Non-Engineered Nanoparticles of C(60)

We discovered that rubbing bulk solids of C(60) between fingertips generates nanoparticles including the ones smaller than 20 nm. Considering the difficulties usually associated with nanoparticle production by pulverisation, formation of nanoparticles by such a mundane method is unprecedented and noteworthy. We also found that nanoparticles of C(60) could be generated from bulk solids incidentally without deliberate engineering of any sort. Our findings imply that there exist highly unusual human exposure routes to nanoparticles of C(60), and elucidating formation mechanisms of nanoparticles is crucial in assessing their environmental impacts.