Studies of ozone toxicity. I. Potentiating effects of exercise and tolerance development.

Abstract

Although rats exposed to 1 ppM ozone 6 h/d for 200 days or subjected to exercise had no mortality, 11 out of 20 rats exposed to ozone plus exercise died. There were similar responses in mice but not in hamsters. LD/sub 50/ for hamster was found to be 10 ppm for 4 h, for rat: 4.8 ppM. Rats subjected to pre-exposure of 1 ppM O/sub 3/ (1 to 150 h) tolerated subsequent O/sub 3/-exercise regimen. Longer pre-exposure increases survival. Tolerance from single exposure of 1 ppM for 6 h extends for 4 to 6 weeks.