Tubes in the Mud

The Good and Bad News about Nanotube Pollution in Wetlands
October 13, 2014

Carbon nanotubes are among the most useful forms of nanotechnology. They can be used in everything from electrical circuits to building materials. In order to use this technology responsibly, however, scientists and engineers need to understand how it might affect the environment.

That in mind, Lee Ferguson, a civil engineering professor at Duke University’s Pratt School of Engineering, recently published a study on the effects of single-walled carbon nanotubes in wetlands.

Ferguson and his colleagues created several artificial swamps and added carbon nanotubes to them. After 10 months, Ferguson tested the soil, plants and animals in his mini-wetlands for carbon nanotubes. The results have good news and bad news.

The good news: The researchers did not find that the nanotubes accumulated very much in the fish, plants or water; meaning that over 10 months things that eat those fish or drink the water wouldn’t really get much of that pollution. It’s also good news for the fish and plants, as they weren’t really affected.

The bad news: The nanotubes quickly piled up in the mud and sediment at the bottom of the mini-wetlands. The trouble with that is that nanotubes do not degrade quickly and they can latch on to other pollutants and keep them in the mud. This could bode ill for the tiny organisms living in the mud. Also, since nanotubes can last a long time, they may not harm a wetland in 10 months, but may have an adverse effect years or decades down the road.

Scientists still understand little about how carbon nanotubes may or may not affect the environment, but studies like this one can help to slowly piece that picture together. Ferguson’s study was published in the journal Environmental Science: Nano.

- Daniel Lane

Daniel Lane covers science, engineering, medicine and the environment in North Carolina.