Experts Explore Risks of Nanotechnology in Clothes

(Dec. 4) -- Tiny particles so small that at least a million of them can fit on a pinhead are keeping your bras, panties, socks and children's clothing smelling sweet. But are these silver nanoparticles safe?

An Environmental Protection Agency science panel opened a four-day hearing Tuesday in Washington, examining the hazards associated with nanosilver, an odor-fighting, bacteria-killing material used in thousands of clothing items.

And Swiss scientists this week will release what they say is the first comprehensive study on the escape of silver nanoparticles from clothing to rivers, streams and lakes, often major sources of drinking water.

ALSO SEE: List: Products Containing Nanosilver

The Swiss study is being published this week in the American Chemical Society's journal Environmental Science & Technology. In it, scientists measured the nanosilver particles released from a variety of brands of socks made from different textiles. Most of the amounts released in the wash were relatively large, they found, and as much as 35 percent of the total silver came out of the fabrics during the first wash.

Most filters in water treatment plants are unable to screen out the nano-sized particles of silver, which may be no thicker than 1/50,000th the width of a human hair.

"These results have important implications for the risk assessment of silver textiles and also for environmental fate studies of nanosilver," said Dr. Bernd Nowack and his colleagues from the Swiss Federal Laboratories for Materials Testing and Research.

Scientists have shown that silver in many forms has great medicinal effects, including being toxic to most bacteria, viruses and fungi.

But no one has yet completed, or at least published, research on whether nano-sized silver in the water may harm the people and animals who drink it or the environment.

The problem is much bigger than a load of socks in the wash. Consider that there are thousands of individual items -- from frilly bras to underwear for astronauts and campers -- that tout nanosilver as an antibacterial agent.

Clothing for infants and children may provide the biggest payday. Marketers count on new parents' fears of germs to sell an almost endless list of products that will kill the bugs on things their offspring may put in their mouths.

And the products are heavily promoted.

The Korean electronics manufacturer Samsung had a Hollywood-style gala to launch its Silver Wash clothes washer with a nanosilver-coated drum that it said it would kill more than 600 different bacteria.

Many high-end women's and design magazines have slick ads proclaiming that the Silver Wash machine "achieved 99.9 percent sterilization of bacteria'' and leaves behind a residual silver coating on clothing "to keep it smelling fresh for up to 30 days."

Andrew Maynard, chief science adviser for the Project on Emerging Nanotechnologies, warned Congress last year that hundreds of products with nanoparticles are on the market, with three to five new ones added every week.

"What we know at the moment is that silver does have the potential to cause environmental harm if released in sufficient quantities, and that silver used as nanoparticles might exacerbate the problem in some circumstances," he told me this weekend.

He is concerned that current research won't provide a clear picture of potential risks presented by nano-scale silver for some time.

"And it's not even clear whether the right research is being funded -- in other words, there's a disconnect between where we need to be on nanosilver, and what we are doing to get there," added Maynard, who's at the Woodrow Wilson International Center for Scholars.

In June 2008, The International Center for Technology Assessment and a coalition of consumer, health and environmental groups filed a petition with the EPA demanding the agency use its pesticide regulation authority to stop the sale of hundreds of consumer products now using nano-sized versions of silver.

No one involved in the nano safety fight could tell me of any products the EPA pulled off the market. But the EPA declared Samsung's Silver Wash a pesticide.

The EPA's nano Scientific Advisory Panel is evaluating statements on the "assessment of hazard and exposure associated with nanosilver."

The panel will hear from scientists, toxicologists, public health specialists and representative of the nanosilver industry.

Here are three of the many topics they are likely to debate, or at least consider as they ponder what regulations this multibillion-dollar industry needs and will accept:

-- An antibacterial agent such as nanosilver is a pesticide, and with that designation comes safety restrictions that manufacturers fight to avoid.

-- Nanosilver kills harmful bacteria, but it doesn't distinguish between good and bad bacteria. This means it also could kill microbes that water treatment plants need to operate and that we need to live.

-- The potential hazards associated with exposure to nano particles -- both metals and chemicals -- are likely to differ from the same substance that hasn't been reduced in size.

The most common reply when nano scientists and marketers are asked about the safety of their almost invisible creations is something like: "Well, we know the toxicity limits for (insert chemical of your choice). Why should we test it just because we've made it smaller?"

Many toxicologists and public health specialists disagree.

"Unfortunately, that's the mantra," Maynard said. "One size fits all is not a viable concept when it comes to assessing risk or toxicity of any substance."

Dr. Jennifer Sass, senior scientist and nano specialist for the Natural Resources Defense Council, has long been concerned about the toxicity of nano particles.

In material she submitted to the EPA panel, Sass said that unless multiple, well-designed studies demonstrate otherwise, nano-sized material should not be automatically declared safe.

Sass, who for years has studied EPA and industry's testing for children's exposure to toxic material, said the NRDC is particularly concerned about exposure to infants and children through the use of nanosilver and other nano-chemical antimicrobials.

Many who will attend the hearings or who submitted testimony believe passionately that no new government regulations are needed.

For example, some groups that sell nutritional, cosmetics or medical supplements made with silver are adamantly against EPA imposing any controls on silver products.


They insist that nutritional supplements containing nanosilver have never been demonstrated to pose any threat to the environment whatsoever.

Other federal and state agencies will be watching the outcome of the EPA's effort.

Almost everyone sees the enormous actual and potential benefit to medicine, engineering and a hundred other fields from the advances in nanotechnology. But many people in government, public health and the nano industry worry that there must be some mechanism to weigh the benefits against what could be an enormous risk.