Induction of mutations and chromosome aberrations in lung cells following in vivo exposure of rats to nitrogen oxides.

In order to investigate the mutagenic effects of nitrogen oxides ( NOx ), induced mutations and chromosome aberrations were examined using primary lung cells obtained from rats exposed in vivo to NO2 and NO. Rats were exposed to nitrogen oxide gases at concentrations of 8-27 ppm for 3 h in a stainless steel chamber. Over the range 15-27 ppm, NO2 significantly increased mutation to ouabain resistance. Over a similar dose range, NO significantly increased mutation only at the highest concentration (27 ppm). Following NO2 exposure, chromosome aberrations (mainly chromatid type) were induced in chromatid breaks, 2.5-11.6-fold over the control at 8 and 27 ppm, respectively.