called oxidative stress, which can inflame and eventually kill cells. A potential blessing in controlled clinical applications, this ability also carries potentially disastrous consequences.
"Scientists have engineered nanoparticles to target some types of cancer cells, and this is truly wonderful," says Dr. Michael Harbut, director of the Environmental Cancer Initiative at Michigan's Karmanos Cancer Institute. "But until we have sufficient knowledge of, and experience with, this 21st-century version of the surgical scalpel, we run a very real risk of simultaneously destroying healthy cells."
When incorporated into food products, nanomaterials raise other troubling vagaries. In a report issued in January, the science committee of the British House of Lords, following a lengthy review, concluded that there was too little research looking at the toxicological impact of eating nanomaterials. The committee recommended that such "products will simply be denied regulatory approval until further information is available," and also raised the concern that while the amount of nanomaterial in food may be small, the particles can accumulate from repeated consumption.
"It is chronic exposure to nanomaterials that is arguably more relevant to food science applications," says Bernadene Magnuson, a food scientist and toxicologist with Cantox Health Sciences International. "Prolonged exposure studies must be conducted."
Given the potential hazards, public health advocates are calling for greater restraint on the part of those rushing nano-products to market. "The danger is there today in the hundreds of nano-containing consumer products being sold," says Jennifer Sass, senior scientist and nano expert for the nonpartisan Natural Resources Defense Council. "Things that are in the nanoscale that are intentionally designed to be put into consumer products should be instantly required to be tested, and until proper risk assessments are done, they shouldn't be allowed to be sold."
David Hobson, chief scientific officer for international risk assessment firm nanoTox, adds that the questions raised by the growing body of research "are significant enough that we should begin to be concerned. We should not wait until we see visible health effects in humans before we take steps to protect ourselves or to redesign these particles so that they're safer."
Hobson says that when he talks to university and industry nano scientists, he sometimes feels as if he's talking with Marie Curie when she first was playing around with radium.
"It's an exciting advancement they're working with," he says. "But no one even thinks that it could be harmful."
REST OF THE STORY
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