Increased sister chromatid exchange frequency in lymphocytes in healthy cigarette smokers.

Abstract

SCE rates in peripheral lymphocytes may be useful for evaluation of environmental mutagens. Since lung cancer is strongly associated with cigarette smoking, an association of SCE with cigarette smoking might be of interest. Controversy about this question prompted the present study of SCE in peripheral lymphocytes in 149 healthy, unmedicated persons. 60 non-smokers had 8.25 ± 0.13 SCE/cell (mean value ± standard error of the mean), and 89 cigarette smokers had 9.23 ± 0.14 SCE/cell. The sum of SCE in 30 metaphases in each person was transformed to a normally distributed metameter, y= (SCE)½+ (SCE+1)½, which was found to be significantly increased with increasing cigarette consumption. The linear regression calculated for y= (SCE)½+(SCE+1)½ and x=number of cigarettes smoked per day was y=31.43+0.094 x. It was concluded that cigarette smokers have increased SCE in peripheral lymphocytes. The significance of this in respect to risk of development of cancer in the lung is unknown. The influence of cigarette smoking should be considered when using the SCE test principle to evaluate in vivo exposure to potential mutagens.