Oviductural carcinoma in B6C3F1 female mice exposed to 0.5 ppm ozone

The toxicity and carcinogenecity of ozone was evaluated in B6C3Fl mice exposed to 0.5 ppm ozone via inhalation for 12 w, during which no ozone-related deaths occurred. Decreases in mean body weights of both genders exposed to ozone were sporadically seen, and mean absolute and relative weights of several organs from male and female groups receiving ozone were lower than those of respective air-control groups. No ozone-related increased neoplasm incidences were observed in most organs, including the lung; however, oviductural carcinomas were seen in the ozone-exposed females. Although ozone does not induce lung cancer under our experimental condition, it induces oviductural carcinomas in B6C3Fl mice.