[State and treat on the health effect of nanomaterial]

The health effects of nanomaterial have been paid attention, however it is unclear in detail. There are some reports that low dose and/or low concentration of nanoparticles induce pulmonary inflammation and/or fibrosis in animal studies and that nanoparticles were found not only in lung, direct exposed organ but also other organs such as liver, kidney and brain. We introduced the report of relationship between the responses and physicochemical properties of nanoparticles and of paradigm of lung disorder induced by nanoparticles. The surface, length and the presence of transition metals are important factors to reflect the pulmonary response. We also introduced acceptable exposure concentration of nanoparticles such as titanium dioxide, fullerene and carbon nanotube in Japan.