Nissan Motor Co has formed a partnership with Tennessee to study the infrastructure needed to support the roll-out of electric cars starting in 2011, Nissan Chief Executive Carlos Ghosn said on Tuesday.

"We are forming a partnership with the state of Tennessee to promote zero-emission mobility," Ghosn said at the opening of the Japanese automaker's new headquarters in Nashville.

More risk assessment studies are needed to understand what exactly defines toxicity due to nanoparticles, and what kind of regulations the sector needs, said Hermann Stamm, head of nanotechnology and molecular imaging at the Institute for Health and Consumer Protection in the European Commission's Joint Research Council.