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http://www.emagazine.com/view/?4723

July/August 2009
Vol. XX, no. 3

COVER STORY

Tiny Troubles

How Nanoparticles Are Changing Everything From Our Sunscreen to Our Supplements

By Carole Bass

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.

Yet studies on nanotech's downside are a mere nanospeck compared to 
the research that's being done on how this technology can benefit 
humanity-and corporate profits. Of $1.5 billion in federal nano 
spending each year, only between 1% and 2.5% goes toward studying 
environmental, health and safety risks. Worse, there's no national 
strategy for deciding what questions need to be answered, or what to 
do with those answers as they arrive.

Occupational Hazards

Since the 17th century, when Italian physician Bernardino Ramazzini 
pioneered the field of occupational medicine, researchers have looked 
to the workplace for advance warning of new illnesses. From janitors 
blinded by ammonia fumes to chimney sweeps who absorbed 
cancer-causing soot through their skin, workers get sick first and 
most acutely because of their intense, daily toxic exposures. That's 
why much of the still-sparse nano health and safety research has 
focused on the possible hazards of working with nanomaterials. 
Scientists can't expose workers to potential toxins and watch to see 
if they keel over. But if employers cooperate, researchers can find 
out what materials workers are using, in what amounts and forms, and 
under what conditions. Then they can simulate those exposures with 
lab animals.

Some studies find little or no risk. Others are alarming. Last year, 
British researchers reported that when long, straight carbon 
nanotubes-shaped like asbestos fibers-were injected into mice, they 
caused the same kind of damage as asbestos. Of course, workers 
wouldn't ordinarily stick themselves with a needleful of CNTs. But a 
follow-up study this year, by the National Institute for Occupational 
Safety and Health (NIOSH), found that when mice inhaled CNTs, the 
tiny tubes migrated from their lungs to the surrounding tissue-the 
very spot where asbestos causes the rare cancer known as 
mesothelioma.   One reason nanomaterials can cause trouble is that 
they are small enough to evade the body's defenses. In a University 
of Rochester study of the accidental nanoparticles known as ultrafine 
pollution, they bypassed the protective blood-brain barrier and 
slipped directly into the brain's olfactory bulb. Other research 
demonstrates that nanomaterials can penetrate the deepest part of the 
lungs. From there, they cross into the bloodstream and various organs.

Based on evidence like this, the European Union's occupational health 
and safety agency issued an expert report in March, citing 
nanoparticles as the number-one emerging risk to workers. In the 
U.S., NIOSH has issued a guidance document urging employers to avoid 
exposing workers to nanomaterials-for example, by enclosing equipment 
and using ventilation to reduce dust and fumes. But NIOSH has no 
regulatory power; it can only suggest.

The Pig-Pen Effect

"You're producing a personal cloud of exposure," Paul Lioy warned. 
"Every time you breathe. Every time you move. If the materials you're 
wearing have [nano]materials that can be released, they will be 
released. It's basically the Pig-Pen effect.

Lioy, the Rutgers environmental scientist, was speaking 
theoretically. His audience was fellow scientists, gathered in 
Bethesda, Maryland, for a workshop sponsored by the federal 
government. The workshop's title: "Human & Environmental Exposure 
Assessment of Nanomaterials." Lioy's assignment: Talk about the need 
for research to "characterize exposure to the general population from 
industrial processes and industrial and consumer products containing 
nanomaterials." His message: There is no research on whether and how 
the general population is exposed to nanomaterials. Searching the 
scholarly literature, Lioy's associates "spent hours looking for data 
... and found nothing," he said.

While workers are on the front lines of nanoexposure, Lioy cautioned 
against ignoring consumer exposures. "We are all in contact with 
it-300 million of us, if we use products that have nanoparticles," he 
declared. And while nanomaterials that are embedded in a hard surface 
like a computer keyboard are probably not a big worry, clothing and 
cosmetics might be a different story, he said. That's where his 
comparison to Pig-Pen, the Peanuts character forever surrounded by a 
cloud of dirt, comes in: the idea that every time we move, 
nanoparticles might come loose from our moisturizer or our 
stain-resistant togs.

Noting that "a lot of nanoparticle uses are terrific," Lioy said he 
doesn't want society to do without. As scientists do the necessary 
studies, "I think a lot of issues will go away," he said. "I just 
don't want unintended consequences."

Down the Drain

Cyndee Gruden is getting the poop on nano-pollution-literally.

One of the main environmental concerns about nanomaterials is what 
happens when they wash out of clothing, hair or skin and go down the 
drain. Do they harm aquatic life? Do they interfere with wastewater 
treatment?

Gruden, a civil engineering professor at the University of Toledo in 
Ohio, is tackling part of that last question by looking at the 
effects of two nanometals-titanium dioxide and zinc oxide, used in 
sunscreens, paint and other products-on bacteria.

Metals "can be toxic to microorganisms," she notes. "In fact, that's 
specifically what they're for" in consumer products: to inhibit mold, 
mildew and other nastiness. But when nanometals make their way to a 
sewage treatment plant, Gruden worries that they might harm the 
beneficial bacteria that break down what's delicately known in the 
business as "biosolids."

