Increasingly, we hear about the use of nanoparticles and nanotechnology in new products. Tiny particles of silver act as anti-microbial agents in clothing. Similarly small particles of titanium enhance the brightness and application of paints, cosmetics, and sunscreen. And particles of a rare element, cerium, remove otherwise noxious components from diesel exhaust.
But nanoparticles have a flip-side, which we don’t understand particularly well. Studies of air pollutants have focused on particles <2.5 microns in diameter. These are deeply inhaled, causing respiratory problems. Nanoparticles are 25 times smaller.
Nanoparticles are released to the environment when we dry clothes that contain them as anti-wrinkling components, when we burn diesel fuel that contains cerium oxide, and when we wash antimicrobial agents in soaps down the drain. About 40,000 tons of nanoparticles are produced each year in the U.S.
Environmental scientists admit that they don’t know much about the effects of these small particles in the environment. It’s not just about the size of the particles—nature has always exposed us to small particles—it’s what they contain. Silver nanoparticles are toxic to the bacteria that we expect to clean up sewage effluents. And, a number of nanoparticles are known to be taken up by plants and transferred to higher life forms—including us—when plants are eaten.
When it comes to new products in the environment, precaution is often wisdom. Let’s support basic science about nanoparticles and see what it says.
Photo, taken on February 2, 2012, courtesy of IBM Research via Flickr.