Lymphocyte DNA damage in cigarette factory workers measured by the Comet assay

To investigate whether there were separate and combined effects of occupati onal exposure to tobacco dust and smoking on lymphocyte DNA damage, 148 wor kers from a cigarette manufacturing factory (107 occupationally exposed to tobacco dust from the production department and 41 unexposed controls who w ere managerial workers) were included in the study. The Tail Moment (TM) of Comet assay was used to measure DNA damage. The two groups had similar mea n age, mean duration of work and smoking prevalence. The exposed workers ha d a larger TM than that of the controls (mean +/- S.D.: 43.43 +/- 13.77 vs. 38.89 +/- 8.98, p < 0.05). Smokers had significantly larger TM than non-sm okers (47.25 +/- 14.02 vs. 38.90 +/- 10.75, p < 0.001). Analysis of varianc e after adjustment for age and gender showed that occupational exposure and smoking had a significant and independent effect on Tail Moment(p = 0.025 and p = 0.002, respectively) and there was a significant positive two way i nteraction between the two factors (p = 0.019). Age and gender had no signi ficant effect on TM. The present study suggests that smoking and tobacco du st exposure can induce lymphocyte DNA damage and there is a synergistic eff ect of tobacco dust exposure and smoking on DNA damage. (C) 1999 Elsevier S cience B.V. All rights reserved.