Evaluating the Toxic Effects of Carbon Nanotubes On Soil Organisms.

The Nanoparticles known as carbon nanotubes (CNTs) will undoubtedly revolutionize research and industry, from sports equipment to cell therapy to computing. With such wide-spread potential comes the certainty that they will become common contaminants in many biological systems. The same properties that make CNTs so promising also make them a potentially hazardous contaminant. This research aims to determine the effects of CNTs on the industry-standard soil test organisms Eisenia andrei and Folsomia candida. Previous attempts to observe toxic effects of CNTs have involved attaching reactive functional groups to the particles, and the use of toxic dispersants. Additionally, it is extremely difficult to detect the presence of CNTs in soil. This research aims to eliminate these compounding factors by removing them: non-functionalized multiwalled carbon nanotubes have been used, and used without the aid of dispersants. A method has been developed in which CNTs are combined into a slurry with silica sand in order to make a stock ̉solutionÓ. This was then used to spike artificial soil, to which E. andrei and F. candida are exposed in Environment Canada standard test methods to determine the acute and reproductive toxic effects. Preliminary results suggest that at exposures of 1000mg/kg CNTs and higher, there is significant reduction in adult invertebrate survival and reproduction.