Tracheal epithelial cells in vitro as a model to study genotoxicity of airborne particulates

The major target site of airborne particulates is the tracheobronchial epithelium of the respiratory tract. It is also the origin of the most common cancer in man, bronchogenic carcinoma. Rodent tracheal epithelial cells in culture can be used to study the genotoxic activity of airborne particulates leading to mutation and cancer. Airborne particulates were collected in the heavily industrialized Rhine-Ruhr region using a high volume sampler HVS 150 (Ströhlein Instruments) equipped with glass fibre filters. Chemical substances were extracted with di-chloromethane or methanol and quantitatively transferred to dimethyl sulfoxide for tissue culture experiments. Tracheal epithelial cells of the Syrian golden hamster and the Wistar rat were dissociated by pronase treatment and cultivated in a 'complex' medium. The induction of sister chromatid exchanges was used as a sensitive bioassay for detection of genotoxic activity of airborne particulates. Extracts of airborne particulates led to a dose-related highly significant induction of sister chromatid exchanges in cell cultures of tracheal epithelial cells of the hamster and the rat. Even quantities of chemical substances equivalent to airborne particulates from less than 1 m(3) air were markedly genotoxic.