Researchers urge caution in manufacturing, stepping up waste management oversight
By Summit Voice
SUMMIT COUNTY — Carbon nanotubes, valuable for strengthening industrial and recreational products, can kill aquatic organisms, according to University of Alaska and U.S. Geological Survey researchers, who said it’s important to guard against release of the materials into the environment as the materials enter mass production.
“The great promise of carbon nanotubes must be balanced with caution and preparation,” said Baolin Deng, professor and chair of chemical engineering at the University of Missouri. “We don’t know enough about their effects on the environment and human health. The EPA and other regulatory groups need more studies like ours to provide information on the safety of CNTs.”
CNTs are microscopically thin cylinders of carbon atoms that can be hundreds of millions of times longer than they are wide, but they are not pure carbon. Nickel, chromium and other metals used in the manufacturing process can remain as impurities.
Deng and his colleagues found that these metals and the CNTs themselves can reduce the growth rates or even kill some species of aquatic organisms. The four species used in the experiment were mussels (Villosa iris), small flies’ larvae (Chironomus dilutus), worms (Lumbriculus variegatus) and crustaceans (Hyalella azteca).
“One of the greatest possibilities of contamination of the environment by CNTs comes during the manufacture of composite materials,” said Hao Li, associate professor of mechanical and aerospace engineering at MU. “Good waste management and handling procedures can minimize this risk. Also, to control long-term risks, we need to understand what happens when these composite materials break down.”
The study on CNTs toxicity to aquatic animals was a collaboration between engineering faculty and students at MU and U.S. Geological Survey researchers led by Christopher Ingersoll.