Her preliminary findings, which she presented at a meeting of the 
American Chemical Society (an academic group, not an industry 
organization) in March, are mixed. Nano-titanium dioxide damaged 
bacteria, causing cell walls to break at "relatively low 
concentrations," similar to what you might see at a sewage treatment 
plant, Gruden says in an interview. But "in terms of function, what 
does that mean? Are the bugs able to do what they're supposed to do?"

To answer that question, she added some biosolids to her test tubes 
and measured how much methane the bacteria produced as they digested 
for five days. The titanium dioxide didn't seem to slow the bugs 
down; in fact, methane production actually increased. But when Gruden 
added nano-zinc oxide, gas production slowed down. She's running more 
experiments this summer to see what happens when the bacteria are 
exposed to the bugs for a full 30 days.

"The take-home message for me is, the behavior of these particles is 
very complex," Gruden says. "When you take a nanoparticle and put it 
into the environment, you have to know how it's going to behave. And 
we don't."

One metal Gruden didn't look at is nanosilver, widely used as a 
microbe-killer. The Project on Emerging Nanotechnologies, a nonprofit 
research and advocacy organization funded by the Pew Charitable 
Trusts in Washington, D.C., maintains an inventory of more than 800 
consumer products advertised as using nanotechnology. Silver is by 
far the most frequently identified material.

In an experiment publicized last year, Arizona State University 
graduate student Troy Benn bought nanosilver-containing socks off the 
Internet and simulated washing them in jars of water. He found that, 
for several brands, most or all of the silver disappeared in just a 
few washings. Silver has been used to kill bacteria since ancient 
times, when the Greeks found that wine stayed fresh longer in vessels 
lined with the precious metal. It's potent enough that the U.S. 
Environmental Protection Agency (EPA) regulates silver as a 
pesticide. Which raises the question: What does nanosilver do to the 
"good bugs" downstream, at the sewage treatment plant and elsewhere?

In 2006, a trade organization of wastewater treatment operators was 
concerned enough about a new silver-ion-emitting Samsung washing 
machine to pressure the EPA to include such equipment under its 
pesticide rules. The EPA responded by cracking down, not only on the 
washer but also on manufacturers of products advertised to contain 
nanosilver, including a line of supposedly sanitary computer 
peripherals. Separately, a coalition of consumer, health, and 
environmental groups filed a petition last year asking the EPA to 
impose a moratorium on nanosilver products until more safety research 
is done. In addition, the EPA has awarded a grant to Arizona State 
researchers to investigate interactions between various kinds of 
nanomaterials and wastewater biosolids.

Oversight or Overlooked?

In the U.S., the EPA has emerged as the lead agency on nano 
oversight. But that's not saying much. It is wrestling with the 
possible risks of nanomaterials, but so far has taken almost no 
action to regulate them.

In a voluntary Nanoscale Materials Stewardship Program, the EPA asked 
companies to submit information about what nanomaterials they're 
using. Very few did, and even the companies that participated 
withheld large amounts of data as business secrets. This March, the 
EPA began requiring manufacturers of carbon nanotubes to file 
pre-manufacturing notices under the Toxic Substances Control Act. 
California is requiring carbon nanotube makers to share their 
environmental, health and safety test data with the state, and is 
considering imposing the same mandate on makers of nanometal oxides, 
like the ones Gruden is testing.

But the EPA is not the only federal agency with responsibility for 
nanomaterials. Cosmetics, sunscreen, and food and beverages-which 
fall under the jurisdiction of the Food and Drug Administration 
(FDA)-make up roughly 30% of PEN's consumer products inventory. Yet 
the FDA is poorly equipped to ensure the safety of nano-containing 
dietary supplements, according to a 2008 report by two former agency 
officials. (Friends of the Earth has urged mandatory labeling of 
nanofoods and a moratorium on nano-containing cosmetics until they're 
shown to be safe.) The Occupational Safety and Health Administration, 
which is responsible for protecting workers, has not even begun to 
work on nano rules.

A former EPA official, J. Clarence Davies, proposes merging all these 
agencies and more into a new Department of Environmental and Consumer 
Protection. A "scientific agency with a strong oversight component," 
it would cover products, pollution, workplace health and safety, 
climate change and health effects of nanotechnology as well as other 
technologies, Davies writes in his April 2009 report, "Oversight of 
Next Generation Nanotechnology."

Outside the U. S., regulators are taking a somewhat more 
precautionary approach. Still, governments have adopted very few 
nano-specific rules to protect people or the environment. But there 
are bright spots. At Rice University in Houston, Texas, for example, 
Vicki Colvin and her colleagues are trying to engineer nanomaterials 
that are safe from the get-go, rather than looking for ways to 
minimize harm from nanotoxins.

But fears abound that the teeny genie is escaping from its bottle. 
The asbestos parallel causes particular concern-prompting the 
Australian Council of Trade Unions, for example, to call for that 
country to adopt nano regulations by year's end. At the Bethesda 
workshop in February, Harvard industrial hygienist Robert Herrick 
advocated an all-out effort to gather information about nano 
exposures and possible related illnesses. The asbestos industry could 
have undertaken a similar effort in the 1930s, he noted. Instead, 
industry execs decided to keep the subject quiet. If they had gone 
the other way, Herrick wondered, "how different would history be?"

CAROLE BASS, a journalist, writes about the environment, workplace 
health, legal affairs and other subjects