Nanotoxicology is a complex field but the synergistic effects of nanoparticles are now being studied. Guo, Zebda, Drake and Sayes have just published a paper in Particle and Fibre Toxicology (2009, 6:4) titled Synergistic effect of co-exposure to carbon black and Fe2O3 nanoparticles on oxidative stress in cultured lung epithelial cells
Here, carbon black and iron oxide nanoparticles were found to be more toxic as a mixture than either nanoparticle separately. The toxicity of carbon black has been known for many years.
This type of of research does point to increasing the complexity of evaluating nanomaterials. It will be also interesting to see unexpected toxicities in nanomaterials made from material that had low toxicities in their bulk form.
