Ozone-induced micronuclei frequency in rat alveolar type II cells

The effect of ozone, a ubiquitous air pollutant, was tested on cultured pul monary 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 mi cronucleated cells was counted after the exposure. In each group, 17 000 ce lls were evaluated. The number of micronucleated cells was significantly in creased in the ozone-exposed group (12.24 per 1000 cells) compared to the c ontrol group (5.00 per 1000 cells). The results showed the mutagenic effect of ozone exposure on alveolar type II cells, manifested in the increased f requency of their micronuclei.