RODALE NEWS, EMMAUS, PA—What do your iPhone, your underwear, and your vacuum cleaner all have in common? They can all be made with nanoparticles, tiny particles 1/100,000th the width of a human hair. While nano-sized particles of various materials can keep stains from sticking to your pants, improve the look of your cosmetics, and make your bike so light you can lift it with a pinky, there is very little known about what these particles do to the environment or the human body. And given their increasingly widespread use, the results of a spate of new studies cast a disturbing look at this tiny technology.
THE DETAILS: When the nonprofit Project on Emerging Nanotechnologies (PEN) started cataloguing products that contained nanoparticles and nanomaterials in 2006, they counted 212. As of August 2009, that number has nearly quadrupled to 1,015, and at least three quarters of those products are designed for the ordinary consumer, despite the fact that the long-term health effects of these particles is completely unknown. The largest group of products, at 605 total, falls into the "health and fitness" category, encompassing cosmetics, clothing, personal-care products, sporting goods, sunscreens, and air and water filters. Nanomaterials are also used in food storage and cookware—even plastic beer bottles and McDonald's clamshell containers—along with electronics, fabric coatings, and household cleaners.
Research on nanotechnology is still in its early stages, but already scientists are sounding alarms. At the recent meeting of the Society of Environmental Toxicology and Chemistry (SETAC), more than 20 studies were presented on the fate of nanoparticles once they enter the environment, and nearly all found that these materials were building up in organisms, such as earthworms, insects, and fish, and having subtle effects on their abilities to survive. Of particular concern are silver nanoparticles, the most ubiquitous nanomaterial in use today, according to PEN. They are used as an antimicrobial in athletic socks and clothing, food containers, and cutting boards due to their effectiveness at killing bacteria without triggering resistance, says Marie-Noële Croteau, PhD, research biologist with the U.S. Geological Survey and author of one of the nanoparticle studies presented at the meeting. At one time, a Samsung brand washing machine was being sold in the U.S. that released nanosilver particles in the wash water as an "ecofriendly" alternative to bleach (the company quit selling them after the Environmental Protection Agency required that the machines be listed as pesticides, due to the harmful affects of silver on wildlife). "In nano form, silver can be potentially toxic," Croteau says, to both animals and people. "Once these particles are in nature, in the water system, they're going to bind to sediment in the water and settle down on the bottom [of lakes and rivers]." Her study found that high levels of metal nanoparticles interfered with aquatic organisms' ability to feed, which has repercussions up the food chain. Another study found that once nanosilver is washed down the drain, it's highly effective at killing the microorganisms used to treat sewage in wastewater treatment plants, which could lead to bigger problems with drinking-water safety.
Published on: December 7, 2009