Sister chromatid exchanges in smokers of high-tar cigarettes, low-tar cigarettes, cheroots and pipe tobacco.

Smoking is correlated to cancer and it has previously been shown that cigarette smokers have increased SCE compared to non-smokers. We have now examined SCE in 189 smokers of different types of tobacco and 60 non-smokers. 64 smokers of high-tar cigarettes with filter had 9.47 ± 0.15 SCE/cell (mean and SEM). 42 smokers of high-tar cigarettes without filter had 9.19 ± 0.19 SCE/cell and 23 smokers of low-tar cigarettes with filter had 8.97 ± 0.24 SCE/cell. The average cigarette consumption per day was from 15 to 17 in the different groups. The differences in SCE between the groups were not statistically significant. The 60 non-smokers had 8.25 ± 0.13 SCE/cell. All the cigarette smokers had SCE values significantly higher than the non-smokers (P<0.01). The 30 cheroot smokers had 10.47 ± 0.38 SCE/cell, significantly higher than the non-smoking group (P<0.001). The average daily consumption was 8.3 cheroots. The 30 pipe smokers had an SCE count of 9.60 ± 0.23, significantly higher than the non-smoking group (P<0.001). The daily tobacco consumption was 13.7 g. Thus all smokers of different tobacco types have increased SCE. We found no relation between condensate and filter in cigarettes and SCE.