Comparative genotoxicity testing of airborne particulates using rodent tracheal epithelial cells and human lymphocytes in vitro.

In our study samples of airborne particulates were collected in the heavily industrialized Rhine-Ruhr region utilizing a high volume sampler HVS 150 (Ströhlein Instruments) equipped with glass fibre filters. Chemical substances were extracted from filters with dichloromethane and quantitatively transferred to dimethyl sulfoxide (DMSO) for tissue culture experiments. For detection of genotoxicity of extract of airborne particulates we utilized as a sensitive bioassay the induction of 'sister chromatid exchanges' (SCE) in cultures of human lymphocytes and of tracheal epithelial cells of the Syrian golden hamster. The extract of airborne particulates was added in various concentrations to cell cultures of human lymphocytes and hamster tracheal epithelial cells in presence of bromodeoxyuridine for 72 or 48 h, the last 3 h in presence of demecolcine or nocodazole, respectively. Extract of airborne particulates led in both test systems--human lymphocytes and tracheal epithelial cells of the hamster--to a dose-dependent, highly significant induction of 'sister chromatid exchanges'. Very low quantities of substances corresponding to airborne particulates from less than 1 m3 air were highly effective in both cell systems. In comparison, tracheal epithelial cells of the Syrian golden hamster revealed a higher sensitivity showing a steeper increase of 'sister chromatid exchanges' than human lymphocytes.