[Pulmonary toxicity of manufactured nanomaterials].
We introduced the report on the pulmonary toxicity of manufactured nanomaterials as a national project in Japan conducted by the New Energy and Industrial Technology Development Organization (NEDO project). Well-characterized and well-dispersed industrial nanomaterials were used in this project. Using multiwall carbon nanotubes (MWCNTs), we conducted intratracheal instillation and inhalation studies. At a low dose (0.2 mg/rat) and a high dose (1 mg/rat) of almost individual MWCNTs, transient and persistent inflammatory responses were induced in the lungs following intratracheal instillation. Well-dispersed MWCNTs at a low concentration (0.37 mg/m3) did not induce pulmonary inflammation. Using single-wall carbon nanotubes (SWCNTs), we also conducted both studies. At low (0.2 mg/rat) and high doses (0.4 mg/rat) of well-dispersed SWCNTs, persistent inflammatory responses were induced in the lungs following intratracheal instillation. Well-dispersed MWCNTs at low and high concentrations (0.03 mg/m3 and 0.13 mg/m3, respectively) did not induce pulmonary inflammation. On the basis of these data from mainly inhalation studies, the acceptable exposure concentration of carbon nanotubes is proposed to be 0.03 mg/m3 in Japan.
Department of Occupational Pneumology, University of Occupational and Environmental Health, Japan. yasuom@med.uoeh-u.ac.jp
Yasuo
Y
Morimoto
D000280:Administration, Inhalation; D000818:Animals; D019570:Inhalation Exposure; D008168:Lung / Q000187:drug effects*; D008452:Maximum Allowable Concentration; D049329:Nanostructures / Q000633:toxicity*; D037742:Nanotubes, Carbon / Q000633:toxicity; D011014:Pneumonia / Q000139:chemically induced; D051381:Rats
D037742:Nanotubes, Carbon