Ozone-induced micronuclei frequency in rat alveolar Type II cells.

The effect of ozone, a ubiquitous air pollutant, was tested on cultured pulmonary epithelial type II cells isolated from rats. After 40-hour culture, the cells were exposed for 6 h to 400 ppb of ozone or air. The number of micronucleated cells was counted after the exposure. In each group, 17000 cells were evaluated. The number of micronucleated cells was significantly increased in the ozone-exposed group (12.24 per 1000 cells) compared to the control group (5.00 per 1000 cells). The results showed the mutagenic effect of ozone exposure on alveolar type II cells, manifested in the increased frequency of their micronuclei.