Cellular effects of smoke from "safer" cigarettes.

Mutagenicity and cytotoxicity are basic cellular effects of cigarette smoke which underlie the development of lung cancer and chronic obstructive airways disease. This study reports that, on a weight-for-weight basis, cigarette smoke condensates from low, middle and high tar cigarettes produce similar mutagenic effects detected by induced sister chromatid exchanges and similar cytotoxic effects detected by vital dye exclusion in human leucocytes. These findings, taken with the strong evidence that smokers extract more smoke from lower tar cigarettes to compensate for low nicotine yields, suggest that the health dangers associated with smoking these "safer" products are underestimated.