Genotoxicity of inhaled nanosized TiO2 in mice

► Mice inhaled nanosized TiO2 anatase-brookite (0.8, 7.2, or 28.5 mg/m3) for 5 days. ► A dose-dependent deposition of Ti in lung tissue was seen. ► No increase in DNA damage was observed in lung epithelial cells. ► No induction of micronuclei was detected in blood polychromatic erythrocytes. ► A clear pulmonary neutrophilia was, however, present at 28.5 mg/m3 TiO2. ► Systemic TiO2 doses were much lower than in previous positive oral and i.p. studies.