Are nanoparticles harmful to the environment?

Even though nanoparticles are everywhere — including your back yard — their safety is something that researchers are still trying to understand…

By Elizabeth Dougherty

Not all nanomaterials are man-made. In fact, some, such as tiny viruses, are probably growing in the soil in your backyard right now. Recently, however, more and more engineered nanoparticles are being introduced into the products we use every day — medicine, food, cleaning products, cosmetics, electronics, and more. Even though nanoparticles are everywhere, their safety is something that researchers are still trying to understand. “It’s an evolving science,” says MIT biological engineering and materials science and engineering professor Angela Belcher.

There is some evidence that engineered nanoparticles might cause harm to the environment. One recent study found that nanosilver particles, engineered to keep socks from getting smelly, can leech into the water supply; it isn’t clear yet if they have the potential to do harm once they get there. Other research showed that certain types of carbon-based nanoparticles may cause lung or DNA damage. Despite these findings there are few checks in place to ensure that nanoparticles are used safely, so the Environmental Protection Agency is considering tighter controls of them.

Belcher’s work with engineered nanoparticles, however, turns the safety question on its head. The particles she specifically creates are designed to reduce environmental harm and are produced through comparatively non-artificial methods. Her synthetic nanoscale objects are organic in nature, and they “grow” materials such as electronics, solar cells, and batteries in the cleanest, most environmentally friendly way possible.

Using biological and genetic engineering, Belcher “evolves” organisms in her laboratory to harness and assemble elemental materials under natural conditions. That is, she says, they don’t require extreme heat, pressure, or solvents to build electronics or other products. “These organisms build structures the same way abalone build shells,” she says. “Abalone use no toxic materials. Instead, they use only what’s in their environment, like sea water. That’s the model for how we make materials.”

Posted: September 15, 2009