Carbon "nanotubes" mimic the toxic qualities of asbestos, according to a U.S.-based Project on Emerging Nanotechnologies.

Boffins injected mice with asbestos and with commercial samples of carbon nanotubes of varying sizes. When they opened up the mice, they found that the longer nanotubes behaved like asbestos, provoking inflammation and lesions. The researchers want companies developing carbon nanotube-based materials to reveal whether they are using longer strands such as the ones that appear to act like asbestos.

Earlier research in Japan,found that mice injected with carbon nanotubes developed mesothelioma. But the doses of carbon nanotubes were so high they would have killed an elephant.