The carcinogenic effects of carbon black particles and tar-pitch condensation aerosol after inhalation exposure of rats

Carbon black (CB) particles almost completely devoid of organic compounds (Printex 90, Degussa), PAH-rich hard coal tar-pitch condensation aerosol (T-P aerosol) and mixtures of CB and T-P aerosol as well as T-P aerosol and a mixture of NO2, SO2 and formaldehyde were investigated for their carcinogenic effects in female Wistar rats after inhalation exposure for 43 or 86 weeks. No lung tumours occurred in the clean air controls. After 43 weeks of exposure to 6 mg(-3) CB, 12 out of 72 animals (17%) developed lung tumours.